Physical and mechanical properties of PLA, and their functions in widespread applications — A comprehensive review

Raw PLA material exhibited slightly higher thermal stability (~331 °C) than processed materials (323-325 °C).

“Raw material exhibited slightly higher thermal stability (~331 °C) than processed materials (323-325 °C) (Table 5).”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Extruded/injected PLA materials showed a significant increase in elongation at break (32-35% higher) compared to injected materials.

“Extruded/injected materials showed a significant increase in elongation at break (32-35% higher), compared to injected materials.”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

X-ray diffraction showed 45-47% crystallinity for annealed PLA materials.

“These findings were corroborated by DSC (degrees of crystallinity of 4% for injected material, 8% for extruded/ injected material and 33-35% for annealed materials) and X-ray diffraction (45-47% for annealed materials).”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Thermal decomposition of PLA occurred within the temperature range of 325-375 °C.

“Thermal decomposition occurred within the temperature range of 325-375 °C.”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Strain at break of PLA decreased from 0.060 to 0.025 and 0.005 mm/mm after 3 and 7 injection cycles, respectively.

“Stress at break was found to decrease from 66.5 to 56.0 and 23.0 MPa, and strain at break from 0.060 to 0.025 and 0.005 mm/mm after 3 and 7 injection cycles respectively [155].”

• cites [155] 155. I. Pillin, N. Montrelay, A. Bourmaud, Y. Grohens, Polym. Degrad. Stab. 93 (2008) 321-328.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Stress at break of PLA decreased from 66.5 to 56.0 and 23.0 MPa after 3 and 7 injection cycles, respectively.

“Stress at break was found to decrease from 66.5 to 56.0 and 23.0 MPa, and strain at break from 0.060 to 0.025 and 0.005 mm/mm after 3 and 7 injection cycles respectively [155].”

• cites [155] 155. I. Pillin, N. Montrelay, A. Bourmaud, Y. Grohens, Polym. Degrad. Stab. 93 (2008) 321-328.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Flax/PLLA composites undergo permanent changes after immersion in seawater.

“The results showed also that flax/PLLA composites undergo permanent changes after immersion in seawater.”

• cites [219] 219. D. Rasselet, A. Ruellan, A. Guinault, G. Miquelard-Garnier, C. Sollogoub, B. Fayolle, Eur. Polym. J. 50 (2014) 109-116.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The greatest overall reduction in tensile strength, flexural strength, Young's modulus, and flexural modulus was observed for AUL composites than for AAL composites.

“The greatest overall reduction in TS, flexural strength, YM, and flexural modulus was observed for AUL composites than for AAL composites.”

• cites [216] 216. Y. Chen, J.F. Davalos, I. Ray, H.Y. Kim, Compos. Struct. 78 (2007) 101-111.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

A reduction in tensile strength, flexural strength, Young's modulus, and flexural modulus from their mean values for neat PLA and composites with increased aging duration was observed.

“A reduction in tensile strength (TS), flexural strength, Young's modulus (YM), and flexural modulus from their mean values for neat PLA and composites with increased aging duration was observed (Table 12).”

• cites [216] 216. Y. Chen, J.F. Davalos, I. Ray, H.Y. Kim, Compos. Struct. 78 (2007) 101-111.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

There is limited information regarding aging under several conditions for plasticized PLA blends.

“Although, huge attempts to improve PLA physical-mechanical properties for packaging or medical applications using plasticizers have been reported, there is limited information found regarding aging under several conditions for these blends.”

Lactic acid can be made by fermentation of sugars obtained from renewable resources such as sugarcane or corn starch.

“Lactic acid can be made by fermentation of sugars obtained from renewable resources as such sugarcane or corn starch [4].”

• cites [4] 4. Handbook of Polymer Applications in Medicine and Medical DevicesPublished by Elsevier Inc.©, 2014, http://dx.doi.org/10.1016/B978-0-323-22805-3.00003-7. sourceNot checked — no full text of the source

PLA tensile strength and elastic modulus are comparable to poly(ethylene terephthalate) (PET).

“Although its tensile strength and elastic modulus are comparable to poly(ethylene terephthalate) (PET) [17,18], the poor toughness limits its use in the applications that need plastic deformation at higher stress levels (e.g., screws and fracture fixation plates) [15].”

• cites [17] 17. R. Auras, B. Harte, S. Selke, Macromol. Biosci. 4 (2004) 835-864.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [18] 18. S. Farah, K.R. Kunduru, A. Basu, A.J. Domb. Edition: 1st edition, Chapter: 8, Publisher: Elsevier, Editors: P. M. Visakh, M. Liang, 2015, pp. 143-165. sourceNot checked — no full text of the source

The FDA has approved PLA for direct contacting with biological fluids.

“The FDA has also approved PLA for direct contacting with biological fluids [16].”

• cites [16] 16. B. Gupta, N. Revagade, J. Hilborn, Prog. Polym. Sci. 32 (2007) 455-482.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA degradation rate depends on PLA crystallinity, Mw and its distribution, morphology, water diffusion rate into the polymer, and the stereoisomeric content.

“PLA degrades through the hydrolysis of backbone ester groups and the degradation rate depends on the PLA crystallinity, Mw and its distribution, morphology, water diffusion rate into the polymer, and the stereoisomeric content [20].”

• cites [20] 20. A.V. Janorkar, A.T. Metters, D.E. Hirt, Macromolecules 37 (2004) 9151-9159.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA production consumes carbon dioxide.

“Its production also consumes carbon dioxide [14].”

• cites [14] 14. J.R. Dorgan, H.J. Lehermeier, L.I. Palade, J. Cicero, Macromol. Symp. 175 (2001) 55-66.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA crystal forms are characterized by different helix conformations and cell symmetries, which develop upon different thermal and/or mechanical treatments.

“They are characterized by different helix conformations and cell symmetries, which develop upon different thermal and/or mechanical treatments [1].”

• cites [1] 1. M. Savioli Lopes, A.L. Jardini, R. Maciel Filho, Procedia Eng. 42 (2012) 1402-1413.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Poor toughness limits PLA use in applications that need plastic deformation at higher stress levels (e.g., screws and fracture fixation plates).

“Although its tensile strength and elastic modulus are comparable to poly(ethylene terephthalate) (PET) [17,18], the poor toughness limits its use in the applications that need plastic deformation at higher stress levels (e.g., screws and fracture fixation plates) [15].”

• cites [15] 15. R.M. Rasal, A.V. Janorkar, D.E. Hirta, Prog. Polym. Sci. 35 (2010) 338-356.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA is easily processable on standard plastic equipment to yield molded parts, film, or fibers.

“It is easily processable on standard plastic equipment to yield molded parts, film, or fibers [4,5].”

• cites [4] 4. Handbook of Polymer Applications in Medicine and Medical DevicesPublished by Elsevier Inc.©, 2014, http://dx.doi.org/10.1016/B978-0-323-22805-3.00003-7. sourceNot checked — no full text of the source
• cites [5] 5. D. Garlotta, J. Polym. Environ. 9 (2002) 63-84.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Environmental, economic, and safety challenges have provoked packaging scientists and producers to partially substitute petrochemical-based polymers with biodegradable ones.

“Environmental, economic, and safety challenges have provoked packaging scientists and producers to partially substitute petrochemicalbased polymers with biodegradable ones [3].”

• cites [3] 3. M. Jamshidian, E. Arab-Tehrany, M. Imran, M. Jacquot, S. Desobry, Compr. Rev. Food Sci. Food Saf. 9 (2010) 552-571.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Properties of PLA depend on its component isomers, processing temperature, annealing time and Mw.

“Properties of PLA depend on its component isomers, processing temperature, annealing time and Mw [6,24,25].”

• cites [6] 6. A.J. Lasprilla, G.A. Martinez, B.H. Lunelli, A.L. Jardini, R.M. Filho, Biotechnol. Adv. 30 (2012) 321-328.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [24] 24. T. Malmgren, J. Mays, M. Pyda, J. Therm. Anal. Calorim. 83 (2006) 35-40.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [25] 25. R. Franschini, R. Plesu, J.R. Sarasua, R.E. Prud home, J. Polym. Sci. Part B: Polym. Phys. 43 (2005) 3308-3315.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Lower energy use makes PLA production potentially advantageous with respect to cost.

“Lower energy use makes PLA production potentially advantageous with respect to cost as well.”

The crystallization kinetic of the branched polymer was faster than that of the linear analog.

“The crystallization kinetic of the branched polymer was faster than that of the linear analog.”

• cites [38] 38. J.R. Dorgan, H. Lehermeier, M. Mang, J. Polym. Environ. 8 (2000) 1-9.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA can be tailored by formulation involving co-polymerization of the lactide with other lactone-type monomers, hydrophilic macromonomers (PEG), other monomers with functional groups, or blending PLA with other materials.

“PLA can also be tailored by formulation involving co-polymerization of the lactide with other lactone-type monomers, hydrophilic macromonomers (PEG), other monomers with functional groups (such as amino and carboxylic groups), or blending PLA with other materials [6,40].”

