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Cited by 159Polymer crystallization and propertiesbiodegradable polymer synthesis and propertiesBlock Copolymer Self-Assembly

Uncompatibilized PBAT/PLA Blends: Manufacturability, Miscibility and Properties

Open access
Su, Shen, Duhme, Mona, Kopitzky, Rodion·2020·Materials
DOI 10.3390/ma13214897PMC PMC7662590
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Abstract

Polymer blends of poly(butylene adipate-co-terephthalate) (PBAT) and polylactide (PLA) have been drawn attention due to the application potential as packaging or agricultural films. This study aims to determine the manufacturability, miscibility and mechanical properties of uncompatibilized PBAT/PLA blends prepared using different techniques. First, PBAT and PLA are melt-blended in a wide range of ratios from 90/10 to 10/90. The compounds are then processed into pressed panels, flat films and blown films. Finally, the thermal, morphological, rheological and mechanical properties of these blends are investigated. PBAT/PLA blends have a small difference of solubility parameters, predicting theoretically good miscibility. However, they show two almost unchanged glass transition temperatures in the DSC, phase separation in SEM and two relaxation mechanisms in the Cole–Cole plot. The phase morphology varies depending on both the blend ratios and the preparation techniques. Tensile tests indicate that with increasing PLA content the elongation at break decreases. A good correlation between the elongation at break and the tear propagation resistance is found. Furthermore, the trouser tear method is proven to be more applicable to differentiate highly extensible blown films compared with the Elmendorf tear method.

AI snapshot

Written from the paper’s full text.

TL;DR

Uncompatibilized PBAT/PLA blends were melt-blended across 90/10 to 10/90 ratios and processed into pressed panels, flat films, and blown films to assess manufacturability, miscibility, and properties. Despite close Hildebrand solubility parameters, DSC, SEM, and rheology show limited miscibility and phase separation, while PLA content generally raises modulus but lowers elongation at break and tear propagation resistance.

Key findings

  • Pressed panels were produced at all ratios; flat films failed at PBAT/PLA 50/50 and 40/60; blown films were successfully made only when PBAT was at least 60 wt.% (PLA up to 40 wt.%), with thickness 25 µm and lay-flat width 180 mm using BUR = 2.3, DDR = 40, and FR = 17.5.
  • Miscibility was limited: Hildebrand solubility parameters were close (PBAT 21.9; PLA 20.7 or 19.9 MPa¹/²), but DSC showed two almost unchanged Tg values (~−30 °C and 61 °C) and Tm values (~120 °C/152 °C); for PBAT/PLA 10/90, the Fox equation predicted a single Tg of 42.2 °C, while the detected Tg was 61.4 °C.
  • Rheology and morphology indicated phase separation: the Cole–Cole plot for PBAT/PLA 50/50 showed an S-shape with two relaxation mechanisms and a phase inversion, while SEM showed sea-islands morphology with PLA droplets about 1 µm at 90/10 and phase-separated domains up to 8 µm at 40–60 wt.% PLA.
  • Tensile and tear tests showed increasing PLA reduced elongation at break from approximately 600% for pure PBAT to less than 6% for PBAT/PLA 30/70, 10/90, and neat PLA; the highest blown-film tear propagation resistance was for PBAT/PLA 90/10 at 113.5 ± 2.1 N/mm in CD and 48.9 ± 5.0 N/mm in MD, and trouser tear was more applicable than Elmendorf for highly extensible blown films.

Methods

  • PBAT and PLA were pre-dried and melt-blended in a co-rotating twin-screw extruder at weight ratios from 90/10 to 10/90, then processed into pressed panels, flat films, and blown films.
  • Characterization included DSC for thermal transitions, SEM for cryogenically fractured morphology, rheology for amplitude/frequency sweeps and Cole–Cole plots, tensile testing according to DIN EN ISO 527-3, and tear propagation testing by trouser tear and Elmendorf methods.
  • Tensile data were checked with Origin’s normality test and compared using one-way ANOVA with Tukey analysis.

