Master of Chaos and Order: Opposite Microstructures of PCL‐co‐PGA‐co‐PLA Accessible by a Single Catalyst**

May combine two claims.

Polymerizations of monomer mixtures feature enhanced transesterifications and yield di- and terpolymers with highly dispersed repeating unit distributions.

“Sequential addition of monomers yields highly ordered block copolymers including the symmetrical PLA‐b‐PGA‐b‐PCL‐b‐PGA‐b‐PLA pentablock copolymers, while polymerizations of monomer mixtures feature enhanced transesterifications and pave the way to di‐ and terpolymers with highly dispersed repeating unit distributions.”

May combine two claims.

For homopolymerization of Cap with 1 under solvent-free conditions at 150 °C, kp is (5.97±1.55)×10−3 L mol−1 s−1, two orders of magnitude lower than the kp for LL.

“For this study, the k p of the homopolymerization of Cap with 1 as catalyst under solvent‐free conditions at 150 °C was determined to be (5.97±1.55)×10−3 L mol−1 s−1 and thus two orders of magnitude lower in comparison with the k p for LL (see Figure S2). [27]”

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

The share of GG was limited to 10% since higher ratios would lead to the insolubility of the copolymer in common organic solvents.

“The share of GG was limited to 10 % since higher ratios would lead to the insolubility of the copolymer in common organic solvents.”

• AssumptionRests on an assumption: Higher ratios of GG would lead to the insolubility of the copolymer in common organic solvents.

May combine two claims.

In random copolymerization experiments with total M/CoI/Cat ratio 1000:1:1 and BnOH, high conversions were found for all monomers, with lowest values around 70% when Cap or LL was the minor monomer, while GG reached full conversion throughout.

“High conversions are found for all monomers in the copolymerization experiment, nevertheless, lowest values are around 70 % when Cap or LL is the minor monomer, while GG reaches full conversion throughout the experiments.”

May combine two claims.

The sequence lengths of LL and GG can be below 1, with a minimum of 0.5, if all repeating units are divided by second mode transesterification; this is the case for PCL-co-PGA (Table 2, run 8).

“The sequence lengths of LL and GG can be below 1 with a minimum of 0.5, if all repeating units are divided by second mode transesterification. This is the case for PCL‐co‐PGA (Table 2, run 8).”

May combine two claims.

In GPC analysis of the random copolymers, the average chain lengths are much lower than the theoretical ones and dispersities are high up to Đ=1.72.

“When analyzing the produced copolymers with GPC, it was found for all copolymers that the average chain lengths are much lower than the theoretical ones and show quite high dispersities of up to Đ=1.72 indicating a deviation from controlled molar mass growth and the occurrence of transesterifications.”

May combine two claims.

The molar masses of the polymers produced under immortal conditions fit the theoretical ones very well and show dispersities below 1.10.

“The molar masses of the polymers produced under immortal conditions fit the theoretical ones very well and show dispersities below 1.10 (see Table S2).”

May combine two claims.

The average sequence length increases for LL and Cap if they are present in excess and decreases if they are the minor component.

“The average sequence length increases for LL and Cap if they are present in excess and decrease if they are the minor component.”

May combine two claims.

The 13C{1H} NMR carbonyl region of the PLA-PCL product from sequential addition only displays peaks typical of a blocky microstructure, with long sequences of each repeat unit and no peaks of isolated repeat units that would signify transesterification.

“The carbonyl region of the 13C{1H} NMR spectrum only displays peaks that are typical of a PLA‐PCL blocky microstructure, namely, long sequences of each of the repeat units (i.e., CapCapCap and LLLLLL), but no peaks of isolated repeat units in between the repeat units of the opposite monomer that would signify transesterification (see Figure 1A).”

May combine two claims.

In sequential addition, even after two batches of monomers had been polymerized before, the polymerization of LL still follows first order kinetics and reaches high conversions.

“It is remarkable that even after having polymerized two batches of monomers before, the polymerization of LL still follows first order kinetics and reaches high conversions supporting a truly living polymerization.”

The quote only partly states this claim.

Small signals of the transition between the blocks are visible in the carbonyl regions.

“Additionally to the homotriads, small signals of the transition between the blocks are visible.”

May combine two claims.

