不同链结构的双酚A聚碳酸酯对脂肪族聚碳酸酯结晶行为的影响

脂肪族聚碳酸酯(APC)是一类可降解的高分子材料,因其生产工艺可固定温室气体的主要成分二氧化碳,这种可降解塑料得到了越来越多的关注.作为半结晶高分子材料,脂肪族聚碳酸酯的结晶性能和结晶结构对成型加工、力学性能和降解性能具有重要的影响.借助热分析(示差扫描量热仪DSC)和形态学观察(偏光显微镜POM)两种方法研究了不同链结构的双酚A型聚碳酸酯对半结晶脂肪族聚碳酸酯——聚碳酸1,4-丁二醇酯结晶动力学行为的影响.实验发现质量分数1%的双酚A聚碳酸酯的加入促进了聚碳酸1,4-丁二醇酯的成核,但不同链结构的双酚A聚碳酸酯对其晶体生长具有相反的作用,线形双酚A聚碳酸酯(PC-L)能够促进晶体生长,而支化双酚A聚碳酸酯(PC-B)则抑制晶体生长.用原子力显微镜在轻敲模式下研究了两种双酚A聚碳酸酯与APC共混物熔融状态下的相结构,发现熔体结构的不同是导致两种共混物与纯的APC相比,结晶速率呈现相反变化趋势的主要原因.

EFFECT OF BISPHENOL A POLYCARBONATE WITH DIFFERENT CHAIN STRUCTURE ON THE CRYSTALLIZATION BEHAVIOR OF ALIPHATIC POLYCARBONATE

In the present investigation,the effect of the chain structure and aggregation state of bisphenol A polycarbonate(PC) on the crystallization kinetics and morphology of the poly(butylene carbonate) has been studied by DSC and POM.It was found that the addition of bisphenol A polycarbonate A promoted the nucleation of the poly(butylene carbonate),while the chain structure of PC had the opposite influence on the crystal growth rate of the poly(butylene carbonate).The linear bisphenol A polycarbonate polycarbonate accelerates the crystal growth rate of poly(butylene carbonate),while the long chain-branched bisphenol A polycarbonate decelerates it.The phase images of the blends of aliphatic polycarbonates and bisphenol A polycarbonate were obtained under the tapping mode by atomic force microscopy(AFM).The linear bisphenol A polycarbonate shows isolated irregular aggregation with phase size of ca.200 nm in the poly(butylene carbonate),while the formation of condense and continuous network structure by long branched bisphenol A polycarbonate might explain the deceleration effect on the crystal growth rate of the poly(butylene carbonate).