粉末固相氯化聚乙烯结构的研究

本工作用核磁共振、红外光谱、裂解气相色谱和示差扫描量热等技术研究了粉末固相氯化聚乙烯(CPE)的结构。结果表明,在氯含量达到50%以前的氯化过程是受阻型取代机理,所得CPE的分子链主要以—CH₂—和—CHCl—基团组成;在氯含量超过50%以后,有—CCl₂—基团产生,但量极少,反应机理较为复杂。氯化后试样的结晶性能的变化不同于水相悬浮氯化的产物,亦不同于溶液氯化的产物。

A STUDY OF THE STRUCTURE OF SOLID PHASE CHLORINATED POWDER POLYETHYLENE

Several studies on the micro-and crystalline structure of solution-and suspension-chlorinated polyethylene(CPE) have appeared in literature.This paper presents our study on the structure of solid phase chlorinated powder polyethylene by means of ¹³C-nuclear magnetic resonance, infrared spectroscopy, pyrolysis-gas chromatography and differential scanning calorimetry.The results show that chlorination of the samples with low chlorine-content was hindered-type substitution,while that of the samples with chlorine content over 50 wt% seemed to be more complicated. The molecular chains of thesc CPE mainly composed of-CH₂-and-CHCl-groups; only in the samples with chlorine-content over 50 wt% appeared-CCl₂-groups, the quantity of which,however,was extremely small. The change of crystallization behavior of these CPE was different from both the solution-chlorinated and the suspension chlorinated polyethylenes.