Mesomorphic Structures of Blended Biodegradable Polymers and their Morphologies

点击翻译按钮获取中文摘要

Biodegradable polymers includes the group of synthesized aliphatic polyesters and natural cellulose. In recent years these polymers are very much interested in preventing from environmental pollutions. Especially the aliphatic polyesters are recognized in their availability by various industries. The purpose of this research is to investigate the fine structures of several kinds of biodegradable polymers, poly(L-lactide) (PLLA), poly(ε-caprolactone)(PCL), poly(ethylene succinate) and also their polymer blends.The results obtained are summarized as follows:(1) We established the special method in forming transcrystal (TC) films of PLLA, which had been sandwiched between two Teflon sheets during isothermal crystallization. In the TC structures of the polymers, the lamellar growth occurs mainly in the direction to the center of films.(2) The TC films could be dawn to the maximum draw ratio ofXI0. This good drawability is somewhat different from those films composed of 3-dimentionally deve … More loped spherulites. A kind of shish-kebab structures were observed on the drawn TC film surfaces.(3) The trial was made to obtain the isolated shish-kebab structure of the PLLA by 'dilute solution crystallization techniques under shearing forces. Morphological features related to the shishi-kebab structures were confirmed by transmission electron microscopy. However we could not obtain the ED patterns from those solution grown precipitants.(4) We also tried to form the TC structure of PLLA/PCL blends where their mixing ratio were changed in various values. It was very difficult to obtain the TC films from the blend polymers. Some surface factors were anticipated to influence the formation of nuclei in the blended films.(5)The crystallization kinetics studies were performed in the blended films using DSC apparatus. The works along this line will be continued in future as well as the TC structure formation.(6) Solution grown crystals of poly(ethylene succinate) could be obtained in this study. We examined their morphologies and ED patterns to determine the lattice constants. Less