Copolyesters Based on Poly(butylene terephthalate)s Containing Cyclohexyl and Cyclopentyl Ring: Effect of Molecular Structure on Thermal and Crystallization Behavior

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• 作者：T. E. Sandhya ; C. Ramesh ; S. Sivaram
• 刊名：Macromolecules
• 出版年：2007
• 出版时间：September 18, 2007
• 年：2007
• 卷：40
• 期：19
• 页码：6906 - 6915
• 全文大小：776K
• 年卷期：v.40,no.19(September 18, 2007)
• ISSN：1520-5835

文摘

In an effort to understand the role of molecular structure on the thermal properties of polyestersand copolyesters, the following polyesters were synthesized: poly(1,4-cyclohexane dimethylene terephthalate)(PCT), poly(butylene-1,4-cyclohexane dicarboxylate) (PBCD), poly(1,3-cyclopentane dimethylene terephthalate)(PCPDT), and poly(butylene-1,3-cyclopentane dicarboxylate) (PBCP). PCT and PCPDT are semicrystallinepolymers with crystallization and melting temperatures higher than poly(butylene terephthalate) (PBT). However,PBCD and PBCP have lower glass transition temperature than PBT. From these homopolymers a series of poly(butylene-co-1,4-cyclohexane dimethylene terephthalate) (P(BT-co-CT)), poly(butylene terephthalate-co-1,4-cyclohexane dicarboxylate) (P(BT-co-BCD)), poly(butylene-co-1,3-cyclopentylene dimethylene) (P(BT-co-CPDT)),and poly(butylene terephthalate-co-1,3-cyclopentane dicarboyxlate) (P(BT-co-PBCP)) random copolyesters weresynthesized for the first time, and their cocrystallization behavior was investigated using differential scanningcalorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The copolymers were found to be statisticallyrandom and crystallized in all compositions. The P(BT-co-CT) and (P(BT-co-CPDT) copolyesters exhibited typicaleutectic behavior in melting and crystallization, which indicated isodimorphic cocrystallization behavior. On theother hand, in the case of P(BT-co-BCD) and P(BT-co-PBCP) copolymers, the melting and crystallizationtemperatures showed linear dependency with composition, indicating isomorphic-like crystallization behavior.