Limitations

  • Stated: DSC could not determine PLA crystallinity in blends because PBAT melting and PLA cold crystallization overlap; the single Tg for PBAT/PLA 10/90 was attributed to low PBAT content and the low cooling rate; blown-film production became unstable at 40 wt.% PLA and wrinkled with further PLA increases, so target thickness and width were not reachable with the existing equipment; Elmendorf tear results were invalid for PBAT/PLA 90/10 in MD because curved cracks occurred.
  • Evident: the study is restricted to uncompatibilized blends of specific commercial PBAT and PLA grades and to the processing equipment used, so the findings may not directly generalize to compatibilized systems or other processing lines.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.3390/ma13214897

Cites

30 of 30 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

24 of 60 cited sources checked · 10 supported · 2 flagged · accuracy not yet measured

  • Findingown data

    PBAT/PLA blends generally represent two melting temperatures (Tm ~ 120 °C/152 °C) corresponding to those for PBAT and PLA.

    “The PBAT/PLA blends generally represent two separated almost unchanged glass transition temperatures (Tg ~ −30 °C and 61 °C) and two melting temperatures (Tm ~ 120 °C/152 °C) corresponding to those for PBAT and PLA, which is in agreement with the observation of the blends in the literature [12,13].”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites [12] Arruda, 2015, Influence of chain extender on mechanical, thermal and morphological properties of blown films of PLA/PBAT blends, Polym. Test. source

      Section 3.2.2 reports melting temperatures near the cited values for the neat polymers, but explicitly says the PBAT melting region overlapped the PLA cold-crystallization region in the blends. Consequently, the paper determined only the PLA melting temperature in the blends, not two separate melting temperatures. (LLM, conf=0.89)

      Checked by a reasoning model — may be wrong.

      Experimental — accuracy not yet measured
    • cites [13] Sritham, 2018, Tensile properties of PLA/PBAT blends and PLA fibre-reinforced PBAT composite, MATEC Web Conf. source

      Section 3.3 reports two melting temperatures in PLA/PBAT blends, corresponding to PBAT and PLA. However, Table 3 lists blend melting temperatures of 126.3–128.6 °C and 147.5–148.6 °C; the quoted ~120 °C and ~152 °C are closer to the neat polymers’ values of 122.9 °C and 152.9 °C. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
  • Findingreasoning

    PBAT/PLA (70/30) blend panel presents lower tensile strength compared with (100/0), (90/10) and (50/50) panel samples.

    “Compared with these three samples, the (70/30) blend panel presents lower tensile strength, which matches the results of Deng et al. [8].”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [8] Deng, 2018, Optimising Ductility of Poly(Lactic Acid)/Poly(Butylene Adipate-co-Terephthalate) Blends Through Co-continuous Phase Morphology, J Polym Environ. source

      The Tensile Test Results section states that tensile strength decreases as PBAT content increases. For the stated PBAT/PLA ratios, that trend is consistent with 70/30 being weaker than 50/50, but contrary to it being weaker than 90/10 or 100/0. The Sample Preparation section also shows that the paper did not test a 70/30 blend. (LLM, conf=0.83)

      Checked by a reasoning model — may be wrong.

      Experimental — accuracy not yet measured
  • Premisecitation

    When PBAT acts as a polymer matrix (PLA dispersed), the elongation at break increases with decreasing PLA content.

    “When PBAT acts as a polymer matrix, i.e., PLA is the dispersed component, the elongation at break increases, but the modulus of elasticity decreases with decreasing PLA content [13].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [13] Sritham, 2018, Tensile properties of PLA/PBAT blends and PLA fibre-reinforced PBAT composite, MATEC Web Conf. source
  • Premisecitation

    When PBAT is added into the PLA matrix as a dispersed component, the elongation at break increases with increasing PBAT content (10-40 wt.%).

    “When PBAT is added into the PLA matrix as a dispersed component, different studies point that the elongation at break increases, but the tensile strength and modulus of elasticity decrease with increasing PBAT content (10–40 wt.%) [9,10,11].”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites [9] Yeh, 2009, Compatible and crystallization properties of poly(lactic acid)/poly(butylene adipate-co-terephthalate) blends, J. Appl. Polym. Sci. source
    • cites [10] Ferri, 2018, Manufacturing and compatibilization of PLA/PBAT binary blends by cottonseed oil-based derivatives, Express Polym. Lett. source

      The mechanical-properties results report that an uncompatibilized blend with 20 wt% PBAT had greater elongation at break than neat PLA (59.0% versus 29.2%). The Conclusions also say that adding PBAT increases elongation at break. The paper examines a 20 wt% PBAT blend, however, and does not establish that elongation increases progressively as PBAT content rises from 10 to 40 wt%. (LLM, conf=0.87)

      Experimental — accuracy not yet measured
    • cites [11] Farsetti, 2011, Physico-Mechanical Properties of Biodegradable Rubber Toughened Polymers, Macromol. Symp. source
  • Findingown data

    PBAT/PLA blends show two almost unchanged glass transition temperatures in DSC.