• cites [6] 6. A.J. Lasprilla, G.A. Martinez, B.H. Lunelli, A.L. Jardini, R.M. Filho, Biotechnol. Adv. 30 (2012) 321-328.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [40] 40. Y. Cheng, S. Deng, P. Chen, R. Ruan, Front. Chem. Chin. 4 (2009) 259-264.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

In the second stage of PLA degradation, the Mw is reduced until the lactic acid and low Mw oligomers are naturally metabolized by microorganisms to yield carbon dioxide and water.

“In the second stage, the Mw is reduced until the lactic acid and low Mw oligomers are naturally metabolized by microorganisms to yield carbon dioxide and water [17,30].”

• cites [17] 17. R. Auras, B. Harte, S. Selke, Macromol. Biosci. 4 (2004) 835-864.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [30] 30. H.T. Oyama, Y. Tanaka, A. Kadosaka, Polym. Degrad. Stab. 94 (2009) 1419-1426.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA degradation occurs in two stages.

“PLA degradation occurs in two stages.”

• cites [17] 17. R. Auras, B. Harte, S. Selke, Macromol. Biosci. 4 (2004) 835-864.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [30] 30. H.T. Oyama, Y. Tanaka, A. Kadosaka, Polym. Degrad. Stab. 94 (2009) 1419-1426.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Physical characteristics such as density, heat capacity, and mechanical and rheological properties of PLA are dependent on its Tg.

“Physical characteristics such as density, heat capacity, and mechanical and rheological properties of PLA are dependent on its T g [8].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The Tm and degree of crystallinity depend on the molar mass, thermal history and purity of the polymer.

“The T m and degree of crystallinity are depended on the molar mass, thermal history and purity of the polymer [29].”

• cites [29] 29. A. Södergard, M. Stolt, Prog. Polym. Sci. 27 (2002) 1123-1163.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Shogren reported the water vapor transmission rate (WVTR) of crystalline and amorphous PLA at 6, 25, and 49 °C as 27, 82, and 333 g/m2 per day for the crystalline form and 54, 172, and 1100 g/m2 per day for the amorphous form, respectively.

“In an earlier study by Shogren the water vapor transmission rate (WVTR) of crystalline and amorphous PLA in 6, 25, and 49 °C was reported as 27, 82, and 333 g/m 2 per day for the crystalline form and 54, 172, and 1100 g/m 2 per day for the amorphous form, respectively [45].”

• cites [45] 45. R. Shogren, J. Environ. Polym. Degrad. 5 (1997) 91-95.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

For semicrystalline PLA, both Tg and Tm are important physical parameters for predicting PLA behavior.

“For semicrystalline PLA, both T g and T m are important physical parameters for predicting PLA behavior [17,27,28].”

• cites [17] 17. R. Auras, B. Harte, S. Selke, Macromol. Biosci. 4 (2004) 835-864.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [27] 27. L. Bouapao, H. Tsuji, K. Tashiro, J. Zhang, M. Hanesaka, Polymer 50 (2009) 4007-4017.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [28] 28. H. Tsuji, Y. Ikada, Polym. Degrad. Stab. 67 (2000) 179-189.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Due to higher crystallinity of biaxially oriented PLA film, CH4 permeation is 4.5 times lower than that of the other films.

“For example, due to higher crystallinity of biaxially oriented PLA film, CH 4 permeation is 4.5 times lower than that of the other films.”

• cites [38] 38. J.R. Dorgan, H. Lehermeier, M. Mang, J. Polym. Environ. 8 (2000) 1-9.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [43] 43. H.J. Lehermeier, J.R. Dorgan, J.D. Way, J. Membr. Sci. 190 (2001) 243-251.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [44] 44. K. Hamad, M. Kaseem, H.W. Yang, F. Deri, Y.G. Ko1, Express Polym Lett 9 (2015) 435-455.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA is suitable for packaging a wide range of food applications.

“As a consequence, PLA is suitable for packaging a wide range of food applications [3,47].”

• cites [3] 3. M. Jamshidian, E. Arab-Tehrany, M. Imran, M. Jacquot, S. Desobry, Compr. Rev. Food Sci. Food Saf. 9 (2010) 552-571.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [47] 47. R.A. Auras, S.P. Singh, J.J. Singh, Packag. Technol. Sci. 18 (2005) 207-216.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

In the first stage of PLA degradation, random non-enzymatic chain scission of the ester groups leads to a reduction in Mw.

“First, random non-enzymatic chain scission of the ester groups leads to a reduction in Mw.”

• cites [17] 17. R. Auras, B. Harte, S. Selke, Macromol. Biosci. 4 (2004) 835-864.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [30] 30. H.T. Oyama, Y. Tanaka, A. Kadosaka, Polym. Degrad. Stab. 94 (2009) 1419-1426.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The melting temperature (Tm) and the glass transition temperature (Tg) of PLA decrease with decreasing amounts of PLLA.

“The melting temperature (T m ), and the glass transition temperature (T g ) of PLA decrease with decreasing amounts of PLLA [7].”

• cites [7] 7. R. Auras, L.T. Lim, S.E.M. Selke, H. Tsuji, New Jersey: Jhon Wiley & Sons, Inc., 2010.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA properties may be controlled through the use of special catalysts of isotactic and syndiotactic content with different enantiometric units.

“PLA properties may be controlled through the use of special catalysts of isotactic and syndiotactic content with different enantiometric units [16].”

• cites [16] 16. B. Gupta, N. Revagade, J. Hilborn, Prog. Polym. Sci. 32 (2007) 455-482.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

By modification of the chain architecture through the introduction of branching, different melt flow properties will be obtained.

“By modification of the chain architecture through the introduction of branching, different melt flow properties will be obtained [1].”

• cites [1] 1. M. Savioli Lopes, A.L. Jardini, R. Maciel Filho, Procedia Eng. 42 (2012) 1402-1413.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Any factor which affects the reactivity and the accessibility, such as particle size and shape, temperature, moisture, crystallinity, % isomer, residual lactic acid concentration, Mw, water diffusion and metal impurities from the catalyst, will affect the polymer degradation rate.

“Any factor which affects the reactivity and the accessibility, such as particle size and shape, temperature, moisture, crystallinity, % isomer, residual lactic acid concentration, Mw, water diffusion and metal impurities from the catalyst, will affect the polymer degradation rate [2,17,[31][32][33].”

• cites [2,17,[31][32][33]Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

This particular functionalized PLA has a favorable biodegradation rate.

“This particular functionalized PLA has a favorable biodegradation rate [37].”

• cites [37] 37. E. Jabbari, X. He, J. Mater. Sci. Mater. Med. 19 (2008) 311-318.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Longer relaxation times in the terminal region of the branched material introduced it as a higher zero shear rate viscosity.

“Longer relaxation times in the terminal region of the branched material introduced it as a higher zero shear rate viscosity.”

• cites [38] 38. J.R. Dorgan, H. Lehermeier, M. Mang, J. Polym. Environ. 8 (2000) 1-9.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

By utilizing the structure modifications through polymer branching the ability of using PLA in many processing operations will be extended.

“They concluded that by utilizing the structure modifications through polymer branching the ability of using PLA in many processing operations will be extended.”

Changes in Mn of PLA films in the range of 9 × 10^4 to 5 × 10^5 g/mol and D-lactide unit content of PLA films in the range of 0% to 50% have insignificant effects on their WVTR values.

“They also concluded that changes in Mn of PLA films in the range of 9 × 10 4 to 5 × 10 5 g/mol and D-lactide unit content of PLA films in the range of 0% to 50% have insignificant effects on their WVTR values [3,46].”

• cites [3] 3. M. Jamshidian, E. Arab-Tehrany, M. Imran, M. Jacquot, S. Desobry, Compr. Rev. Food Sci. Food Saf. 9 (2010) 552-571.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [46] 46. H. Tsuji, R. Okino, H. Daimon, K. Fujie, J. Appl. Polym. Sci. 99 (2006) 2245-2252.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

This prolonged existence in vivo in some organs may lead to inflammation and infection.

“This prolonged existence in vivo in some organs may lead to inflammation and infection [35].”

• cites [35] 35. J.E. Bergsma, W.C. De Bruijn, F.R. Rozema, R.R.M. Bos, G. Boering, Biomaterials 16 (1995) 25-31.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Below the β-transition temperature of approximately -45 °C, PLA will only behave as a brittle polymer.

“Below this temperature PLA will only behave as a brittle polymer [8].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Tensile modulus of PLLA increases by a factor of 2 when the Mw is raised from 50 to 100 kDa.

“For example, it has been shown that tensile modulus of PLLA increases by a factor of 2 when the Mw is raised from 50 to 100 kDa [10], and tensile strengths of 15.5, 80 and 150 MPa, for varying the Mw from 50 over 150 to 200 kDa respectively [48].”

• cites [10] 10. Anders Sodergard, Mikael Stolt, Prog. Polym. Sci. 27 (2002) 1123-1163.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

By utilizing stereoselective catalysts in the polymerization, semicrystalline polymers have been prepared both from meso-lactide and rac-lactide.

