高耐热性的纳米CaCO3原位聚合PVC树脂新产品

在工业化反应装置上开发成功了氯乙烯原位悬浮聚合技术，得到了新品种的高耐热性的纳米CaCO3原位聚合PVC树脂。185℃刚果红试纸变色时间试验证明，纳米复合PVC树脂热分解时间比传统产品延长了近10倍。提出的机理模型是部分纳米CaCO3粒子在原位聚合过程中发生了崩解，界面上会出现具有很高化学活性的不饱和键态结构，这使得纳米CaCO3同时具有了中和PVC分子降解过程放出的HCl、取代PVC链上不稳定氯原子、加成大分子中不饱和双键等三大热稳定功能。介绍了用傅立叶变换红外光谱(FTIR)、差示扫描量热(DSC)和透射式电镜(TEM)等手段对以上机理的验证结果。

A new kind of nano - CaCO3 in - situ polymerization PVC resin with excellent heat resisting property

An in-situ polymerization process for vinyl chloride in a commerical reactor was (developed) successfully,and a new kind of nano-CaCO_3 in-situ polymerization PVC resin with excellent heat resisting property was obtained.Experiments on the transition time of Congo red test paper showed that the thermal decomposition time of nano-PVC composite resin was nearly ten times longer than that of traditional PVC resin.The proposed mechanism regarded that some nano-CaCO_3 particles disintegrated during the in-situ polymerization process and some unsaturated bond structures with high chemical activities would formed on the interfaces,which made nano-CaCO_3 have the following three kinds of heat stabilizing effects:(1)neutralizing the HCl released from the degradation of PVC molecules;(2)substituting the unstable chlorine atoms in PVC molecular chain;(3)addition reacting with the unsaturated double bonds in large molecules.This mechanism was verified by means of FTIR,DSC and TEM and the results was introduced in this paper.