紫外光辐照对软质聚氯乙烯结构及性能的影响

Effect on Ultraviolet Irradiation on Structure and Properties of Soft Poly(vinyl chloride)

采用表面衰减全反射傅立叶变换红外光谱(ATR-FTIR)、凝胶渗透色谱(GPC)、扫描电镜(SEM)、力学性能测试等方法研究了紫外光(UV)辐照对邻苯二甲酸二辛酯(DOP)增塑的软质聚氯乙烯(PVC)结构及性能的影响。结果表明,随着UV辐射时间的延长,分子链中引入了多种羰基官能团。数均分子量逐渐降低,重均分子量和Z均分子量先增大后逐渐减小,相对分子质量分布变宽。试样表面经历了粗糙、裂纹形成等形态破坏过程。UV辐照初期,试样的拉伸强度和断裂伸长率变化较小,进一步延长辐照时间,两者均显著降低。

Effect on ultraviolet light （UV） irradiation on the structure and properties of soft PVC was studied by means of ATR-FTIR, GPC, SEM and mechanical properties tests. With UV irradiation time increasing, the carbonyl groups were generated on PVC＇s molecular chains. The number-average molecular weight of PVC decreased constantly. The weight-average molecular weight and Z-average molecular weight increased to a maximum then decreased, molecular weight distribution broadened. Surface of PVC samples became coarse and cracks formed. The tensile strength and elongation at break of PVC samples changed slightly at initial stage, and then decreased.