    “However, they show two almost unchanged glass transition temperatures in the DSC, phase separation in SEM and two relaxation mechanisms in the Cole–Cole plot.”
    • Also stated in: § 3.3. Thermal Properties and Miscibility · plain
      “The PBAT/PLA blends generally represent two separated almost unchanged glass transition temperatures (Tg ~ −30 °C and 61 °C) and two melting temperatures (Tm ~ 120 °C/152 °C) corresponding to those for PBAT and PLA, which is in agreement with the observation of the blends in the literature [12,13].”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites [12] Arruda, 2015, Influence of chain extender on mechanical, thermal and morphological properties of blown films of PLA/PBAT blends, Polym. Test. source
    • cites [13] Sritham, 2018, Tensile properties of PLA/PBAT blends and PLA fibre-reinforced PBAT composite, MATEC Web Conf. source
  • Classified as probably not a substantial claim. 26
  • May combine two claims. 24
  • The quote only partly states this claim. 1

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    In a PBAT/PLA blend, PBAT can act either as a dispersed component or as a polymer matrix.

    “In a PBAT/PLA blend, PBAT can act either as a dispersed component [9,10] or as a polymer matrix.”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [9] Yeh, 2009, Compatible and crystallization properties of poly(lactic acid)/poly(butylene adipate-co-terephthalate) blends, J. Appl. Polym. Sci. source
    • cites [10] Ferri, 2018, Manufacturing and compatibilization of PLA/PBAT binary blends by cottonseed oil-based derivatives, Express Polym. Lett. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The relevant processing parameters for controlling the bubble-forming process include blow-up ratio (BUR), draw-down ratio (DDR) and forming ratio (FR).

    “The relevant processing parameters (Table 2) include the blow-up ratio (BUR), draw-down ratio (DDR) and the forming ratio (FR) [21].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [21] Cantor, K. (2011). Blown film extrusion, Hanser Publications. [2nd ed.]. source

      The Introduction says process variables influence bubble geometry, and the contents list a section titled “Characteristic Bubble Ratios” (p. 94). However, the passages available from our copy do not identify BUR, DDR, or FR; searches for those terms returned no decisive passage. (LLM, conf=0.72)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The forming ratio (FR) influences molecular orientation and describes the balance of stretching between the cross and machine direction.

    “The FR influences the molecular orientation, meanwhile, describes the balance of stretching between the cross and machine direction [21].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [21] Cantor, K. (2011). Blown film extrusion, Hanser Publications. [2nd ed.]. source

      The Introduction (page unavailable) says bubble dimensions control molecular orientation, but it does not identify the forming ratio or explain stretching in the cross and machine directions. Searches for “forming ratio” and directional stretching returned only introductory text and contents entries, not a passage addressing the specific claim. (LLM, conf=0.72)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    When the PBAT content increases from 40 to 60 wt.%, the modulus of elasticity and tensile strength decrease slightly.

    “When the PBAT content increases from 40 to 60 wt.%, the elongation at break increases dramatically; the modulus of elasticity and tensile strength decrease slightly [12].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [12] Arruda, 2015, Influence of chain extender on mechanical, thermal and morphological properties of blown films of PLA/PBAT blends, Polym. Test. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    PLA can be produced from renewable resources.

    “Moreover, PLA can be produced from renewable resources and biodegrades under industrial composting conditions [7].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [7] Su, S., Kopitzky, R., Tolga, S., and Kabasci, S. (2019). Polylactide (PLA) and Its Blends with Poly(butylene succinate) (PBS): A Brief Review. Polymers, 11. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    PLA biodegrades under industrial composting conditions.

