Formation of polymer crystals during polymerisation

Iguchi, Masatoshi; Kanetsuna, Hisaaki; Kawai, Tōru

doi:10.1002/pi.4980030405

Cited by 18 publications

(5 citation statements)

References 37 publications

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“…A possible explanation for truncated molecular weights is that the polymer precipitates and thus, active chain ends become less reactive. However, crystallization polymerization 32 does not always hinder propagation and is known to encourage polymerization because of the favourable crystallization enthalpy, as in the case of polyoxymethylene formation. 33 For the polymers of Table 1, note that there exists a rough correlation between polymer molecular weight and polymer melting temperature.…”

Section: Initial Polymerization Results and Characterizationmentioning

confidence: 99%

“…5). 32 In a typical run, a 2.0 g sample of OGA (Table 2, entry 17) was mixed with 0.5 wt% of the catalyst and heated to 200 °C with stirring for 2 h. Subsequently, reduced pressure of 150 mmHg was applied for 12 h. The temperature was not raised above 200 °C in order to avoid possible decomposition of PGA. After the polycondensation, GPC analysis (in HFIP) indicated a strikingly high molecular weight of M n ∼ 600 000, but this number must be juxtaposed with the solubility limits of PGA in HFIP.…”

Section: Increasing the Molecular Weightmentioning

confidence: 99%

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Polyglycolic acid from the direct polymerization of renewable C1 feedstocks

2015

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Section: Initial Polymerization Results and Characterizationmentioning

confidence: 99%

Section: Increasing the Molecular Weightmentioning

confidence: 99%

Polyglycolic acid from the direct polymerization of renewable C1 feedstocks

2015

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“…Meanwhile, the strong crystallizability derived from the high conformational regularity and strong chain-chain interactions of POM leads to the coexistence and competition of polymerization and crystallization. [55,56] Both precipitation and crystallization are exothermic processes, making the overall Gibbs free energy more negative. [24] Consequently, the monomer-polymer equilibrium is shifted toward the polymer side.…”

Section: Homo-polymerization Of Triformaldehydementioning

confidence: 99%

Ring‐Opening Polymerization of Cyclic Acetals: Strategy for both Recyclable and Degradable Materials

Shen

Chen

et al. 2023

Macromol. Rapid Commun.

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To cope with the severe plastic waste crisis, massive efforts are made to develop sustainable polymer materials whose degradation involves a disposing and decomposing to small molecule (DDM) and/or a chemical recycling to monomer (CRM) process. Polyacetals, a type of pH-responsive polymers, are degradable under acidic conditions, while highly stable under neutral and basic circumstances. As for their synthesis, the cationic ring-opening polymerization (CROP) of cyclic acetals is an elegant and promising approach, though suffering from fatal side reactions and polymerization-depolymerization equilibrium. Recent development in CRM restimulates the interest in the long-forgotten CROP method due to its inherent depolymerization characteristics. In terms of the end-of-life options, polyacetals are recyclable materials with both DDM and CRM potentials. They not only expand the scope of materials for closed-loop recycling but also help to tune the degradation properties of traditional polyesters and polyolefins. This review aims to discuss the synthesis of various polyacetals by CROP and their degradation properties from the perspectives of 1) polymerization of cyclic acetals, dioxepins, and hemiacetal esters, 2) copolymerization of cyclic acetals with heterocyclic or vinyl monomers, and 3) degradation and recycling properties of the related polymers.

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“…If macromolecules leave the reaction medium at a rate comparable with the chain propagation rate, no stacking occurs; rather, structures with extended conformations of the macromolecules are formed. 315 The so-called occlusion effect responsible for occlusion of the growing polymer chains within the `dead' polymer domains should also be taken into account. Thus, by using the `compatibilisation via polymerisation' strategy one can prepare structures with the nonequilibrium orientation of macromolecules.…”

Section: Supportmentioning

confidence: 99%

Molecular polymer–polymer compositions. Synthetic aspects

Pomogailo¹

2002

Russ. Chem. Rev.

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The main ways of improving the compatibility of The main ways of improving the compatibility of polymer ± polymer compositions containing polyolefins as one polymer ± polymer compositions containing polyolefins as one component are considered. Considerable attention is given to the component are considered. Considerable attention is given to the preparation of polyolefins in the presence of an ingredient bound preparation of polyolefins in the presence of an ingredient bound to the catalyst in the catalytic (including consecutive) polymer-to the catalyst in the catalytic (including consecutive) polymerisation of olefins. The so-called reactor blends and the synthesis isation of olefins. The so-called reactor blends and the synthesis and structure of diblock and conducting composites are described. and structure of diblock and conducting composites are described. The important role of compatibilisation of polymers of different The important role of compatibilisation of polymers of different nature with the use of a third component is pointed out. The nature with the use of a third component is pointed out. The formation mechanism of molecular compositions, the structure formation mechanism of molecular compositions, the structure and properties of the intermediate layer and the main fields of and properties of the intermediate layer and the main fields of application of synthetic polyolefin ± polymer compositions are application of synthetic polyolefin ± polymer compositions are discussed. The bibliography includes 335 references discussed. The bibliography includes 335 references. .

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Formation of polymer crystals during polymerisation

Cited by 18 publications

References 37 publications

Polyglycolic acid from the direct polymerization of renewable C1 feedstocks

Polyglycolic acid from the direct polymerization of renewable C1 feedstocks

Ring‐Opening Polymerization of Cyclic Acetals: Strategy for both Recyclable and Degradable Materials

Molecular polymer–polymer compositions. Synthetic aspects

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