“By utilizing stereoselective catalysts in the polymerization, semicrystalline polymers have been prepared both from meso-lactide [70] and rac-lactide [71,72].”

• cites [70] 70. T.M. Ovitt, G.W. Coates, J. Am. Chem. Soc. 121 (1999) 4072-4073.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [71] 71. C.P. Radano, G.L. Baker, M.R. Smith, J. Am. Chem. Soc. 122 (2000) 1552-1553. sourceNot checked — no full text of the source
• cites [72] 72. T.M. Ovitt, G.W. Coates, J. Polym. Sci. Part A: Polym. Chem. 38 (2000) 4686-4692.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Tensile strengths of 15.5, 80 and 150 MPa were observed for varying the Mw from 50 over 150 to 200 kDa respectively.

“For example, it has been shown that tensile modulus of PLLA increases by a factor of 2 when the Mw is raised from 50 to 100 kDa [10], and tensile strengths of 15.5, 80 and 150 MPa, for varying the Mw from 50 over 150 to 200 kDa respectively [48].”

• cites [48] 48. K. Van de Velde, P. Kiekens, Polym. Test. 21 (2002) 433-442.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The ability to control the stereochemical architecture allows precise control over the speed and degree of crystallinity, the mechanical properties, and the processing temperatures of the material.

“The ability to control the stereochemical architecture allows precise control over the speed and degree of crystallinity, the mechanical properties, and the processing temperatures of the material.”

Tensile properties are clearly best for the densest reported polymers, especially for poly(glycolic acid) (PGA).

“It has been found that tensile properties are clearly best for the densest reported polymers, especially for poly(glycolic acid) (PGA).”

• cites [48] 48. K. Van de Velde, P. Kiekens, Polym. Test. 21 (2002) 433-442.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

This has been noticed for PLAs prepared by both polycondensation and ring-opening polymerization.

“This has been noticed for PLAs prepared by both polycondensation and ring-opening polymerization [83].”

• cites [83] 83. I. Ajioka, K. Enomoto, K. Suzuki, A. Yamaguchi, J. Environ. Polym. Degrad. 3 (1995) 225-234.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The mechanical properties of polymers of similar Mw, but prepared by different polymerization processes, have been shown not to differ.

“It should be emphasized that the mechanical properties of polymers of similar Mw, but prepared by different polymerization processes, have been shown not to differ.”

• cites [83] 83. I. Ajioka, K. Enomoto, K. Suzuki, A. Yamaguchi, J. Environ. Polym. Degrad. 3 (1995) 225-234.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The rac-PLA prepared by using a racemic aluminum alkoxide catalyst was reported to have a Tm of 191 °C with a ΔH of 42 J/g.

“The rac-PLA prepared by using a racemic aluminum alkoxide catalyst was reported to have a T m of 191 °C with a ΔH of 42 J/g [71].”

• cites [71] 71. C.P. Radano, G.L. Baker, M.R. Smith, J. Am. Chem. Soc. 122 (2000) 1552-1553. sourceNot checked — no full text of the source

Variations such as block and star copolymers of D- and L-lactide show this same stereocomplexation.

“Variations such as block and star copolymers of D-and L-lactide show this same stereocomplexation [77].”

• cites [77] 77. M.H. Hartmann, in: D.L. Kaplan (Ed.), Biopolymers From Renewable Resources, Springer-Verlag, Berlin 1998, pp. 367-411. sourceNot checked — no full text of the source

The mechanical properties and crystallization behavior of PLA are very dependent on the Mw and stereo chemical makeup of the backbone.

“Different from thermal properties, the mechanical properties and crystallization behavior of PLA are very dependent on the Mw and stereo chemical makeup of the backbone [5].”

• cites [5] 5. D. Garlotta, J. Polym. Environ. 9 (2002) 63-84.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The high Tm was believed to be the result from co-crystallization of enantiomerically pure D- and L-PLA leading to a stereocomplex formation.

“The high T m was believed to be the result from co-crystallization of enantiomerically pure D-and L-PLA leading to a stereocomplex formation.”

These temperatures for PLA are ranging from 190 to 250 °C.

“These temperatures for PLA are ranging from 190 to 250 °C [49,51,52,[55][56][57][58].”

• cites [49,51,52,[55][56][57][58]Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA degradation is dependent on time, temperature, low-Mw impurities, and catalyst concentration.

“PLA degradation is dependent on time, temperature, low-Mw impurities, and catalyst concentration [5].”

• cites [5] 5. D. Garlotta, J. Polym. Environ. 9 (2002) 63-84.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

A 1:1 mixture of pure PLLA with pure PDLA will yield an insoluble gel formed by the stereocomplexation (racemic crystallite) of the two polymers during crystallization or polymerization.

“It has also been observed that a 1:1 mixture of pure PLLA with pure PDLA will yield an insoluble gel formed by the stereocomplexation (racemic crystallite) of the two polymers during crystallization or polymerization [75,76].”

• cites [75] 75. H. Yamane, K. Sasai, Polymer 44 (2003) 2569-2575.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [76] 76. Y. Furuhashi, Y. Kimura, N. Yoshie, H. Yamane, Polymer 47 (2006) 5965-5972.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

An optical purity of at least 72-75%, corresponding to about 30 isotactic lactyl units, is required for the crystallization to take place.

“It has been observed that an optical purity of at least 72-75%, corresponding to about 30 isotactic lactyl units, is required for the crystallization to take place [66].”

• cites [66] 66. J. Huang, M.S. Lisowski, J. Runt, E.S. Hall, R.T. Kean, N. Buehler, J.S. Lin, Macromole- cules 31 (1998) 2593-2599.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The increase in elongation at break of extruded/injected PLA materials is attributed to a higher number of chains due to chain scissions in reprocessed materials.

“It is attributed to a higher number of chains, due to chain scissions in reprocessed materials, Table 6.”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The increase in Young's modulus and yield strength after annealing is explained by the higher degree of crystallinity of annealed materials, with its subsequent decrease in chain mobility.

“After annealing, samples showed an increase in Young's modulus (5-11%) and in yield strength (15-18%), which is explained by the higher degree of crystallinity of annealed materials, with its subsequent decrease in chain mobility.”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Different factors like particle/device size and polymer shape, temperature, moisture, crystallinity, % D-isomer, residual lactic acid concentration, Mw and its distribution, water diffusion, and metal impurities from the catalyst will affect the polymer degradation rate.

“Different factors like particle/device size and polymer shape, temperature, moisture, crystallinity, % D-isomer, residual lactic acid concentration, Mw and its distribution, water diffusion, and metal impurities from the catalyst will affect the polymer degradation rate [3].”

• cites [3] 3. M. Jamshidian, E. Arab-Tehrany, M. Imran, M. Jacquot, S. Desobry, Compr. Rev. Food Sci. Food Saf. 9 (2010) 552-571.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

For injection molding of PLA, a Mw decrease of 14-40% was reported.

“For the case of injection molding of PLA a Mw decrease of 14-40% was reported [78].”

• cites [78] 78. G. Perego, G.D. Cella, C. Bastioli, J. Appl. Polym. Sci. 59 (1996) 37-43.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Intermolecular transesterification during PLA melt degradation can be minimized by the addition of benzoyl peroxide, 1,4-dianthraquinone and other stabilizers.

“Only a few studies considered the intermolecular transesterification [149,150] as a mechanism present during degradation in the melt, which can be minimized by the addition of benzoyl peroxide [151], 1,4-dianthraquinone [152] and other stabilizers.”

• cites [151] 151. A. Södergard, J.H. Näsman, Polym. Degrad. Stab. 46 (1994) 25-30.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [152] 152. I.C. McNeill, H.A. Leiper, Polym. Degrad. Stab. 11 (1985) 309-326.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA homopolymers require processing temperatures in excess of 185-190 °C.

“They require processing temperatures in excess of 185-190 °C [139].”

• cites [139] 139. M. Spinu, C. Jackson, M.Y. Keating, K.H. Gardner, J. Macromol. Sci., Pure Appl. Chem. A33 (1996) 1497-1530.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Fast cooling after injection molding did not allow PLA polymer chains to rearrange into a crystalline structure.

“They found that fast cooling after injection molding did not allow the polymer chains to rearrange into a crystalline structure.”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Tm depression by random incorporation of D-lactide into L-lactide to obtain PDLLA is accompanied by a significant decrease in crystallinity and crystallization rates.

“On the other hand, unfortunately, the T m depression is accompanied by a significant decrease in crystallinity and crystallization rates [139].”

• cites [139] 139. M. Spinu, C. Jackson, M.Y. Keating, K.H. Gardner, J. Macromol. Sci., Pure Appl. Chem. A33 (1996) 1497-1530.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA thermo-mechanical recycling generally causes a slight decrease of its mechanical properties after several injections or molding processes according to the nature of the polymer.

“The general trend is a slight decrease of its mechanical properties after several injections or molding processes according to the nature of the polymer [140].”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA homopolymers have a very narrow processing window.