    “Moreover, PLA can be produced from renewable resources and biodegrades under industrial composting conditions [7].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [7] Su, S., Kopitzky, R., Tolga, S., and Kabasci, S. (2019). Polylactide (PLA) and Its Blends with Poly(butylene succinate) (PBS): A Brief Review. Polymers, 11. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    When PBAT acts as a polymer matrix, the modulus of elasticity decreases with decreasing PLA content.

    “When PBAT acts as a polymer matrix, i.e., PLA is the dispersed component, the elongation at break increases, but the modulus of elasticity decreases with decreasing PLA content [13].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [13] Sritham, 2018, Tensile properties of PLA/PBAT blends and PLA fibre-reinforced PBAT composite, MATEC Web Conf. source

      Section 3.1.1 reports a higher elastic modulus at 40% PLA than at lower PLA concentrations, which supports a decrease when moving below 40%. But it says neat PBAT and blends with 10%, 20%, and 30% PLA did not differ significantly in modulus, so it does not support a decrease with every reduction in PLA content. The supplied passages do not give page numbers. (LLM, conf=0.86)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Melt blending is a method to mix polymers without chemical reactions taking place.

    “Melt blending is a method to mix some polymers without chemical reactions taking place [8].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [8] Deng, 2018, Optimising Ductility of Poly(Lactic Acid)/Poly(Butylene Adipate-co-Terephthalate) Blends Through Co-continuous Phase Morphology, J Polym Environ. source

      The Sample Preparation section describes melt blending PLA and PBAT in a mixer that promotes mixing. Neither that section nor the Introduction establishes that chemical reactions do not take place during melt blending, so the no-reaction part of the claim is unsupported. (LLM, conf=0.84)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    PBAT is an aliphatic-aromatic copolyester.

    “PBAT is an aliphatic-aromatic copolyester [2,3], which is biodegradable, highly flexible and designed for film extrusion [4,5].”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [2] BASF, SE (2020, October 30). Better Soil, Higher Yield and More Taste for Tomatoes, Certified Soil-Biodegradable Ecovio® M2351 for Mulch Films Benefits Food Production and Environment. Available online: https://www.basf.com/global/en/media/news-releases/2019/08/p-19-308.html.

      Not checked in the free run.

    • cites [3] Jiao, 2020, An overview on synthesis, properties and applications of poly(butylene-adipate-co-terephthalate)–PBAT, Adv. Ind. Eng. Polym. Res. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    When the PBAT content increases from 40 to 60 wt.%, the elongation at break increases dramatically.

    “When the PBAT content increases from 40 to 60 wt.%, the elongation at break increases dramatically; the modulus of elasticity and tensile strength decrease slightly [12].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [12] Arruda, 2015, Influence of chain extender on mechanical, thermal and morphological properties of blown films of PLA/PBAT blends, Polym. Test. source

      Section 3.2.4 (page unavailable) reports 325% elongation at break for 40PLA (60 wt.% PBAT) and describes low ductility for 60PLA (40 wt.% PBAT) without chain extender, supporting a substantial increase for those unextended blends. The claim omits the chain-extender condition: the paper reports that adding extender sharply reduces elongation in 40PLA but raises it in 60PLA, so it does not establish the same comparison for all formulations. (LLM, conf=0.78)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Findingown data

    PBAT/PLA (60/40) exhibits in MD stratified phases and PBAT is the continuous phase.

    “PBAT/PLA (60/40) exhibits in MD stratified phases and PBAT is the continuous phase”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [12] Arruda, 2015, Influence of chain extender on mechanical, thermal and morphological properties of blown films of PLA/PBAT blends, Polym. Test. source

      Section 2.1.2 identifies 40PLA as 40% PLA, and section 3.2.3 says PLA is its dispersed phase, supporting PBAT as the continuous phase. The same section describes elongated, fibrillar PLA structures oriented in the drawing direction (MD), not stratified phases; that description does not establish the claimed stratification. Page numbers were unavailable in our copy. (LLM, conf=0.83)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Findingnone given

    Flat films with a thickness of approximately 110 μm and a width of around 130 mm are producible with most PBAT/PLA blends, but production fails when the PBAT/PLA blend ratio is 50/50 or 40/60.

