Chain conformation in medium- and high-ester content polyether-polyester block copolymers: a small-angle neutron scattering study

Miller, John A.; McKenna, J. M.; Pruckmayr, G.; Epperson, J. E.; Cooper, Stuart L.

doi:10.1021/ma00151a015

Cited by 20 publications

(17 citation statements)

References 17 publications

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“…The multiple peaks evident in some of the thermograms indicate the presence of crystallites of different sizes and perfection, due to the irregularity of the length of the PBT segments or to crystal reorganization during heating. This resulted in the appearance of small exo‐ and endo‐peaks before and after the main melting peaks 27–31…”

Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of poly(ester ether siloxane)s

Vučković¹,

Antić²,

Dojčinović³

et al. 2006

Polymer International

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A series of novel thermoplastic elastomers based on ABA-type triblock prepolymers, poly[(propylene oxide)-(dimethylsiloxane)-(propylene oxide)] (PPO-PDMS-PPO), as the soft segments, and poly(butylene terephthalate) (PBT), as the hard segments, was synthesized by catalyzed two-step melt transesterification of dimethyl terephthalate (DMT) with 1,4-butanediol (BD) and α,ω-dihydroxy-(PPO-PDMS-PPO) (M n = 2930 g mol −1 ). Several copolymers with a content of hard PBT segments between 40 and 60 mass% and a constant length of the soft PPO-PDMS-PPO segments were prepared. The siloxane-containing triblock prepolymer with hydrophilic terminal PPO blocks was used to improve the compatibility between the polar comonomers, i.e. DMT and BD, and the non-polar PDMS segments. The structure and composition of the copolymers were examined using 1 H NMR spectroscopy, while the effectiveness of the incorporation of α,ω-dihydroxy-(PPO-PDMS-PPO) prepolymer into the copolyester chains was controlled by chloroform extraction. The effect of the structure and composition of the copolymers on the transition temperatures (T m and T g ) and the thermal and thermo-oxidative degradation stability, as well as on the degree of crystallinity, and some rheological properties, were studied.

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Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of poly(ester ether siloxane)s

Vučković¹,

Antić²,

Dojčinović³

et al. 2006

Polymer International

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“…The multiple peaks which occur in some thermograms indicate the presence of crystallites of different size and perfection due to the irregularity of the length of PBT segments or due to the effect of crystal reorganization which occurs during heating. This results in the appearance of small exo‐ and endo‐peaks before and after the main melting peaks 21–24…”

Section: Resultsmentioning

confidence: 99%

The effect of segment length on some properties of thermoplastic poly(ester–siloxane)s

Antić

Govedarica

Djonlagić

2003

Polymer International

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A series of novel thermoplastic elastomers, based on poly(dimethylsiloxane) (PDMS) as the soft segment and poly(butylene terephthalate) (PBT) as the hard segment, were synthesized by catalyzed two‐step, melt transesterification reactions of dimethyl terephthalate and methyl esters of carboxypropyl‐terminated poly(dimethylsiloxane)s (M̄n = 550–2170 g mol−1) with 1,4‐butanediol. The lengths of both the hard and soft segments were varied while the weight ratio of the hard to soft segments in the reaction mixture was maintained constant (57/43). The molecular structure, composition and molecular weights of the poly(ester–siloxane)s were examined by 1H NMR spectroscopy. The effectiveness of the incorporation of the methyl‐ester‐terminated poly(dimethylsiloxane)s into the copolymer chains was verified by chloroform extraction. The effect of the segment length on the transition temperatures (Tm and Tg) and the thermal and thermo‐oxidative degradation stability, as well as the degree of crystallinity and hardness properties of the synthesized TPESs, were studied. Copyright © 2003 Society of Chemical Industry

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“…Polyether acts like a soft segment, providing rubberlike properties to the terephthalic polyester. Usually, the content of the soft segment in copolymers should be more than 20 wt % to obtain TPE character, so the majority of previous studies on polyether–polyesters all focused on the properties of high‐ether‐content polyether–polyesters 2–14. Polyether–polyesters have been identified as semicrystalline‐like materials, possessing crystalline polyesters and well‐mixed amorphous polyether and polyester domains 4–7, 11.…”

Section: Introductionmentioning

confidence: 99%

Crystallization kinetics for low‐ether‐content polyether–polyester block copolymers with amide linkages

Hseih

Yang

et al. 2001

J Polym Sci B Polym Phys

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A series of low-ether-content polyether-polyester block copolymers with amide linkages were synthesized. Their crystallization kinetics and mechanisms were investigated. The crystallization kinetics were analyzed via Avrami treatment; an average value of 1.8 for the Avrami index was thus obtained. Athermal nucleation was evidenced by observations of a linear boundary between impinged spherulites under polarized light microscopy and transmission electron microscopy. The development of spherulitic morphology with a hedgehog texture was attributed to the mechanism of lamellar branching. On the basis of the morphological observations and Avrami analysis, a crystallization mechanism through a heterogeneous nucleation process with homogeneous lamellar branching was proposed. No regime transition was found for polyether-polyesters in the examined temperature ranges, and the crystallization was identified as regime I kinetics on the basis of a Lauritzen Z test. The copolymerization of poly(ether amide)s with polyesters led to a significant suppression of the crystallization rate of polyester crystals. The suppression was explained as the result of a dilution effect in nucleation combined with an increasing nucleation barrier. (C) 2001 John Wiley & Sons, Inc

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Chain conformation in medium- and high-ester content polyether-polyester block copolymers: a small-angle neutron scattering study

Cited by 20 publications

References 17 publications

Synthesis and characterization of poly(ester ether siloxane)s

Synthesis and characterization of poly(ester ether siloxane)s

The effect of segment length on some properties of thermoplastic poly(ester–siloxane)s

Crystallization kinetics for low‐ether‐content polyether–polyester block copolymers with amide linkages

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