“Consequently, PLA homopolymers have a very narrow processing window.”

The ester linkages of PLA tend to degrade during thermal processing or under hydrolytic conditions.

“The ester linkages of PLA tend to degrade during thermal processing or under hydrolytic conditions [143].”

• cites [143] 143. V. Taubner, R. Shishoo, J. Appl. Polym. Sci. 79 (2001) 2128-2135.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Processing of PLA by industrial thermoplastic processing methods is responsible for a decrease in Mw due to chain scission.

“They found that processing of PLA was responsible for a decrease in Mw, as determined by GPC, due to chain scission.”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

After annealing, an important crystalline structure was created in PLA.

“On the contrary, after annealing, an important crystalline structure was created.”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The formation of acetaldehyde is expected to increase with increasing process temperature due to the increased rate of the degradation reactions.

“The formation of acetaldehyde is expected to increase with increasing process temperature due to the increased rate of the degradation reactions.”

PLA quickly loses its thermal stability when heated above its Tm.

“PLA quickly loses its thermal stability when heated above its T m .”

• cites [141] 141. D.M. Bigg, In Society of Plastics Engineers-Annual Technical Conference, 541996 2028-2039.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The most widely used method for improving PLA processability is based on Tm depression by the random incorporation of small amounts of lactide enantiomers of opposite configuration into the polymer.

“The most widely used method for improving PLA processability is based on T m depression by the random incorporation of small amounts of lactide enantiomers of opposite configuration into the polymer (i.e., adding a small amount of D-lactide to the L-lactide to obtain PDLLA).”

A significant level of molecular degradation occurred when PLA was held 10 °C above its Tm (~160 °C) for a sustained period of time.

“A significant level of molecular degradation occurred when PLA was held 10 °C above its T m (~160 °C) for a sustained period of time, Fig. 4.”

• cites [141] 141. D.M. Bigg, In Society of Plastics Engineers-Annual Technical Conference, 541996 2028-2039.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA radical degradation only needs be taken into consideration at temperatures above 250 °C.

“PLA radical degradation only needs be taken into consideration at temperatures above 250 °C.”

• cites [153] 153. F.D. Kopinke, M. Remmler, K. Mackenzie, M. Moder, O. Wachsen, Polym. Degrad. Stab. 53 (1996) 329-342.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The degradation of PLA during the melt is mainly caused by intramolecular transesterification reactions leading to cyclic oligomers of lactic acid and lactide.

“The degradation of PLA during the melt is mainly caused by intramolecular transesterification reactions leading to cyclic oligomers of lactic acid and lactide.”

Oxidation of PLA did not occur to a measurable extent during thermal degradation.

“Oxidation of PLA didn't occur to a measurable extent during thermal degradation [142].”

• cites [142] 142. C. Migliaresi, D. Cohn, A. DeLollis, L. Fambri, J. Appl. Polym. Sci. 43 (1991) 83-95. sourceNot checked — no full text of the source

In the case of intermolecular transesterification, a reaction between two ester molecules exchanges their radicals, leading to a variation of the distribution of Mws.

“In the case of intermolecular transesterification, a reaction between two ester molecules exchanges their radicals, thus leading to a variation of the distribution of Mws [140].”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Pyrolytic elimination is a less important side reaction in PLA degradation.

“This is a less important side reaction [140].”

• cites [140] 140. F. Carrasco, P. Pagès, J. Gámez-Pérez, O.O. Santana, M.L. Maspoch, Polym. Degrad. Stab. 95 (2010) 116-125.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The primary mechanism of PLA degradation occurs by a two-step process starting with hydrolysis, followed by bacterial attack on the fragmented residues.

“The primary mechanism of degradation occurs by a twostep process starting also with hydrolysis, followed by bacterial attack on the fragmented residues.”

Stereochemistry, crystallinity, Mw, and applied loads are the main factors influencing the rate of degradation of PLA.

“However stereochemistry, crystallinity, Mw, and applied loads are the main factors influencing the rate of degradation of PLA [163].”

• cites [163] 163. Z. Zhou, J. Zhou, Q. Yi, L. Liu, Y. Zhao, H. Nie, Polym. Bull. 65 (2010) 411-423.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Only the tensile modulus of PLA remains constant with thermo-mechanical cycles up to 7 cycles.

“They found that only the tensile modulus remains constant with the thermo-mechanical cycles.”

• cites [155] 155. I. Pillin, N. Montrelay, A. Bourmaud, Y. Grohens, Polym. Degrad. Stab. 93 (2008) 321-328.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA degradation upon disposal in the environment is more challenging because PLA is largely resistant to attack by microorganisms in soil or sewage under ambient conditions.

“On the other hand, PLA degradation upon disposal in the environment (environmental degradation) is more challenging because PLA is largely resistant to attack by microorganisms in soil or sewage under ambient conditions.”

The addition of stabilizers suppresses crystallization during cooling of reprocessed PLA.

“The addition of stabilizers suppresses this crystallization during cooling.”

• cites [155] 155. I. Pillin, N. Montrelay, A. Bourmaud, Y. Grohens, Polym. Degrad. Stab. 93 (2008) 321-328.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

In the interior of a large implant, the inability of large polymeric degradation products to diffuse away results in a local acidic environment.

“In the interior of the device the inability of large polymeric degradation products to diffuse away from the bulk device results in a local acidic environment in the interior of the implant.”

• cites [62] 62. J.C. Middleton, A.J. Tipton, Biomaterials 21 (2000) 2335-2346.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The increased acidic environment catalyzes further degradation resulting in accelerated hydrolysis of the ester linkages in the interior.

“The increased acidic environment catalyzes further degradation resulting in accelerated hydrolysis of the ester linkages in the interior.”

• cites [62] 62. J.C. Middleton, A.J. Tipton, Biomaterials 21 (2000) 2335-2346.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The degradation-absorption mechanism of PLA is the result of many interrelated factors, including chemical stability of the polymer backbone, presence of catalysts, additives, impurities or plasticizers, and geometry and location of the device.

“The degradation-absorption mechanism is the result of many interrelated factors, including 1) the chemical stability of the polymer backbone, 2) the presence of catalysts, 3) additives, impurities or plasticizers, 4) the geometry and location of the device.”

• cites [62] 62. J.C. Middleton, A.J. Tipton, Biomaterials 21 (2000) 2335-2346.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLLA stent or fibers exposed to in vivo conditions do not begin to degrade until after approximately 12 months.

“PLA has a relatively long half-life of hydrolysis due to steric effects where the alkyl group hinders the attack by water, for example, PLLA stent or fibers exposed to in vivo conditions do not begin to degrade until after approximately 12 months [158,159].”

• cites [158] 158. J.S. Bergstrom, In: ANTEC, Cincinnati, OH, 2013.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [159] 159. P. Pan, Z. Liang, B. Zhu, T. Dong, Y. Inoue, Macromolecules 41 (2008) 8011-8019.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The location of the device can play an important role in the degradation rate of implants.

“The location of the device can play an important role in the degradation rate of implants.”

Lactide commercially available devices and sutures degrade by bulk erosion.

“Lactide commercially available devices and sutures degrade by bulk erosion [166].”

• cites [166] 166. K.A. Athanasiou, J.B. Schmitz, C.M. Agrawal, Tissue Eng. 4 (1998) 53-63.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The rate of degradation of PLA is also dependent on the magnitude of the applied stress.

“It has recently been shown that the rate of degradation is also dependent on the magnitude of the applied stress [165].”

• Also stated in: § Table 15 · plain

  “It has recently been shown that the rate of degradation is also dependent on the magnitude of the applied stress [165].”

• cites [165] 165. J. Kohn, R. Langer, in: B.D. Ratner, A.S. Homan, F.J. Schoen, J.E. Lemons (Eds.), Biomaterials Science, Academic Press, New York 1996, pp. 64-72.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA has a relatively long half-life of hydrolysis due to steric effects where the alkyl group hinders the attack by water.

“PLA has a relatively long half-life of hydrolysis due to steric effects where the alkyl group hinders the attack by water, for example, PLLA stent or fibers exposed to in vivo conditions do not begin to degrade until after approximately 12 months [158,159].”

• cites [158] 158. J.S. Bergstrom, In: ANTEC, Cincinnati, OH, 2013.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [159] 159. P. Pan, Z. Liang, B. Zhu, T. Dong, Y. Inoue, Macromolecules 41 (2008) 8011-8019.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA degradation is dependent on a range of factors, such as Mw, crystallinity, purity, temperature, pH, presence of terminal carboxyl or hydroxyl groups, water permeability, and additives acting catalytically that may include enzymes, bacteria or inorganic fillers.

“PLA degradation has been found to be dependent on a range of factors, such as Mw, crystallinity, purity, temperature, pH, presence of terminal carboxyl or hydroxyl groups, water permeability, and additives acting catalytically that may include enzymes, bacteria or inorganic fillers [161].”