    “Flat films with a thickness of approximately 110 µm and a width of around 130 mm are producible with most blends. However, it fails when the PBAT/PLA blend ratio is 50/50 or 40/60.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The second heating scan of pure PBAT indicates a Tg at −28.3 °C and a Tm of 120.4 °C.

    “The second heating scan of the pure PBAT indicates a Tg at −28.3 °C and a Tm of 120.4 °C (Table 4)”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingreasoning

    The melting peak of PLA (0/100) is very weak but detectable by the analytical software.

    “The melting peak of PLA (0/100) is very weak, but it is detectable by the analytical software (Figure S1).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    A further increase of PLA content leads to increasingly wrinkled blown films, and the mentioned thickness and width are not reachable using the existing equipment.

    “A further increase of the PLA content leads to wrinkles of blown films increasingly (Figure 1); furthermore, the mentioned thickness and width are not reachable any more using the existing equipment.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    The Hildebrand solubility parameter of PLA is 20.7 or 19.9 MPa^1/2.

    “Hildebrand SP of PBAT is 21.9 and the one of PLA is 20.7 or 19.9 [MPa1/2] respectively (Table 3).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The Tg and Tm of neat PLA are 61.6 and 149.6 °C, respectively.

    “The Tg and Tm of neat PLA are 61.6 and 149.6 °C, respectively.”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    The morphology of the flat films differs greatly in the CD and MD directions.

    “The morphology of the flat films differs greatly in the directions.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    With the same parameter settings in blown film production and increasing PLA content (10-40 wt.%), the tensile strength of blown films tends to decrease in CD but increase in MD while the elongation at break increases.

    “With the same parameter settings in blown film production and increasing PLA content (10–40 wt.%), the tensile strength of blown films tends to decrease in CD but increase in MD while the elongation at break increases.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    PBAT/PLA (90/10) blend presents a smooth surface with small spherical PLA droplets of about 1 μm.

    “The PBAT/PLA (90/10) blend presents a smooth surface with small spherical PLA droplets of about 1 µm.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    Optical homogenous panels (thickness: 0.8 μm) were pressed with all blend ratios.

    “Optical homogenous panels (thickness: 0.8 µm) were pressed with all blend ratios.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The Cole-Cole-Plot shows two different relaxation mechanisms correspond to two phases in PBAT/PLA (50/50) and a phase inversion from a droplet-matrix morphology to a co-continuous morphology in the internal structure.

    “The Cole–Cole-Plot shows two different relaxation mechanisms correspond to two phases in PBAT/PLA (50/50) and a phase inversion from a droplet-matrix morphology to a co-continuous morphology in the internal structure.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    SEM presents two-phase characteristics of PBAT/PLA blends and anisotropic morphologies of flat films caused by melting stretching in the processing process.

    “SEM presents two-phase characteristics of PBAT/PLA blends and anisotropic morphologies of flat films caused by melting stretching in the processing process.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    PLA exhibits high tensile strength and modulus.

    “Compared with PBAT, PLA exhibits attractive mechanical and physical properties such as high tensile strength and modulus [4].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [4] Nofar, 2019, Poly (lactic acid) blends: Processing, properties and applications, Int. J. Biol. Macromol. source

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationreasoning

    A competitive material cost is achievable by blending PBAT and PLA with a high PLA content because PLA is relatively inexpensive compared with PBAT.

    “A competitive material cost is achievable by blending PBAT and PLA with a high PLA content, because compared with PBAT, PLA is now relatively inexpensive.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    PBAT is highly flexible.

    “PBAT is an aliphatic-aromatic copolyester [2,3], which is biodegradable, highly flexible and designed for film extrusion [4,5].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [4] Nofar, 2019, Poly (lactic acid) blends: Processing, properties and applications, Int. J. Biol. Macromol. source
    • cites [5] Lamnawar, 2012, Improvement of thermal stability, rheological and mechanical properties of PLA, PBAT and their blends by reactive extrusion with functionalized epoxy, Polym. Degrad. Stab. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Tear propagation resistance is commonly determined using the Elmendorf tear test or trouser tear test.