Block copolymers were prepared with BnOH as monofunctional or 1,4-benzenedimethanol (BDM) as bifunctional co-initiator, resulting in AB(C) or (C)BAB(C) block copolymers.

“Block copolymers were prepared with BnOH as monofunctional or 1,4‐benzenedimethanol (BDM) as bifunctional co‐initiator resulting in AB(C) or (C)BAB(C) block copolymers.”

May combine two claims.

The catalyst 1 is active even in the presence of 500 equiv. of BnOH as co-initiator with 10 000 equiv. of LL, supporting high stability towards protic compounds.

“We found that the catalyst is active even in the presence of 500 equiv. of BnOH as co‐initiator with 10 000 equiv. of LL supporting once again the high stability of this complex towards protic compounds.”

May combine two claims.

The average molar masses match the theoretical values very well and the dispersities are low with a maximum of 1.33.

“The average molar masses match the theoretical values very well and the dispersities are with a maximum of 1.33 low.”

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

The immortal conditions employed reduce the amount of catalyst necessary for the polymerization.

“The immortal conditions employed, which reduce the amount of catalyst necessary for the polymerization, round up the picture”

May combine two claims.

Even though the total M/CoI/Cat ratio is maintained and GG constitutes only 10% of the monomer mixture, the conversion is nearly twice as high in the presence of GG.

“Even though the total M/CoI/Cat ratio is maintained and GG constitutes only 10 % of the monomer mixture, the conversion is nearly twice as high in its presence.”

May combine two claims.

When only LL and Cap are copolymerized, the same ratio of CapX and CapCap is observed, but the total conversion of Cap is lower.

“When only LL and Cap are copolymerized the same ratio of CapX and CapCap is observed, however, the total conversion of Cap is lower (see Figure 5 bottom).”

May combine two claims.

In the scaled-up terpolymerization, GG is the first monomer to be polymerized; after only 10 min full conversion is reached.

“The graph of the terpolymer shows that GG is the first monomer to be polymerized. After only 10 min full conversion is reached.”

May combine two claims.

When a block copolymer (PCL-b-PLA, Table 1, run 1) is heated with freshly added catalyst in a ratio of 1000:1 for 24 h at 180 °C, the blocky structure is maintained and only very small peaks resulting from a low degree of transesterification are detected.

“When a block copolymer (PCL‐b‐PLA, Table 1, run 1) is heated with freshly added catalyst in a ratio of 1000 : 1 (referring to the monomers incorporated) for 24 h at 180 °C, the blocky structure is maintained and only very small peaks resulting from a low degree of transesterification could be detected (see Figure S4).”

May combine two claims.

During the first hour, very small amounts of Cap are converted; significant conversion of Cap is only found after reaction times of more than one hour.

“During this time very small amounts of Cap are converted, significant conversion is only found after reaction times of more than one hour.”

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

For lactide, ε-caprolactone (Cap) has proven to be a suitable counterpart.

“For lactide (LL), ϵ‐caprolactone (in this publication: Cap) has proven to be a suitable counterpart. [9]”

• cites [9] sourceNot checked yet

  Not checked in the free run.

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

To synthesize random copolymers, the reactivity ratios should best be equal, which remains a challenge for most catalysts.

“To synthesize random copolymers, the reactivity ratios should best be equal which remains a challenge for most catalysts.”

Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

Desirable microstructures are either blocky or random, since the building block distribution of other microstructures is not distinctly defined and thus the properties of a likewise called polymer can vary significantly.

“Desirable microstructures are either blocky or random, since the building block distribution of the other microstructures are not distinctly defined and thus the properties of a likewise called polymer can vary significantly.”

• cites [15] R. G. Jones, T. Kitayama, K.-H. Hellwich, M. Hess, A. D. Jenkins, J. Kahovec, P. Kratochvíl, I. Mita, W. Mormann, C. K. Ober, Pure Appl. Chem. 2016, 88, 1073– 1100.Not checked yet

  Not checked in the free run.

Classified as probably not a substantial claim.

Combining the three monomers LL, Cap and GG in one copolymer allows the tuning of the polymer properties to a large extent.

“Combining the three monomers LL, Cap and GG in one copolymer allows the tuning of the polymer properties to a large extent. [14]”

• cites [14] Q. Cai, J. Bei, S. Wang, J. Biomater. Sci. Polym. Ed. 2000, 11, 273– 288. 10841279 sourceNot checked yet

  Not checked in the free run.

