材料期刊网

用中分子溶剂邻苯二甲酸二异辛酯（DIOP）配制不同浓度的聚氯乙烯（PVC）溶液，采用冷冻萃取法制备了解缠姑PVC试样。X射线衍射分析和热分析结果表明，与未经处理的原始PVC试样相比，解缠结后PVC的结晶能力明显增强，且随着制样溶液浓度的降低。链间解缠结程度增加，PVC的结晶能力逐渐增强，有序结构含量明显增加，但是如果制样溶液浓度太低，有序姑构含量则又有所降低。进一步发现，与采用小分子溶剂四氢呋喃（THF）形成的同浓度溶液相比，经冷冻萃取后，中分子溶剂中的高分子链更易于形成较多的有序结构。

The crystallization behaviors of freeze-extracted poly (vinyl chloride) (PVC) samples derived from varying concentration solutions in the medium-sized solvent diisooctyl phthalate (DIOP) were characterized by wideangle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). The results of the study show that, as compared with the untreated original PVC sample with chain interpenetrating and entangled, the crystallization ability of the disentangled PVC samples from DIOP are obviously enhanced and the crystallinity increases. The extent of interchain disentanglement and crystailization ability increase with the decrease of the original solution concentration, resulting in the higher content of orderly structure. However, if the concentration dropped too much, the content of orderly structone would decrease. Furthermore, the polymer chains are much more likely to form orderly structure in medium-sized solvent than in small molecules solvent tetrahydrofuran (THF). These results were discussed based on the concepts of entanglement, including topological entanglement and cohesive entanglement, and disentanglement, combined with the morphology and size of polymer chain in the medium-sized solvent.