    “Tear propagation resistance is commonly determined using the Elmendorf tear test [17,18] or trouser tear test [19,20].”
    Quote in the paperNot a substantial claim0 of 4 sources checked
    • cites [17] ASTM Committee D20 (2009). ASTM D1922-09: Standard Test Method for Propagation Tear Resistance of Plastic Film and Thin Sheeting by Pendulum Method, ASTM International. source
    • cites [18] DIN German Institute for Standardization (2019, July 03). DIN EN ISO 6383-1: Plastics—Film and sheeting—Determination of tear resistance—Part 1: Trouser tear method; Beuth Verlag GmbH. Available online: https://www.beuth.de/de/norm/din-en-iso-6383-1/248007005.

      Not checked in the free run.

    • cites [19] ASTM Committee D20 (2002). ASTM D1938: Test Method for Tear-Propagation Resistance (Trouser Tear) of Plastic Film and Thin Sheeting by a Single-Tear Method, ASTM International. source
    • cites [20] DIN German Institute for Standardization (2019, July 03). DIN EN ISO 6383-2: Plastics—Film and sheeting—Determination of tear resistance—Part 2: Elmendorf method. Available online: https://www.beuth.de/de/norm/din-en-iso-6383-2/74093806.

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    PBAT is designed for film extrusion.

    “PBAT is an aliphatic-aromatic copolyester [2,3], which is biodegradable, highly flexible and designed for film extrusion [4,5].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [4] Nofar, 2019, Poly (lactic acid) blends: Processing, properties and applications, Int. J. Biol. Macromol. source
    • cites [5] Lamnawar, 2012, Improvement of thermal stability, rheological and mechanical properties of PLA, PBAT and their blends by reactive extrusion with functionalized epoxy, Polym. Degrad. Stab. source

  • May combine two claims.

    Premisecitation

    PLA suffers from brittleness and low toughness at ambient conditions.

    “However, PLA suffers from its brittleness and low toughness at ambient conditions [4], due to its molecular structure with a relatively rigid backbone and small methyl side groups.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [4] Nofar, 2019, Poly (lactic acid) blends: Processing, properties and applications, Int. J. Biol. Macromol. source

  • May combine two claims.

    Premisecitation

    High cost (≈5 $/kg) and insufficient material properties limit applications of PBAT/PLA blends.

    “However, the high cost (≈5 $/kg) and the insufficient material properties still limit the applications [14].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [14] Hamad, 2018, Polylactic acid blends: The future of green, light and tough, Prog. Polym. Sci. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    PBAT is biodegradable.

    “PBAT is an aliphatic-aromatic copolyester [2,3], which is biodegradable, highly flexible and designed for film extrusion [4,5].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [4] Nofar, 2019, Poly (lactic acid) blends: Processing, properties and applications, Int. J. Biol. Macromol. source
    • cites [5] Lamnawar, 2012, Improvement of thermal stability, rheological and mechanical properties of PLA, PBAT and their blends by reactive extrusion with functionalized epoxy, Polym. Degrad. Stab. source

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationnone given

    PBAT/PLA blends have a small difference of solubility parameters, predicting theoretically good miscibility.

    “PBAT/PLA blends have a small difference of solubility parameters, predicting theoretically good miscibility.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    PBAT and PLA show some compatibility in the MD of their flat films, although they have shown poor miscibility in DSC and SEM.

    “Therefore, PBAT and PLA show some compatibility in the MD of their flat films, although they have shown poor miscibility in DSC and SEM.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The modulus of elasticity is predictable using the rules of mixing, with Parallel Model and Series Model predicting the upper and lower boundaries of blend behavior, respectively.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The morphology including the size and size distribution of the minor phase influences the mechanical properties of a blend.

    “The morphology including the size and size distribution of the minor phase influences the mechanical properties of a blend [30].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [30] Lu, 2017, Morphology and properties of biodegradable poly (lactic acid)/poly (butylene adipate-co-terephthalate) blends with different viscosity ratio, Polym. Test. source

  • May combine two claims.

    Interpretationnone given

    The results of the Elmendorf tear method depend strongly on the course of crack during the test: straight cracks result in low values; curved cracks cause higher values.

    “The results depend strongly on the course of crack during the test: straight cracks result in low values; curved cracks cause higher values.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Tear resistance plays an important role in the mechanical properties of a blown film.

    “In addition to the tensile properties, tear resistance also plays an important role in the mechanical properties of a blown film [32].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [32] Spoljaric, 2015, Ductile nanocellulose-based films with high stretchability and tear resistance, Eur. Polym. J. source

  • May combine two claims.

