生物可降解聚丁二酸/苯基丁二酸丁二醇酯系列共聚物的合成及其结晶行为

合成了一系列聚丁二酸/苯基丁二酸丁二醇共聚酯(PBSBS),利用DSC、1H-NMR和X射线等测试手段对共聚物组成、热力学性能、结晶性能、等温结晶行为进行了表征和研究.结果表明,含苯基的共聚单元的引入显著改变了聚丁二酸丁二醇酯(PBS)的热力学性能4,利用Hoffman-Week曲线得到的共聚物平衡熔点随共聚组分含量的增加显著降低,玻璃化转变温度则明显升高,结晶熔点符合无规共聚物的Flory方程.此外,利用Avrami方程对均聚物PBS以及共聚物PBSBS-10分别进行了等温结晶行为研究,结果表明共聚使结晶速率降低,PBS和PBSBS-10的Avrami指数分别介于2.8~3.0和2.7~2.9之间,结晶方式为三维生长异相成核,X射线测试结果表明共聚不影响晶体结构.

SYNTHESIS AND CRYSTALLIZATION BEHAVIOR OF BIODEGRADABLE POLY(BUTYLENE SUCCINATE-co-BUTYLENE PHENYLSUCCINATE)

A series of polyesters PBSBS,poly(butylene succinate-co-butylene phenylsuccinate),were synthesized from the polycondensation of succinic acid and phenylsuccinic acid with 1,4-butanediol.The compositions and thermal properties of resulted homopolyesters and copolyesters were investigated by()~1H-NMR,differential scanning calorimetry(DSC)and X-ray diffraction.The results suggested that the introduction of the comonomer containing a phenyl side-group led to a change in thermal properties and crystallization behavior.The glass transition temperature increased with the increasing of the comonomer composition,while the equilibrium melting temperature obtained by the Hoffman-Weeks plot decreased significantly.Furthermore,an Avrami method was used to analyze the kinetics of isothermal crystallization of PBS and PBSBS-10.The Avrami exponents,estimated by Avrami plots,ranging from 2.8 to 3.0 for PBS and 2.7 to 2.9 for PBSBS-10,indicated that the mechanism of crystallization for both homopolyester and copolyester was a tridimensional growth with heterogeneous nucleation.Meanwhile,X-ray diffraction showed that there was almost no effect of the phenyl succinate unit on the crystal structure.