Synthesis and thermal characterization of crystallizable poly(caprolactone)/poly(hexamethylene terephthalate) block copolymer

Lefevre, C.; Villers, D.; Koch, Michel H. J.; David, Christiane

doi:10.1016/s0032-3861(01)00362-7

Cited by 19 publications

(16 citation statements)

References 30 publications

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“…The wide‐angle X‐ray diffraction (WAXS) results are presented in Figure 9. The presence of only one crystalline system, ortho ‐rhombic was reported for poly(ε‐caprolactone) 47. Based on X‐ray diffraction data, the unit cell of poly(MDI‐BD) is triclinic with dimensions a = 5.33 Å, b = 5.26 Å, c = 38.68 Å, α = 113.6, β = 116.0, γ = 94.4 degrees 48.…”

Section: Resultsmentioning

confidence: 98%

Synthesis and characterization of novel urethane‐siloxane copolymers with a high content of PCL‐PDMS‐PCL segments

Pergal

Antić

Govedarica

et al. 2011

J of Applied Polymer Sci

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Novel polyurethane copolymers derived from 4,4 0 -methylenediphenyl diisocyanate (MDI), 1,4-butanediol (BD) and a,x-dihydroxy-[poly(caprolactone)-polywere synthesized by a two-step polyaddition reaction in solution. In the synthesis of the polyurethanes, the PCL blocks served as a compatibilizer between the nonpolar PDMS blocks and the polar comonomers, MDI and BD. The synthesis of thermoplastic polyurethanes (TPU) with high soft segment contents was optimized in terms of the concentrations of the reactants, the molar ratio of the NCO/OH groups, and the time and temperature of the polyaddition reaction. The structure, composition, and hard MDI/BD segment length of the synthesized polyurethane copolymers were determined by 1 H, 13 C-NMR, and two-dimensional correlation (COSY, HSQC, and HMBC) spectroscopy, while the hydrogen bonding interactions in the copolymers were analyzed by FT-IR spectroscopy. The influence of the reaction conditions on the structure, molecular weight, thermal, and some physical properties was studied at constant composition of the reaction mixture. A change in the molar ratio of the NCO/OH groups and the reaction conditions modified not only the molecular weight of the synthesized polyurethanes, but also the microstructure and therefore the thermal and physical properties of the copolymers. It was demonstrated that only PCL segments with high soft segment contents crystallize, thereby showing spherulitic morphology.

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Section: Resultsmentioning

confidence: 98%

Synthesis and characterization of novel urethane‐siloxane copolymers with a high content of PCL‐PDMS‐PCL segments

Pergal

Antić

Govedarica

et al. 2011

J of Applied Polymer Sci

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“…Nevertheless, PHT continues exhibiting good mechanical properties and chemical resistance characteristic of aromatic polyesters [17]. PHT is not biodegradable, and as it happens with other poly(phthalate)s, block copolyesters of hexamethylene terephthalate (HT) and -caprolactone have been explored for their potential as biodegradable materials for packaging [18]. Recently we succeeded in preparing copolyesters of HT and ε-caprolactone (CL) by ROP.…”

Section: Introductionmentioning

confidence: 99%

Poly(hexamethylene terephthalate-co-caprolactone) copolymers: Influence of cycle size on ring-opening polymerization

González-Vidal

Ilarduya

Muñoz‐Guerra

2010

European Polymer Journal

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Poly(hexamethylene terephthalate) was cyclo-depolymerized in solution by heating to yield a fraction of cyclic oligomers of hexamethylene terephthalate (c(HT) 2-5 ) with a content around to 95% in dimer to pentamer. Ring-opening polymerization in the melt of c(HT) 2-5 , either neat or in mixtures with ε-caprolactone (CL) covering a range of HT/CL ratios from 9/1 to 1/9 was carried out to produce polyesters with molecular weights above 30,000 in high yields. The copolyesters had a comonomer composition according to the feed and the microstructure evolved from random to blocky as the content in CL increases. The thermal and mechanical properties of the copolyesters were evaluated for a variety of compositions. Results obtained in this work were compared to those previously obtained by us in the ring-opening copolymerization of CL with a cyclic oligomeric fraction enriched in hexamer and heptamer (c(HT) 6-7 ). Although the polyesters resulting from the use of these two fractions were similar, significant differences were found in polymerization rate evidencing a lower reactivity of c(HT) n with decreasing values of n.

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“…In addition, an oligomeric PHT and its copolymers with poly(e-caprolactone) (PCL) and poly(hexamethylene 2,6-naphthalate) (PHN) have been shown to exhibit a number of sharp melting peaks upon DSC heating. [20][21][22] However, the polymorphisms and multiple melting peaks in PHT, and their possible correlation with unit-cell crystal forms, have yet to be fully understood, and the possible structure transformation in PHT during melt-crystallization and subsequent heat scanning or annealing is still unclear and unidentified. Moreover, the spherulitic morphology of melt-crystallized PHT has not yet been explored.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Polymorphism and Dual Crystalline Morphologies in Poly(hexamethylene terephthalate)

Woo

Chiang

et al. 2004

Macromol. Rapid Commun.

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Summary: The polymorphisms in poly(hexamethylene terephthalate) (PHT), along with their associated melting and spherulite morphologies, were examined by differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), and polarized‐light microscopy (PLM). The morphology and crystal cells were dependent on the temperature of crystallization. When melt‐crystallized at low temperatures (90–135 °C), PHT showed at least five melting peaks and two re‐crystallization peaks upon DSC scanning, and the samples displayed various fractions of both α and β crystals. However, only a single melting peak was obtained in PHT melt‐crystallized at 140 °C or above, which displayed a single type of β crystal. In addition, two different forms of spherulites were identified in melt‐crystallized PHT, with one being a typical Maltese‐cross spherulite containing the α crystal, and the other being a dendrite‐type packed mainly with the β crystal. This study provides timely evidence for a critical interpretation of the relationship between multiple melting and polymorphisms (unit cells and spherulites) in polymers, including semi‐crystalline polyesters.

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Synthesis and thermal characterization of crystallizable poly(caprolactone)/poly(hexamethylene terephthalate) block copolymer

Cited by 19 publications

References 30 publications

Synthesis and characterization of novel urethane‐siloxane copolymers with a high content of PCL‐PDMS‐PCL segments

Synthesis and characterization of novel urethane‐siloxane copolymers with a high content of PCL‐PDMS‐PCL segments

Poly(hexamethylene terephthalate-co-caprolactone) copolymers: Influence of cycle size on ring-opening polymerization

Analysis of Polymorphism and Dual Crystalline Morphologies in Poly(hexamethylene terephthalate)

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