    Interpretationown data

    The failure of flat film production at PBAT/PLA blend ratios of 50/50 or 40/60 is probably due to the morphological change from droplet-matrix to co-continuous phases in internal structure, which is confirmed in the rheological test.

    “The reason is probably the morphological change from droplet-matrix to co-continuous phases in internal structure, which is confirmed in the rheological test.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    The left side of the S-shape shows relaxation of one blend component (polymer matrix) and the right side is attributed to another blend component (droplet relaxation).

    “The left side shows the relaxation of one blend component (polymer matrix) and the right side is attributed to another blend component (droplet relaxation) [26,27,28].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [26] Li, 2011, Dynamic rheological behavior and morphology of polylactide/poly(butylenes adipate-co-terephthalate) blends with various composition ratios, Adv. Polym. Technol. source
    • cites [27] Lamnawar, 2014, Rheological, morphological, and interfacial properties of compatibilized PLA/PBAT blends, Rheol. Acta. source
    • cites [28] Dil, 2015, Morphology, miscibility and continuity development in poly(lactic acid)/poly(butylene adipate-co-terephthalate) blends, Polymer source

  • Classified as probably not a substantial claim.

    Premisecitation

    If PBAT and PLA were miscible at the molecular level, then there should be a shift in the glass transition temperatures according to the Fox Equation.

    “If PBAT and PLA were miscible at the molecular level, then there should be a shift in the glass transition temperatures according to the Fox Equation (1) [24]:”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [24] Brostow, 2008, Prediction of glass transition temperatures: Binary blends and copolymers, Mater. Lett. source

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationreasoning

    The elongated ribbon-like PLA phase in MD is probably due to the orientation of the polymer chains.

    “probably due to the orientation of the polymer chains.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Full miscibility of a polymer blend is characterized by a single Tg; in a partially miscible system, there are two Tg values that depend on composition; immiscible polymers show two Tg values for pure components without changes at different compositions.

    “The full miscibility of a polymer blend is characterized by a single Tg; In a partially miscible system, there are two Tg values that depend on the composition; Immiscible polymers show two Tg values for pure components without changes at different compositions.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [24] Brostow, 2008, Prediction of glass transition temperatures: Binary blends and copolymers, Mater. Lett. source

  • May combine two claims.

    Interpretationown data

    The modulus of elasticity of flat films in MD fits the upper limit of the blend behavior, indicating some compatibility despite limited miscibility.

    “Taking the standard deviation into account, the modulus of elasticity of flat films in MD fits the upper limit of the blend behavior, indicating some compatibility despite limited miscibility.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The resistance to tear propagation is expected to be much lower than the resistance of tear initiation.

    “The resistance to tear propagation is expected to be much lower than the resistance of tear initiation [33].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [33] Briassoulis, 2006, Mechanical behaviour of biodegradable agricultural films under real field conditions, Polym. Degrad. Stab. source

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    The thicker the samples, the greater the probability of defects in the sample.

    “The thicker the samples, the greater the probability of defects in the sample.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    The reason for the dramatic decrease of pure PBAT complex viscosity is maybe the increasing loss of physical entanglements at higher frequencies at 160 °C.

    “The reason for this is maybe the increasing loss of physical entanglements at higher frequencies at 160 °C.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    The measured Tg values are inconsistent with the values calculated using the Fox equation, indicating limited miscibility between PBAT and PLA.

    “The measured values are inconsistent with the values calculated using the Fox equation, indicating limited miscibility between PBAT and PLA.”
    Quote in the paperSubstantial claim
46 of 46

  • The paper relies on this without support.

    Tear propagation resistance is required for blown film applications.

    “In addition to the tensile properties, tear propagation resistance is also required for blown film applications.”

  • The paper relies on this without support.

    Prior PBAT/PLA blend tensile test results are difficult to compare because the dimensions of test specimens, production methods and measurement conditions used are different.

    “In recent years, numerous studies have been performed on PBAT/PLA blends, but the dimensions of the test specimens, the production methods and measurement conditions used are different so that the tensile test results are difficult to compare.”

  • The paper relies on this without support.

    The material properties of a polymer blend depend strongly on the processing and the miscibility of the components.

