【摘要】 介绍一种探查已损坏的PVC薄片脆断机制的方法.用FT-IR,X射线萤光光谱仪,X射线衍射(XRD)仪,热分析仪,拉力试验机及扫描电子显微镜(SEM)对易断的PVC片材(A)和不断的PVC片材(B)的组成,结晶度,软化点,力学性能及表面形态进行对比研究.研究表明:①A和B都是由PVC树脂,含酯增塑剂以及少量有机锡、含硫的光、氧稳定剂及TiO2的白色遮盖剂组成的多元复合体系[1].不同的是增塑剂质量分数[2]A是10.42%,B是15.5%;②A的结晶度是13.3%,软化点是64.2℃;B的结晶度是5.6%,软化点是56.5℃;③A的织态结构是高度取向的且在平行取向方向存在小于1μm的多条细裂纹.其纵向抗张强度是55.38%,横向抗张强度为41.6MPa;④B是"毛毯"织态结构.其纵向抗张强度是67.24MPa,横向抗张强度是64.25MPa.文中对A类片材断裂的机理进行了讨论.该片材主要是本体材料塑化不好又进行单向过渡取向造成.更多还原

【Abstract】 Introduced a method of probing brittle fracture mechanism of damaged PVC slice.The fractured PVC slice (A) is contrasted with unfractured PVC slice (B) in compositon,crystallinity,soft point,mechanical properties and surface form by FT-IR,X-ray fluorometer,XRD,thermal analysis instrument,tensile test bed and SEM.The research showed that ① Both of A and B consist of PVC resin, plastifier and a little additive. The plastifier quantity of A is 10.42%.The plastifier quantity of B is 15.5%.② The crystallinity of A is 13.3%.The soft point of A is 64.2℃;The crystallinity of B is 5.6%.The soft point of B is 56.5℃.③ Wearing state structure of A is elevation orientation.There are cracks less than 1?μm .Their directions are parallel to the slice orientation.Vertical tensil strength of A is 55.38?MPa.Horizontal tensil strength of A is 41.6?MPa.④ Wearing state structure of B is "woolen blanket".The vertical tensil strength of B is 67.24?MPa.The horizontal tensil strength of B is 64.25?MPa. In this paper,we have a discussion on the fractured mechanism of PVC slice.The fracture of PVC slice is caused by bad plastication and the elevation orientation of these slices.The elevatio orientation of these slices is caused by one way tension.更多还原