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

It was reported that Cap cannot be polymerized after LL.

“The reactivity ratios in the copolymerization are for most catalysts in the order r GG>r LL≫r Cap and it was reported that Cap cannot be polymerized after LL. [17]”

• cites [17]Not checked yet

  Not checked in the free run.

May combine two claims.

The mechanical properties of PLA face limitations such as high rigidity or unsuited degradation time, which are necessary to overcome to make the bioplastic widely applicable.

“However, the mechanical properties of PLA face some limitations like a high rigidity or unsuited degradation time, which are necessary to overcome in order to make the bioplastic widely applicable. [7]”

• cites [7] sourceNot checked yet

  Not checked in the free run.

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

Aluminum complexes with elaborated, bulky ligands are performing best in the synthesis of random copolymers.

“Aluminum complexes with elaborated, bulky ligands are performing best in this discipline.[ 17c , 20 ]”

• cites [17c, 20]Not checked yet

  Not checked in the free run.

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

PLA-b-PCL-b-PLA copolymers, resulting in a soft block surrounded by hard ones, are interesting due to their properties as thermoplastic elastomers.

“Especially PLA‐b‐PCL‐b‐PLA copolymers, resulting in a soft block surrounded by hard ones, are interesting due to their properties as thermoplastic elastomers. [12]”

• cites [12] sourceNot checked yet

  Not checked in the free run.

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

The catalyst 1 follows the coordination-insertion mechanism.

“Its polymerization properties for lactide in bulk at 150 °C was already investigated, a k p of (0.554±0.024) L mol−1 s−1 was determined and it was shown that the catalyst follows the coordination–insertion mechanism. [27]”

• cites [27] R. D. Rittinghaus, P. M. Schäfer, P. Albrecht, C. Conrads, A. Hoffmann, A. N. Ksiazkiewicz, O. Bienemann, A. Pich, S. Herres-Pawlis, ChemSusChem 2019, 12, 2161– 2165. 30811863 sourceNot checked yet

  Not checked in the free run.

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

The relative reactivity towards the monomers is important for the formation of block copolymers, which are typically produced by sequential addition.

“The relative reactivity towards the monomers is important for the formation of block copolymers which are typically produced by sequential addition. [19]”

• cites [19] sourceNot checked yet

  Not checked in the free run.

Classified as probably not a substantial claim.

By increasing the reaction temperature, some highly active catalysts are capable of reaching a uniform distribution of the building units by transesterification.

“However, by increasing the reaction temperature, some highly active catalysts are capable of reaching a uniform distribution of the building units by transesterification. [22]”

• cites [22] sourceNot checked yet

  Not checked in the free run.

Classified as probably not a substantial claim.

The reactivity ratios in the copolymerization for most catalysts are in the order rGG > rLL ≫ rCap.

“The reactivity ratios in the copolymerization are for most catalysts in the order r GG>r LL≫r Cap and it was reported that Cap cannot be polymerized after LL. [17]”

• cites [17]Not checked yet

  Not checked in the free run.

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

Glycolide forms the hydrophilic polymer polyglycolide (PGA), leading to faster degradation.

“The set of comonomers is completed by glycolide (GG), which forms the hydrophilic polymer polyglycolide (PGA) leading e.g., to a faster degradation. [13]”

• cites [13] sourceNot checked yet

  Not checked in the free run.

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

When using Sn(Oct)2 as catalyst, the temperature influences the occurrence of transesterifications and the average sequence length, but to a lesser extent than for other catalysts.

“It was reported that, when using Sn(Oct)2 as catalyst, the temperature influences the occurrence of transesterifications and the average sequence length, but to a lesser extent than for other catalysts. [25]”

• cites [25]Not checked yet

  Not checked in the free run.

May combine two claims.

Otherwise, only low degrees of randomness and the formation of micro blocks were observed with Sn(Oct)2.

“Otherwise, only low degrees of randomness and the formation of micro blocks was observed.[ 23b , 26 ]”

• cites [23b, 26]Not checked yet

  Not checked in the free run.

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

The opposite was reported as well, with catalysts preferably consuming Cap.

