4A沸石对PVC的热稳定作用特性与机理  

Characteristics and mechanism of heat stabilization of PVC by 4A zeolite

作　　者：吴茂英[1] 林莅蒙[1] 

机构地区：[1]广东工业大学轻工化工学院,广东省广州市510006

出　　处：《合成树脂及塑料》2014年第2期33-36,53,共5页China Synthetic Resin and Plastics

基　　金：科技部科技型中小企业技术创新基金项目(08C26213600946)

摘　　要：用烘箱变色法研究了4A沸石对聚氯乙烯(PVC)的热稳定作用。结果表明:4A沸石是一种长效型热稳定剂,与硬脂酸锌(ZnSt2)并用存在协同效应,热稳定性能明显优于硬脂酸钙;用4A沸石和4A沸石/ZnSt2体系稳定的PVC的受热变色呈明显的阶跃式特征。4A沸石的独特热稳定作用特性可用以下机理合理解释:前期通过离子交换以Na+交换由PVC热降解产生的HCl中的H+或由ZnSt2转化生成的ZnCl2中的Zn2+,后期以骨架结构{[(AlO2)12·(SiO2)12]12-}中和HCl。The heat stabilization of polyvinyl chloride （PVC） by 4A zeolite was studied by oven discoloration method. The results indicate that 4A zeolite is a long-term type heat stabilizer with the heat stabilizing efficiency markedly higher than that of calcium stearate, and exhibits synergistic effect with zinc stearate （ZnSt2）; the heat discoloration of PVC stabilized with 4A zeolite and 4A zeolite/ZnSt2 shows obvious step-type characteristics. The unique heat stabilizing characteristics of 4A zeolite can be explained reasonably by the mechanism as follows： it exchanges Na＋ with H＋ of HCl produced from thermal degradation of PVC or with Zn^2＋ of ZnCl 2 transformed from ZnSt2 by ion exchange at the earlier stage, and neutralizes HCl with its skeleton structure {[（AlO2）12·（SiO2）12]^12-} at the later stage.

关 键 词：聚氯乙烯 4A沸石 热稳定剂 热稳定特性 热稳定机理 

分 类 号：TQ325.3[化学工程—合成树脂塑料工业]