• cites [161] 161. K.I. Park, M.A. Xanthos, Polym. Degrad. Stab. 94 (2009) 834-844.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The rate of hydrolytic degradation of PLA is primarily temperature- and humidity-dependent.

“The rate of this hydrolytic degradation is primarily temperature-and humidity-dependent.”

• cites [12] 12. J. Lunt, Polym. Degrad. Stab. 59 (1998) 145-152.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Reprocessing of PLA induces an increase of crystallization during cooling with the number of injection cycles.

“Reprocessing of PLA induces an increase of crystallization during cooling with the number of injection cycles.”

• cites [155] 155. I. Pillin, N. Montrelay, A. Bourmaud, Y. Grohens, Polym. Degrad. Stab. 93 (2008) 321-328.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Low-porosity implants from 50/50 PDLLG degrade faster than high-porosity implants.

“Athanasiou and coworkers [167] showed that low-porosity implants from 50/50 PDLLG degrade faster than high-porosity implants.”

• cites [167] 167. S. Lee, S.H. Kim, Y. Han, Y. Kim, J. Polym. Sci., Part A: Polym. Chem. 39 (2001) 973-985. sourceNot checked — no full text of the source

The polymer must first be hydrolyzed at elevated temperatures (about 60 °C) to reduce the Mw before biodegradation can commence.

“The polymer must first be hydrolyzed at elevated temperatures (about 60 °C) to reduce the Mw before biodegradation can commence.”

Free radical stabilizer (i.e. Quinone) was found to be an efficient stabilizer to trap free radicals and maintain PLA chain length with time at the processing temperatures.

“1) free radicals stabilizer (i.e.Quinone) [155], was found to be an efficient stabilizer to trap free radicals and maintain PLA chain length with time at the processing temperatures.”

• cites [155] 155. I. Pillin, N. Montrelay, A. Bourmaud, Y. Grohens, Polym. Degrad. Stab. 93 (2008) 321-328.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

As the average Mw reaches approximately ~10,000 Da, micro-organisms present in the soil begin to digest the lower Mw lactic acid oligomers, producing carbon dioxide and water.

“As the average Mw reaches approximately ~10,000 Da, micro-organisms present in the soil begin to digest the lower Mw lactic acid oligomers, producing carbon dioxide and water (Fig. 7B) [12].”

• cites [12] 12. J. Lunt, Polym. Degrad. Stab. 59 (1998) 145-152.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The reduction in Mw is soon followed by a reduction in physical properties as water begins to fragment the device.

“The reduction in Mw is soon followed by a reduction in physical properties as water begins to fragment the device [62].”

• cites [62] 62. J.C. Middleton, A.J. Tipton, Biomaterials 21 (2000) 2335-2346.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Cleavage of the ester linkages by absorbed water produces a successive reduction in Mw.

“As illustrated in Fig. 7A, cleavage of the ester linkages by absorbed water produces a successive reduction in Mw.”

PLA products rapidly degrade in both aerobic and anaerobic composting conditions.

“PLA products rapidly degrade in both aerobic and anaerobic composting conditions [8].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

In the second phase of semi-crystalline PLA biodegradation, enzymatic attack of the fragments occurs.

“In the second phase, enzymatic attack of the fragments occurs.”

• cites [62] 62. J.C. Middleton, A.J. Tipton, Biomaterials 21 (2000) 2335-2346.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Under conditions of high temperature and high humidity, as in active compost, PLA will degrade quickly and disintegrate within weeks to months.

“Under conditions of high temperature and high humidity, as in active compost, for example, PLA will degrade quickly and disintegrate within weeks to months [8].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Semi-crystalline PLA biodegradation occurs in two phases.

“However semi-crystalline PLA biodegradation occurs in two phases.”

• cites [62] 62. J.C. Middleton, A.J. Tipton, Biomaterials 21 (2000) 2335-2346.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The metabolizing of the fragments results in a rapid loss of polymer mass.

“The metabolizing of the fragments results in a rapid loss of polymer mass (illustrated by Fig. 8) [62].”

• cites [62] 62. J.C. Middleton, A.J. Tipton, Biomaterials 21 (2000) 2335-2346.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

With natural fibers as reinforcement, end-of-life composting of PLA biocomposites is possible.

“Furthermore, with natural fibers as reinforcement end-of-life composting is possible.”

Implants under stress degrade faster.

“Implants under stress degrade faster.”

• cites [165] 165. J. Kohn, R. Langer, in: B.D. Ratner, A.S. Homan, F.J. Schoen, J.E. Lemons (Eds.), Biomaterials Science, Academic Press, New York 1996, pp. 64-72.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA performance in terms of durability is limited by multiple chemical aging mechanisms such as thermal decomposition, hydrolysis, photo-oxidation, natural weathering and thermo oxidation at high temperature.

“PLA performance in terms of durability are limited by multiple chemical aging mechanisms such as thermal decomposition [207,208], hydrolysis [209,210], photo-oxidation [211,212], natural weathering [213] and thermo oxidation at high temperature [214,215].”

• cites [207] 207. O. Wachsen, K. Platkowski, K.H. Reichert, Polym. Degrad. Stab. 57 (1997) 87-94.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [208] 208. S. Li, S. McCarthy, Biomaterials 20 (1999) 35-44. sourceNot checked — no full text of the source
• cites [209] 209. X. Zhang, M. Espiritu, A. Bilyk, L. Kurniawan, Polym. Degrad. Stab. 93 (2008) 1964-1970.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [210] 210. A. Copinet, C. Bertrand, S. Govindin, V. Coma, Y. Couturier, Chemosphere 55 (2004) 763-773.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [211] 211. H. Tsuji, Y. Echizen, Y. Nishimura, Polym. Degrad. Stab. 91 (2006) 1128-1137.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [212] 212. L. Zaidi, M. Kaci, S. Bruzaud, A. Bourmaud, Y. Grohens, Polym. Degrad. Stab. 95 (2010) 1751-1758.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Certain impurities and classes of additives increase the rate of PLA hydrolysis, including lactide and oligomers and some acidic and basic additives.

“Certain impurities and classes of additives increase the rate of PLA hydrolysis, including lactide and oligomers and some acidic and basic additives.”

In an early study examining the effects of 7 different steam sterilization techniques on PLLA, all evaluated techniques significantly changed at least one material property of the polymer.

“In an early study examining the effects of 7 different steam sterilization techniques on PLLA, it was determined that all the evaluated techniques significantly changed at least one material property of the polymer.”

• cites [206] 206. Y. Aoyagi, K. Yamashita, Y. Doi, Polym. Degrad. Stab. 76 (2002) 53-59.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The specific effects of different sterilization techniques are determined by the sterilization parameters, the method used for fabrication, as well as the polymeric composition itself.

“For summary, the specific effects of different techniques are determined by the sterilization parameters, the method used for fabrication, as well as the polymeric composition itself.”

The use of biodegradable films for packaging applications has been strongly limited because of the poor barrier properties and weak mechanical properties shown by natural polymers.

“Unfortunately, so far the use of biodegradable films for packaging applications has been strongly limited because of the poor barrier properties and weak mechanical properties shown by natural polymers.”

• cites [170] 170. A. Sorrentino, G. Gorrasi, V. Vittoria, Trends Food Sci. Technol. 18 (2007) 84-95.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Oxidation affects the physical and mechanical properties of the polymer.

“Oxidation affects the physical and mechanical properties of the polymer.”

PLA is rigid and brittle at room temperature due to its glass transition temperature of about 55 °C.

“PLA is characterized by excellent optical properties and high tensile strength but unfortunately, it is rigid and brittle at room temperature (RT) due to its T g ~55 °C [138].”

• cites [138] 138. L.T. Lim, R. Auras, M. Rubino, Prog. Polym. Sci. 33 (2008) 820-852.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

During hydrothermal aging of PLLA, the Mw reduction is greater when the temperature and water uptake increase.

“During hydrothermal aging of PLLA the Mw reduction is greater when the temperature and water uptake increase.”

• cites [219] 219. D. Rasselet, A. Ruellan, A. Guinault, G. Miquelard-Garnier, C. Sollogoub, B. Fayolle, Eur. Polym. J. 50 (2014) 109-116.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Reduction in the rate of autocatalysis has been accomplished by incorporation of basic, buffering salts such as CaCO3.

“Reduction in the rate of autocatalysis has been accomplished by incorporation of basic, buffering salts such as CaCO 3 [8].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

At temperatures higher than 100 °C in air, the aging mechanism of PLA is undoubtedly oxidation.

“At temperatures higher than 100 °C in air, aging mechanism is undoubtedly oxidation.”

• cites [220] 220. N.S. Anderson, K.M. Schreck, M.A. Hillmyer, Polym. Rev. 48 (2008) 85-108.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Bulk hydrolysis occurs faster than surface hydrolysis.

“Bulk hydrolysis occurs faster than surface hydrolysis.”

For radiation sterilization of bioresorbable polymers, temperature and dose conditions need to be closely controlled to avoid chain scission and significant degradation.