    “However, the material properties of a polymer blend depend strongly on the processing and the miscibility of the components.”

  • The paper relies on this without support.

    Pressed panels are isotropic, so test specimens obtained from them do not differ in different directions.

    “Due to the isotropy, test specimens obtained from pressed panels do not differ in different directions.”

  • The paper relies on this without support.

    Flat films and blown films have anisotropy due to the orientation of the polymer chains during processing.

    “Flat films and blown films have anisotropy due to the orientation of the polymer chains during processing.”

  • The paper relies on this without support.

    Both PBAT and PLA have almost the same density (1.25 kg/m3).

    “Both polymers have almost the same density (1.25 kg/m3).”

  • The authors state this as an assumption.

    The modulus of elasticity is predictable using the rules of mixing, with Parallel Model and Series Model predicting the upper and lower boundaries of blend behavior, respectively.

    “The modulus of elasticity (MOE) is predictable using the rules of mixing. Parallel Model (2) and Series Model (3) predict the upper and lower boundaries of blend behavior, respectively.”

  • The paper relies on this without support.

    Sufficient tear propagation resistance of blown films is required, and a minimum possible film thickness is necessary to achieve competitive material costs and enhanced biodegradability.

    “Moreover, not only the sufficient tear propagation resistance of blown films is required, but also a minimum possible film thickness is necessary to achieve competitive material costs and enhanced biodegradability.”

  • The paper relies on this without support.

    The tear propagation resistance of PBAT/PLA blend films is compared for the first time using two tear propagation test methods.

    “To our best knowledge, the tear propagation resistance of PBAT/PLA blend films is compared for the first time using two tear propagation test methods.”

  • The paper relies on this without support.

    Hildebrand solubility parameters of PBAT and PLA are close, predicting theoretically good miscibility between them.

    “Hildebrand solubility parameters of PBAT and PLA are close, predicting theoretically good miscibility between them.”

  • The paper relies on this without support.

    Improved mechanical properties, especially tear propagation resistance, are required for film applications of PBAT/PLA blends.

    “Improved mechanical properties especially the tear propagation resistance are required for film applications of PBAT/PLA blends.”
11 of 11

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Conclusion reverses the elongation-at-break trend

    Major

    The conclusion says elongation at break increases as PLA content rises from 10 to 40 wt.%, whereas the results say it decreases over that range in both film types and directions.

  • Pressed-panel thickness differs by a factor of 1,000

    Minor

    The conclusions give the panel thickness as 0.8 μm, while the results give it as 800 μm.

2 of 2

Cites

Flagged first, then by citations

Cited by

Still being checked.

Related

Authors
Su, S., Duhme, M., & Kopitzky, R.
Affiliations
Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT (DE)
Corresponding author
Su, Shen
ORCID
Venue
Materials
Publisher
MDPI AG
Published
2020-10-31
Volume
13
Issue
21
Pages
4897
ISSN
1996-1944 (ISSN-L)
DOI
10.3390/ma13214897
PMC
PMC7662590
OpenAlex
W3096254705
Semantic Scholar
cdf5a1d83b55ef74f373002f6484efc810817f8d
Cited by
159
References
30
Citations by year
2026: 32 · 2025: 41 · 2024: 35 · 2023: 21 · 2022: 21 · 2021: 7 · 2020: 2
FWCI
4.86
Type
journal article
Language
en
Open access
Licence
Locations
  • Materials (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • Publikationsdatenbank der Fraunhofer-Gesellschaft (Fraunhofer-Gesellschaft) (submittedVersion, other-oa)
  • Fraunhofer-Publica (Fraunhofer-Gesellschaft) (submittedVersion)
Funders
Saudi Basic Industries Corporation
Topics
  • Physical Sciences › Materials Science › Polymers and Plastics › Polymer crystallization and properties
  • Physical Sciences › Materials Science › Biomaterials › biodegradable polymer synthesis and properties
  • Physical Sciences › Materials Science › Materials Chemistry › Block Copolymer Self-Assembly
Keywords
poly(butylene adipate-co-terephthalate), polylactic acid, polymer blends, blend miscibility, phase separation, melt blending, blown film, solubility parameter, glass transition temperature, mechanical properties, elongation at break, rheology, morphology (materials science), packaging films, agricultural films

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-28.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-28.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

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