PVC变色机理及脱色途径的探讨  

Mechanism of PVC Discoloration and Ways of Decolorization

作　　者：张师军[1] 杨冬麟[1] 

机构地区：[1]化工部北京化工研究院,北京100013

出　　处：《石油化工》1990年第7期477-483,共7页Petrochemical Technology

摘　　要：在五个动力学条件假设的基础上导出了PVC降解后的共轭双键的序列分布函数(L_1、L_2、L_n≥3),可利用该函数预测 PVC 制品的变色程度。利用 UV-谱图实测了共轭双键分布,对 PVC 的变色加以理论解释。探讨了 PVC 的脱色途径,并用 Wijii 试剂验证了可以通过加成不饱和部位来脱色的设想,同时用电脑辨色仪实测了脱色程度。An equation for sequence distribution functions respecting conjugated doublebonds in degraded PVC is derived on the base of kinetic study.It is possible touse this equation to predict the extent of discoloration(yellowing) of PVC prod-ucts.Actual distribution of conjugated double bond in PVC may be obtained usingultraviolet spectrophotometry.The mechanism of discoloration of degraded PVC isthen explained theoretically.A way for decolorization is proposed which involvesreducing the length of conjugated double bond by partial saturation via e.g.addi-tion with Wiji reagent.The extent of discolorization is measured by a computer-ized color-differentiator.

关 键 词：聚氯乙烯 变色 脱色 PVD 

分 类 号：O632.21[理学—高分子化学]