“For radiation sterilization of bioresorbable polymers, temperature and dose conditions need to be closely controlled to avoid chain scission and significant degradation.”

• cites [4] 4. Handbook of Polymer Applications in Medicine and Medical DevicesPublished by Elsevier Inc.©, 2014, http://dx.doi.org/10.1016/B978-0-323-22805-3.00003-7. sourceNot checked — no full text of the source

By comparing aging in air and in water at 70 °C, the authors concluded that hydrolysis aging can be neglected in air.

“By comparing aging in air and in water at 70 °C, the authors concluded that the hydrolysis aging can be neglected in air.”

• cites [220] 220. N.S. Anderson, K.M. Schreck, M.A. Hillmyer, Polym. Rev. 48 (2008) 85-108.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The rate of Mw loss, tensile strength, Young's modulus, melting temperature, and mass remaining of the films in the course of hydrolysis was more stable for the stereocomplex film than for the nonblended films.

“They found that the rate of Mw loss, tensile strength, Young's modulus, melting temperature, and mass remaining of the films in the course of hydrolysis was more stable for the stereocomplex film than for the nonblended films [169].”

• cites [169] 169. G. Mensitieri, E. Di Maio, G.G. Buonocore, I. Nedi, M. Oliviero, L. Sansone, S. Iannace, Trends Food Sci. Technol. 22 (2011) 72-80.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA first degrades in the more loosely packed chain folding regions.

“PLA first degrades in the more loosely packed chain folding regions.”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

NH2- and Cl-terminated PLAs were more resistant to thermal and hydrolytic degradation.

“NH 2 -and Cl-terminated PLAs were more resistant to thermal and hydrolytic degradation.”

• cites [168] 168. H. Tsuji, M. Suzuki, Sen'i Gakkaishi 57 (2001) 198-202.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The thermal oxidation mechanism of PLA at low temperatures (T < 160 °C) leads to a random chain scission process, responsible for the decrease of the PLA Mw as found by SEC measurements.

“They also concluded that the thermal oxidation mechanism of PLA at low temperatures (T b 160 °C) leads to a random chain scission process, responsible for the decrease of the PLA Mw as found by SEC measurements.”

• cites [220] 220. N.S. Anderson, K.M. Schreck, M.A. Hillmyer, Polym. Rev. 48 (2008) 85-108.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Detrimental effects of chemical sterilization on the mechanical properties of PLA based polymers have rarely been reported in the literature.

“However, detrimental effects of chemical sterilization on the mechanical properties of the PLA based polymers have rarely been reported in the literature.”

• cites [203] 203. W. Michaeli, R. Von Oepen, ANTEC, 1994 796-804.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Chemical sterilization by gases such as ethylene oxide (EO) is often used for polymers that are sensitive to heat and moisture such as PLA based polymers.

“Chemical sterilization by gases such as ethylene oxide (EO) is often used for polymers that are sensitive to heat and moisture such as the case in PLA based polymers [203].”

• cites [203] 203. W. Michaeli, R. Von Oepen, ANTEC, 1994 796-804.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Gamma sterilization at dry ice temperatures is more preferred.

“Gamma sterilization at dry ice temperatures is more preferred [4].”

• cites [4] 4. Handbook of Polymer Applications in Medicine and Medical DevicesPublished by Elsevier Inc.©, 2014, http://dx.doi.org/10.1016/B978-0-323-22805-3.00003-7. sourceNot checked — no full text of the source

Hydrolysis of the crystalline domain occurs mainly by a surface erosion mechanism.

“Hydrolysis of the crystalline domain occurs mainly by a surface erosion mechanism.”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The most commonly used material for bioresorbable scaffolds/stents is PLLA.

“Accordingly, the most commonly used material for bioresorbable scaffolds/stents is PLLA [267,268].”

• cites [267] 267. C. Nakafuku, S. Takehisa, J. Appl. Polym. Sci. 93 (2004) 2164-2173.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [268] 268. L. Durselen, M. Dauner, H. Hierlemann, H. Planck, L.E. Claes, A. Ignatius, J. Biomed. Mater. Res. 58 (2001) 666-672.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

For PLA, breakage of ester bonds occurs randomly through hydrolytic ester cleavage, leading to subsequent erosion of the device.

“For PLA, the breakage of ester bonds occurred randomly through hydrolytic ester cleavage, leading to subsequent erosion of the device.”

Each biomedical application demands materials with specific physical, chemical, biological, biomechanical and degradation properties to provide efficient therapy.

“Each of these applications demands materials with specific physical, chemical, biological, biomechanical and degradation properties to provide efficient therapy [1].”

• cites [1] 1. M. Savioli Lopes, A.L. Jardini, R. Maciel Filho, Procedia Eng. 42 (2012) 1402-1413.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA is used in a wide range of biomedical applications such as stents, surgical sutures, plates and screws for craniomaxillofacial bone fixation, interference screws, tacks and pins, anchors, spinal cages, soft-tissue implants, tissue engineering scaffolds, tissue cultures, drug delivery devices, and craniofacial augmentations.

“PLA is used in a wide range of biomedical applications such as stents [250][251][252][253], surgical sutures [254], plates and screws for craniomaxillofacial bone fixation [255], interference screws in ankle, knee, and hand; tacks and pins for ligament attachment, anchors [256], spinal cages [250,257], soft-tissue implants, tissue engineering scaffolds, tissue cultures, drug delivery devices [258]”

• cites [250] 250. P. Erne, M. Schier, T.J. Resink, Cadriovasc. Intervent. Radiol. 29 (2006) 11-16.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [254] 254. J.Y. Lim, S.H. Kim, S. Lim, Y.H. Kim, Macromol. Mater. Eng. 288 (2003) 50-57.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [255] 255. L.E.S. DeJong, T.M. DeBarardino, D.E. Brooks, K. Judson, Arthroscopy 20 (2004) 511-516.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

In many cases PLA can be blended or copolymerized with other polymeric or non-polymeric components to achieve desired behavior.

“In many cases the PLA can be blended or copolymerized with other polymeric or non-polymeric components to achieve the desired behavior [16,40].”

• cites [16] 16. B. Gupta, N. Revagade, J. Hilborn, Prog. Polym. Sci. 32 (2007) 455-482.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [40] 40. Y. Cheng, S. Deng, P. Chen, R. Ruan, Front. Chem. Chin. 4 (2009) 259-264.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

An increase in crystallinity through an optimized injection molding process and addition of nucleating agents can result in direct and significant improvement in mechanical performance of a commercial grade of PLA.

“The study outcome showed for the first time that an increase in the crystallinity through an optimized injection molding process and the addition of nucleating agents can result in a direct and significant improvement in mechanical performance of a commercial grade of PLA [248].”

• cites [248] 248. S.C. Schmidt, M.A. Hillmyer, J. Polym. Sci. B Polym. Phys. 39 (2001) 300-313.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Several studies have reported a variety of physical nucleating agents for PLA, including talc and nanoclays.

“So far several studies have reported a variety of physical nucleating agents for PLA, including talc and nanoclays [127,144,179,[237][238][239][240][241][242][243][244][245][246][247].”

• cites [127] 127. S.S. Ray, K. Yamada, M. Okamoto, A. Ogami, K. Ueda, Chem. Mater. 15 (2003) 1456-1465.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [144] 144. Y. Fan, H. Nishida, Y. Shirai, T. Endo, Degrad. Stab. 84 (2004) 143-149. sourceNot checked — no full text of the source
• cites [179] 179. F. Jing, M.A. Hillmyer, J. Am. Chem. Soc. 130 (13) (2008) 826-13,827.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLAs have been utilized for continuous drug release for different periods including prolonged administration of contraceptives, narcotic antagonists, local anesthetics, vaccines, peptides and proteins.

“PLAs have been utilized for continuous drug release for different periods of time including prolonged administration of a wide variety of medical agents such as contraceptives, narcotic antagonists, local anesthetics, vaccines, peptides and proteins [270,271].”

• cites [270] 270. M.A. Valantin, C. Aubron-Olivier, J. Ghosn, E. Laglenne, M. Pauchard, H. Schoen, AIDS 17 (2003) 2471-2477.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [271] 271. J.C. Leroux, E. Allémann, F. De Jaeghere, E. Doelker, R. Gurny, J. Control. Release 39 (1996) 339-350.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Plasticization is limited by the amount of plasticizer to be blended with PLA.

“The plasticization is thus limited by the amount of plasticizer to be blended with PLA [231].”

• cites [231] 231. Y. Hu, Y.S. Hu, V. Topolkaraev, A. Hiltner, E. Baer, Polymer 44 (2003) 5711-5720.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• AssumptionRests on an assumption: Typically, 10-20% w/w amount of plasticizers is required to provide both a substantial reduction of the glass transition temperature of the PLA matrix and adequate mechanical properties.
• AssumptionRests on an assumption: Addition of more than 20-30% (depending on the plasticizer) of plasticizers into the PLA matrix leads to a phase separation that needs to be avoided.

Plasticizers with rather high molecular weight and low mobility are necessary.

