对A型氯化聚乙烯原料结构及形态的分析

Characterization of structures and morphologies of A-type chlorinated polyethylene raw materials

采用GPC、(13)~C NMR、DSC、SEM、压汞法等方法对进口A型氯化聚乙烯(CPE)原料进行了表征,研究了CPE原料的结构和形态对原料氯化性能的影响,以期为国内厂家开发性能更加优异的CPE原料提供理论依据。实验结果表明,当原料的片晶厚度和结晶度较低时,有利于氯的扩散及氯化反应的发生,因此应适度提高原料分子链的支链含量和相对分子质量。此外,原料外表面聚乙烯小球的烧结程度也是决定原料氯化性能的主要因素,因此应降低聚合反应的放热程度。相对而言,原料的孔体积、孔径和比表面积对原料氯化性能的影响稍弱。

GPC,13C NMR,DSC,SEM and mercury intrusion methods were used to characterize the imported A type chlorinated polyethylene(CPE)raw materials,and the effects of their structure and morphology on the chlorination properties of raw materials were studied.It provides theoretical basis for domestic manufacturers to develop CPE materials with better performance.The results show that when the lamellar thickness and crystallinity of raw materials are low,it is conducive to the diffusion of chlorine and the occurrence of chlorination.Therefore,the branched chain content and relative molecular mass of raw materials molecular chain should be moderately increased.In addition,the sintering degree of the polyethylene pellets on the outer surface of the raw materials is also the main factor determining the chlorination performance.Therefore,the degree of heat release of the polymerization should be reduced.In comparison,the influence of pore volume,pore size and specific surface area on the chlorination performance of CPE raw materials were relatively weak.