“But the opposite was reported as well with catalysts preferably consuming Cap. [18]”

• cites [18] sourceNot checked yet

  Not checked in the free run.

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

The characteristics of a copolymer depend on the ratios of the monomers as well as the microstructure, which can vary from blocky via gradient and statistical to random.

“The characteristics of a copolymer depend on the ratios of the monomers as well as the microstructure which can vary from blocky via gradient and statistical to random. [15]”

• cites [15] R. G. Jones, T. Kitayama, K.-H. Hellwich, M. Hess, A. D. Jenkins, J. Kahovec, P. Kratochvíl, I. Mita, W. Mormann, C. K. Ober, Pure Appl. Chem. 2016, 88, 1073– 1100.Not checked yet

  Not checked in the free run.

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

The occurrence of transesterifications typically depends on the reaction temperature and normally they are avoided to preserve a controlled polymerization.

“The occurrence of transesterifications typically depends on the reaction temperature and normally they are avoided to preserve a controlled polymerization.[ 18a , 21 ]”

• cites [18a, 21]Not checked yet

  Not checked in the free run.

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

In comparison to PLA, polycaprolactone (PCL) is more flexible due to a lower glass transition temperature and shows prolonged degradation times.

“In comparison to PLA, polycaprolactone (PCL) is more flexible due to a lower glass transition temperature and shows prolonged degradation times. [11]”

• cites [11]Not checked yet

  Not checked in the free run.

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

Block copolymers of PCL and PLA were approached by sequential addition, but a sharp transition between the blocks in the resulting copolymers could only be attained if the PCL prepolymer was purified before the addition of the second monomer.

“Block copolymers of PCL and PLA were approached by sequential addition, however, a sharp transition between the blocks in the resulting copolymers could only be attained if the PCL prepolymer was purified before the addition of the second monomer.[ 23b , 24b ]”

• cites [23b, 24b]Not checked yet

  Not checked in the free run.

May combine two claims.

Defined block copolymers produced under melt conditions as well as highly randomized copolymers synthesized by a single catalyst remain a challenge.

“Especially, defined block copolymers produced under melt conditions as well as highly randomized copolymers synthesized by a single catalyst remain a challenge.[ 17k , 23a , 24 ]”

• cites [17k, 23a, 24]Not checked yet

  Not checked in the free run.

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

Other catalysts promote transesterifications only to a lesser extent and rather produce statistical copolymers with a blocky character.

“Other catalysts promote transesterifications only to a lesser extent and rather produce statistical copolymers with a blocky character. [23]”

• cites [23] sourceNot checked yet

  Not checked in the free run.

May combine two claims.

1 is capable of homopolymerizing lactide under immortal conditions to highly defined PLA and shows the same accuracy when several monomers are added throughout the polymerization.

“1 is therefore not only capable of homopolymerizing lactide under immortal conditions to highly defined PLA (see Table S2), but shows the same accuracy when several monomers are added throughout the polymerization.”

May combine two claims.

In literature, rarely any examples of terpolymers of LL, GG and Cap with separated blocks can be found, while block copolymers of two of these monomers are vastly present.

“In literature, rarely any examples of terpolymers of LL, GG and Cap with separated blocks can be found, while block copolymers of two of these monomers are vastly present.”

• cites [30] sourceNot checked yet

  Not checked in the free run.

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

Since the polymerizations were performed under solvent-free conditions, full conversion is hardly achievable due to diffusion limitation.

“Since the polymerizations were performed under solvent‐free conditions, full conversion is hardly achievable due to diffusion limitation.”

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

From a catalytic point of view there is no indication that higher ratios of GG would be problematic.

“However, from a catalytic point of view there is no indication that higher ratios of GG would be problematic.”

May combine two claims.

The lower average chain lengths and high dispersities indicate a deviation from controlled molar mass growth and the occurrence of transesterifications.

“When analyzing the produced copolymers with GPC, it was found for all copolymers that the average chain lengths are much lower than the theoretical ones and show quite high dispersities of up to Đ=1.72 indicating a deviation from controlled molar mass growth and the occurrence of transesterifications.”

May combine two claims.

CapGCap and CapLCap building blocks cannot form by traditional addition of a monomer but are the result of second mode transesterification, which splits a monomer consisting of two repeating units like LL or GG and leaves a single repeating unit surrounded by two others.