“Therefore, plasticizers with rather high Mw and low mobility are necessary.”

Mechanical characteristics of PLA/plasticizer materials showed a decrease in modulus and stress at break.

“It was found that the mechanical characteristics of these materials showed a decrease in modulus and stress at break.”

• cites [155] 155. I. Pillin, N. Montrelay, A. Bourmaud, Y. Grohens, Polym. Degrad. Stab. 93 (2008) 321-328.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA can exhibit premature failure at stress magnitudes significantly lower than both the yield strength and the ultimate tensile strength due to viscoplastic flow causing creep rupture or fatigue failure.

“An additional complication is that PLA can exhibit premature failure at stress magnitudes that are significantly lower than both the yield strength and the ultimate tensile strength of the material due to viscoplastic flow causing creep rupture or fatigue failure.”

PLA blended to PEGs becomes very brittle as a function of plasticizer content and molecular weight.

“Nevertheless, the PLA blended to PEGs becomes very brittle as a function of plasticizer content and Mw.”

• cites [155] 155. I. Pillin, N. Montrelay, A. Bourmaud, Y. Grohens, Polym. Degrad. Stab. 93 (2008) 321-328.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Stereochemistry, crystallinity, molecular weight, and applied loads are the main factors influencing the rate of degradation of PLA.

“The stereochemistry, crystallinity, Mw, and applied loads are the main factors influencing the rate of degradation of PLA [163,263].”

• cites [163] 163. Z. Zhou, J. Zhou, Q. Yi, L. Liu, Y. Zhao, H. Nie, Polym. Bull. 65 (2010) 411-423.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [263] 263. D. Grijpma, A.J. Pennings, Macromol. Chem. Phys. 195 (1994) 1649-1663.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The challenge of controlled drug release can be tuned by mechanical stability and crystallinity degree of PLA in the formulation.

“It has been found that the challenge of controlled drug release can be tuned by mechanical stability and crystallinity degree of PLA in the formulation [44].”

• cites [44] 44. K. Hamad, M. Kaseem, H.W. Yang, F. Deri, Y.G. Ko1, Express Polym Lett 9 (2015) 435-455.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Isothermal crystallization halftimes decreased nearly 65-fold by addition of just 2% talc.

“Isothermal crystallization halftimes were found to decrease nearly 65-fold by the addition of just 2% talc.”

• cites [248] 248. S.C. Schmidt, M.A. Hillmyer, J. Polym. Sci. B Polym. Phys. 39 (2001) 300-313.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Low molecular weight plasticizers have a migration problem due to their high mobility within the PLA matrix.

“However, the low Mw plasticizers have the problem of migrating, owing to their high mobility within the PLA matrix.”

Thermoformed PLA containers are used in retail markets for fruits, vegetables, and salads.

“New applications have been claimed in the field of fresh products, where thermoformed PLA containers are used in retail markets for fruits, vegetables, and salads.”

• cites [160] 160. K.M. Nampoothiri, N.R. Nair, R.P. John, Bioresour. Technol. 101 (2010) 8493-8501.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The major PLA application is in packaging (nearly 70%).

“For today, the major PLA application is in packaging (nearly 70%), while the estimation for 2020 shows the increase of other applications especially in fibers and fabrics (up to 50%) [3].”

• cites [3] 3. M. Jamshidian, E. Arab-Tehrany, M. Imran, M. Jacquot, S. Desobry, Compr. Rev. Food Sci. Food Saf. 9 (2010) 552-571.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA has been blended with polymers such as poly(hydroxybutyrate), poly(vinylacetate), poly(ethylene oxide) and polysaccharides.

“For food contact applications a number of plasticizers or polymers have been reported [155], PLA has been blended with polymers such as poly(hydroxybutyrate), poly(vinylacetate), poly(ethylene oxide) and polysaccharides [189,313,314].”

• cites [189] 189. T. Ke, X.S. Sun, J. Polym. Environ. 11 (2003) 7-14.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [313] 313. T. Ke, X. Sun, J. Appl. Polym. Sci. 89 (2003) 1203-1211.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [314] 314. S. Sinha Ray, M. Bousmina, Prog. Mater. Sci. 50 (2005) 962-1079.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA has inferior moisture barrier properties compared to synthetic polymers.

“Another challenge: PLA inferior moisture barrier properties compared to synthetic polymers [160].”

• cites [160] 160. K.M. Nampoothiri, N.R. Nair, R.P. John, Bioresour. Technol. 101 (2010) 8493-8501.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

These polymer blends generally exhibit phase separation in the whole or part of the composition range.

“However, these polymer blends generally exhibit phase separation in the whole or part of the composition range similar to [305]).”

• cites [305] 305. V. Senekovic, B. Poberaj, L. Kovacic, M. Mikek, E. Adar, A. Dekel, Eur. J. Orthop. Surg. Traumatol. 23 (2013) 311-316.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA brings good wickability of moisture to applications.

“PLA also burns with low smoke generation, has good ultraviolet resistance, is easily dyeable, and brings good wickability of moisture to applications [8].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

These degradable devices in comparison to their metallic counterparts were found to exhibit similar rates of success.

“These degradable devices in comparison to their metallic counterparts were found to exhibit similar rates of success [8,287,288].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [287] 287. E. Waris, N. Ashammakhi, H. Happonen, T. Raatikainen, O. Kaarela, P. Tormala, S. Santavirta, Y.T. Konttinen, Clin. Orthop. Relat. Res. 410 (2003) 310-319.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [288] 288. F.A. Barber, Orthop. Spec. Ed. 4 (1998) 1111-1117.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA has good ultraviolet resistance.

“PLA also burns with low smoke generation, has good ultraviolet resistance, is easily dyeable, and brings good wickability of moisture to applications [8].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

A PLA-based material having good stiffness-toughness balance along with high biobased PLA content is still elusive.

“So, a PLA based material having good stiffness-toughness balance along with high biobased PLA content is still elusive [160].”

• cites [160] 160. K.M. Nampoothiri, N.R. Nair, R.P. John, Bioresour. Technol. 101 (2010) 8493-8501.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Films are the second largest application area for PLA.

“Films are the second largest application area for PLA.”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The biodegradation rate of a biopolymer depends mainly on its intrinsic properties, including chemical structure, presence of hydrolytically unstable bonds, level of hydrophilicity/hydrophobicity, crystalline/amorphous morphology, glass transition temperature, copolymer ratio, and molecular weight.

“The biodegradation rate of a biopolymer depends mainly on its intrinsic properties, including, chemical structure, the presence of hydrolytically unstable bonds, level of hydrophilicity/hydrophobicity, crystalline/amorphous morphology, T g , copolymer ratio, and its Mw [301].”

• cites [301] 301. B.C. Gross, J.L. Erkal, S.Y. Lockwood, C. Chen, D.M. Spence, Anal. Chem. 86 (2014) 3240-3253.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Implants under stress have been reported to degrade faster.

“Also implants under stress have been reported to degrade faster.”

Nanocomposites of aPLA and aPLA/PCL blends obtained by melt-mixing with modified kaolinite showed improvement in these properties with regard to polymers and blends without clay.

“for example, nanocomposites of the aPLA and aPLA/ PCL blends were obtained by melt-mixing with a properly modified kaolinite showed an improvement in these properties with regard to the polymers and blends without clay [312].”

• cites [312] 312. H. Wang, X. Sun, P. Seib, J. Appl. Polym. Sci. 90 (2003) 3683-3689.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The estimation for 2020 shows an increase of other applications, especially in fibers and fabrics (up to 50%).

“For today, the major PLA application is in packaging (nearly 70%), while the estimation for 2020 shows the increase of other applications especially in fibers and fabrics (up to 50%) [3].”

• cites [3] 3. M. Jamshidian, E. Arab-Tehrany, M. Imran, M. Jacquot, S. Desobry, Compr. Rev. Food Sci. Food Saf. 9 (2010) 552-571.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA films are transparent when stress crystallized.

“Films are transparent when stress crystallized and have acceptance by customers for food contact.”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Polymers have advantages over metal implants in that they transfer stress over time to the damaged area, allowing healing of the tissues.

“While typical devices are composed of steel or titanium to ensure that the devices are capable of withstanding in vivo loading over long periods of time [278], polymers have advantages over metal implants in that they transfer stress over time to the damaged area, allowing healing of the tissues [62].”

• cites [62] 62. J.C. Middleton, A.J. Tipton, Biomaterials 21 (2000) 2335-2346.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA burns with low smoke generation.

“PLA also burns with low smoke generation, has good ultraviolet resistance, is easily dyeable, and brings good wickability of moisture to applications [8].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA films have acceptance by customers for food contact.

“Films are transparent when stress crystallized and have acceptance by customers for food contact.”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA excels at resistance to stain in standard tests with coffee, cola, tea, catsup, lipstick, and mustard.

“PLA excels at resistance to stain in standard tests with coffee, cola, tea, catsup, lipstick, and mustard.”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA blends exhibit phase separation especially at plasticizer content above 20%.

“plasticizer usage especially at higher % (above 20%) [155].”

