PBT/BA-MMA-AA三元共聚物共混物的结晶行为和结晶动力学

考察了聚对苯二甲酸丁二醇酯(PBT)／“壳-棱”型丙烯酸丁酯-甲基丙烯酸甲酯-丙烯酸三元共聚物(BA-MMA-AA)共混物的熔融和结晶行为。研究显示，BA-MMA-AA含量较低时，BA-MMA-AA中羧基对PBT分子链的干扰导致了共混物中PBT的熔点和结晶度下降；随BA-MMA一从含量的提高，其异相成棱作用导致PBT的成棱速率和结晶速率提高，从而提高了共混物中PBT的熔点和结晶度．采用Avrami方程分析了试共混物的等温结晶动力学参数，发现共混物的结晶速率常数K显著变小，最大结晶速率时间tmax和半结晶时间t1/2均变短，表明加入BA-MMA-AA使PBT的成棱速率和结晶速率得到提高。

STUDY ON CRYSTALLIZING BEHAVIOR AND CRYSTALLIZATION KINETICS OF PBT/BA-MMA-AA COPOLYMER BLENDS

A core-shell type methyl methacrylate-butyl acrylate-acrylic acid copolymer (BA-MMA-AA) was employed to blend with poly(butylene terephalate) (PBT), and the crystallizing behavior and crystallization kinetics of the blends were studied. The non-isothermal melting and crystallizing DSC diagrams demonstrated that the effect of acid group of BA-MMA-AA at low content resulted in a decrease of the melt point and the degree of crystallinity of PBT. However, the nucleating effect of BA-MMA-AA at high content increased the nucleating and crystallizing rate, and then achieved improvement of the melt point and the degree of crystallinity of PBT. The crystallization parameters were deduced from Avriami equation. It is found that the crystallization rate constants, the time at maximum crystallization rate, and the time at half crystallization course decrease with the increase of BA-MMA-AA content, which constitute the evidence of nucleating effect of BA-MMA-AA.