“Both building blocks cannot form by traditional addition of a monomer but are the result of a so‐called second mode transesterification which splits a monomer consisting of two repeating units like LL or GG and leaves a single repeating unit surrounded by two others.”

• cites [21c]Not checked yet

  Not checked in the free run.

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

The formation of two unconnected homopolymers or species with different compositions produced by ambiguous initiation cannot be excluded.

“1 is known to act as a single site catalyst [27] therefore, the formation of two unconnected homopolymers or species with different compositions produced by ambiguous initiation cannot be excluded.”

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

A catalyst for uniformly random copolymer must be stable at high temperatures since transesterifications are enhanced by increased polymerization temperature, and the interplay between polymerization preference and tendency for transesterification must be balanced.

“Here, a catalyst fulfilling special criteria is necessary: It has to be stable at high temperatures since transesterifications are enhanced by an increased polymerization temperature. Furthermore, the interplay between the polymerization preference and the tendency for transesterification has to be balanced.”

Classified as probably not a substantial claim.

Monomers with different copolymerization reactivity ratios like LL, GG and Cap are a challenge when random copolymers are desired.

“Monomers with different copolymerization reactivity ratios like LL, GG and Cap are a challenge when random copolymers are desired.”

May combine two claims.

These transition triads do not signal transesterification because for PLA-b-PCL-b-PLA the CapCapLL and CapLLLL triads matching the transition between the blocks are exclusively found.

“These triads do not signal transesterification because for, e.g., the PLA‐b‐PCL‐b‐PLA (Figure 3A) the CapCapLL and CapLLLL triads matching the transition between the blocks are exclusively found.”

May combine two claims.

Both microstructures, blocky and highly dispersed, are obtained in a solvent-free process, which is only possible due to the high robustness of the complex.

“Both microstructures, blocky as well as highly dispersed, are obtained in a solvent‐free process which is only possible due to the high robustness of the complex.”

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

The increase of transesterifications if Cap is present in the copolymerization mixture was reported for some other catalysts but never investigated in detail.

“The increase of transesterifications if Cap is present in the copolymerization mixture was reported for some other catalysts but never investigated in detail.[ 21b , 23a ]”

• cites [21b, 23a]Not checked yet

  Not checked in the free run.

May combine two claims.

The presented catalyst strongly supports transesterifications during the insertion of Cap, adds GG and LL sequentially in a controlled manner, and does not scramble two already formed polymer chains significantly by transesterification.

“It strongly supports transesterifications during the insertion of Cap on the one hand and on the other hand adds GG and LL sequentially in a controlled manner as well as it does not scramble two already formed polymer chains significantly by transesterification.”

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

The tendency of an active chain end to promote transesterification with the existing polymer chain and the preferred attack of a certain monomer depends on the nature of the catalyst.

“The tendency of an active chain end to promote transesterification with the existing polymer chain and the preferred attack of a certain monomer, was shown to depend on the nature of the catalyst.[ 21c , 33 ]”

• cites [21c, 33]Not checked yet

  Not checked in the free run.

May combine two claims.

The short sequence lengths and randomness factors close to 1 would classify the copolymers as random, while the T II values, especially for the tercopolymers, show deviations from Bernoullian statistics for LL.

“The short sequence lengths and randomness factors close to 1 would classify the copolymers as random, the T II values especially for the tercopolymers on the other hand show deviations from the Bernoullian statistics for LL.”

May combine two claims.

The mechanism of synthesis of random copolymers by transesterification must be revised: reorganization does not take place between two polymer strands exchanging chains; instead, Cap as monomer induces transesterification as active chain end, reorganizing the polymer chains nearly every time it is incorporated.

“This experimental finding implies a revision of the mechanism of the synthesis of random copolymers by transesterification: The reorganization of the polymer chains does not take place between two polymer strands exchanging chains, instead Cap as monomer induces transesterification as active chain end reorganizing the polymer chains nearly every time it is incorporated.”

May combine two claims.

The repeating units are highly dispersed along the copolymer chain in a random-like manner, with some curtailments for LL.

“Nevertheless, it can be concluded that the repeating units are highly dispersed along the copolymer chain in a random‐like manner with some curtailments for LL.”