• cites [155] 155. I. Pillin, N. Montrelay, A. Bourmaud, Y. Grohens, Polym. Degrad. Stab. 93 (2008) 321-328.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA is easily dyeable.

“PLA also burns with low smoke generation, has good ultraviolet resistance, is easily dyeable, and brings good wickability of moisture to applications [8].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA films have superior dead fold or twist retention for twist wrap packaging.

“PLA films also have superior dead fold or twist retention for twist wrap packaging [8].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Several PLA blends based on synthetic or natural components have been reported and found very efficient in PLA properties improvement.

“recently, several PLA blends based synthetic or natural components have been reported and found very efficient in PLA properties improvement [235,[330][331][332][333][334][335][336][337][338][339][340][341][342][343].”

• cites [235] 235. O. Martin, L. Avérous, Polymer 42 (2001) 6209-6219.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [330] 330. E. Hassan, Y. Wei, H. Jiao, Y. Muhuo, J. Fiber Bioeng. Inform. 6 (2013) 85-94.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [331] 331. M.J. Liu, S.C. Chen, K.K. Yang, Y.Z. Wang, RSC Adv. 5 (2015) 42162-42173.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Investigated composites can be used for different technical applications, each suiting specific requirements.

“The results have shown so far that the investigated composites with their various characteristics can be used for different technical applications, each suiting specific requirements.”

Major antimicrobial agents for PLA include bacteriocins (predominantly nisin), lactic acid, lysozyme, and chitosan.

“In this regard, major antimicrobial agents include bacteriocins, predominantly nisin [321], lactic acid [322], lysozyme [323], and chitosan [324,325].”

• cites [321] 321. T. Ariyapitipun, A. Mustapha, A.D. Clarke, J. Food Prot. 62 (1999) 913-920.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [322] 322. M.A. Del Nobile, A. Conte, G.G. Buonocore, A.L. Incoronato, A. Massaro, O. Panza, J. Food Eng. 93 (2009) 1-6.Not matched

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• cites [323] 323. S. Torres-Giner, M.J. Ocio, J.M. Lagaron, Eng. Life Sci. 8 (2008) (2008) 303-314.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

A range of active additives have already been successfully incorporated in antimicrobial active packaging.

“A whole range of active additives, including silversubstituted zeolite, organic acids and their salts, bacteriocins such as nisin and pediocin, enzymes such as lysozyme, a chelator like ethylenediaminetetraacetic acid (EDTA), lactoferrin, and plant extracts have already been successfully incorporated in antimicrobial active packaging [319].”

• cites [319] 319. FDA, FDA/CFSAN/OPA: Agency Response Letter: GRAS Notice No. GRN 000065, 2001.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The higher biodegradation rate is attributed to high relative hydrophilicity of clays, allowing easier permeability of water into the polymer matrix and activating hydrolytic degradation.

“It was found that PLA based nanocomposites have exhibited higher rates of PLA biodegradation in compost by the addition of nanoclays, which was attributed to the high relative hydrophilicity of the clays, allowing an easier permeability of water into the polymer matrix and activating the hydrolytic degradation process [316].”

• cites [316] 316. P. Bordes, E. Pollet, L. Averous, Prog. Polym. Sci. 34 (2009) 125-155.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Active agent-loaded polymeric micro-/nanoparticles are promising formulations to achieve long-lasting antimicrobial activity as they prevent invasion of bacteria and micro-organisms.

“Active agent-loaded polymeric micro-/nanoparticles give the impression of being promising formulations to achieve long-lasting antimicrobial activity as they will prevent the invasion of bacteria and micro-organisms [329]”

• cites [329] 329. Q. Zhao, S. Wang, M. Kong, W. Geng, R.K.Y. Li, C. Song, D. Kong, J. Biomed. Mater. Res. Part B 100B (2012) 23-31.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA-based nanocomposites exhibit higher rates of PLA biodegradation in compost by addition of nanoclays.

“It was found that PLA based nanocomposites have exhibited higher rates of PLA biodegradation in compost by the addition of nanoclays, which was attributed to the high relative hydrophilicity of the clays, allowing an easier permeability of water into the polymer matrix and activating the hydrolytic degradation process [316].”

• cites [316] 316. P. Bordes, E. Pollet, L. Averous, Prog. Polym. Sci. 34 (2009) 125-155.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Thermal stability of nanocomposites is higher than that of microcomposites.

“Zhou and Xanthos studied the size effect and the kinetics of the thermal degradation of PLAs and they have concluded that, in general, the thermal stability of PDLLA and its composites is higher than that of PLLA and its composites and the thermal stability of the nanocomposites is higher than that of the microcomposites [215].”

• cites [215] 215. M.S. Islam, K.L. Pickering, N.J. Foreman, Polym. Degrad. Stab. 95 (2010) 59-65.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Many of PLA's weaknesses have been resolved.

“the linkage of a 100% bio-originated material and nanomaterials opened new windows for becoming independent from petrochemical-based polymers and many of PLA's weakness have been resolved [172,173].”

• cites [172] 172. N. Sozer, J.L. Kokini, Trends Biotechnol. 27 (2009) 82-89.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [173] 173. L.V. Labrecque, R.A. Kumar, V. Dav'e, R.A. Gross, S.P. McCarthy, J. Appl. Polym. Sci. 66 (1997) 1507-1513. sourceNot checked — no full text of the source

Linkage of a 100% bio-originated material and nanomaterials opened new windows for becoming independent from petrochemical-based polymers.

“the linkage of a 100% bio-originated material and nanomaterials opened new windows for becoming independent from petrochemical-based polymers and many of PLA's weakness have been resolved [172,173].”

• cites [172] 172. N. Sozer, J.L. Kokini, Trends Biotechnol. 27 (2009) 82-89.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [173] 173. L.V. Labrecque, R.A. Kumar, V. Dav'e, R.A. Gross, S.P. McCarthy, J. Appl. Polym. Sci. 66 (1997) 1507-1513. sourceNot checked — no full text of the source

Design of composite properties is possible by playing with different fiber characteristics.

“Playing with the different fiber characteristics a design of composite properties is possible.”

Extrusion-based processing could affect functionalities of antimicrobial compounds embedded in the polymeric matrix.

“However, the use of extrusionbased processing, industrially employed for the manufacturing of packaging films, could affect the functionalities of antimicrobial compounds embedded in the polymeric matrix [3].”

• cites [3] 3. M. Jamshidian, E. Arab-Tehrany, M. Imran, M. Jacquot, S. Desobry, Compr. Rev. Food Sci. Food Saf. 9 (2010) 552-571.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Thermal stability of PDLLA and its composites is higher than that of PLLA and its composites.

“Zhou and Xanthos studied the size effect and the kinetics of the thermal degradation of PLAs and they have concluded that, in general, the thermal stability of PDLLA and its composites is higher than that of PLLA and its composites and the thermal stability of the nanocomposites is higher than that of the microcomposites [215].”

• cites [215] 215. M.S. Islam, K.L. Pickering, N.J. Foreman, Polym. Degrad. Stab. 95 (2010) 59-65.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Various inorganic nano-particles have been recognized as possible additives to enhance polymer performance.

“Various inorganic nano-particles have been recognized as possible additives to enhance the polymer performance [171].”

• cites [171] 171. J.W. Rhim, Food Sci. Biotechnol. 16 (2007) 691-709.Not checked — no full text of the source

Fiber mixtures combine positive properties of different fibers.

“such mixtures combine the positive properties of different fibers [334][335][336][337][338][339][340][341][342][343].”

• cites [334] 334. A.K. Bledzki, A. Jaszkiewicz, D. Scherzer, Compos. Part A 40 (2009) 404-412.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [335] 335. L. Suryanegara, A.N. Nakagaito, H. Yano, Compos. Sci. Technol. 69 (2009) 1187-1192.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [336] 336. D. Shumigin, E. Tarasova, A. Krumme, P. Meier, Mater. Sci. (Medziagotyra) 17 (2011) (ISSN 1392-1320).Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

PLA can be combined with natural or regenerated fibers including cotton, wool, silk, viscose, lyocell, and others along with synthetic fibers made from PET, nylon, and other petroleum-based synthetics to improve fiber performance.

“For PLA's fiber performance improvement, it was found that it can be combined with natural or regenerated fibers including cotton, wool, silk, viscose, lyocell, and others along with synthetic fibers made from PET, nylon, and other petroleum-based synthetics [8].”

• cites [8] 8. D.E. Henton, P. Gruber, J. Lunt, J. Randall, in: A.K. Mohanty, M. Misra, L.T. Drzal (Eds.), Natural Fibers, Biopolymers, and Biocomposites, Taylor & Francis, F.L. Boca Raton 2005, pp. 527-577.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The magnitude of experimentally observed nonlinear behaviors of PLA's properties increases the importance of computational modeling.

“the magnitude of experimentally observed nonlinear behaviors of PLA's properties increases the importance of computational modeling to both understand how a device-based lactic acid will behave in a given environment, and to optimize the device for a given application.”