同步辐射原位研究构象有序对高分子结晶的影响

项目名称： 同步辐射原位研究构象有序对高分子结晶的影响

项目编号： No.51303166

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 李向阳

作者单位： 中国科学院合肥物质科学研究院

项目金额： 25万元

中文摘要： 旋节线相分离辅助结晶被认为是一种重要的高分子结晶机制，但一直未得到实验证实。均相成核可以使得高分子在低温下生成更多构象有序链段，从而有利于揭示构象有序与晶体有序的关系。本项目拟利用同步辐射显微红外和微聚焦X射线衍射研究置于无规聚苯乙烯基底的等规聚丙烯微球在均相成核过程中构象有序和晶体结构演化过程。通过观察构象有序在小球内空间分布，检测结晶前高分子熔体中是否存在构象有序在某些区域内的富集现象。同时研究聚丙烯中间相残留分子构象对结晶动力学的影响，揭示构象有序与晶体有序的相互关系。本研究能够给出高分子在均相成核过程中构象和晶体结构的演化，这是以前研究不能给出的，是近年来同步辐射显微技术和微聚焦的发展才有可能实现的。这项研究有可能加深人们对于高分子结晶前期的认识，并为调控预有序结构来制备性能更好的高分子材料积累经验。

中文关键词： 构象有序；结晶机理；取向有序；等规聚丙烯；记忆效应

英文摘要： Spinodal-assisted crystallization is believed to be a promising physical mechanism of polymer crystallization. However, it has not been experimentally confirmed yet. Homogeneously nucleation allows more conformational chains formed without crystallization, which can be used to clarify the relationship between crystallization and conformation ordering. In this project, changes in corformational ordering and crystalline structure are monitored during homogeneous crystallization of isotactic polypropylene micro-droplets which are placed in the atactic polystyrene matrix using synchrotron radiation infrared microspectroscopy and X-ray microdiffraction. Through monitoring space distribution of corformational ordering, it is tested that if conformational ordering polymer chains aggregate prior to crystallization. This study will also investigate the influence of confornational ordering on crystallization behaviour after heating iPP mesophase at tempertures slightly above melting point in order to remain corformational ordering. Through this study, we aim to illustrate the relationship between corformational ordering and crystalline structure.This study takes full advantage of synchrotron radiation infrared microspectroscopy and X-ray microdiffraction,giving structural information during homogeneous crystallization, wh

英文关键词： Conformation ordering；Crystalline machanism；Orientation ordering；isotactic polypropylene；Memory effect