一种断裂的PVC片材的微观结构研究

Study on Microstructure of a Fractured PVC Slice

对不会断片 (F)和会断片 (G)两种塑料片材的成份、微观织态结构、结晶度、热和机械性能用FT IR、X射线萤光光谱仪、TEM、XRD、热分析仪和拉力实验机进行对比研究。结果表明 :1)F和G的成份都是聚氯乙烯树脂 ,含酯增塑剂和少量添加剂 ;2 )F颗粒尺寸在 16 5nm～ 34nm之间 ;3)G的颗粒尺寸在 1μm～ 6 5nm之间 ,最大与最小颗粒尺寸相差 15倍。文中对PVC薄片迅速断裂的机理进行了讨论 ,认为G迅速断裂是由于增塑剂含量少而加工温度又低 (<190℃ )造成的。

The unfractured plastics slice(F) is contrasted with fractured plastics slice(G) in compositions, microstructures, crystallinity, thermal and mechanical properties by FT IR and X ray fluorometer TEM, XRD thermal analysis and tension test instrument. The result showed that 1) They consist of PVC resin, the plastifier and a little additive. The plastifier quantity of F is 15.5%. The plastifier quantity of G is 7.83%.2) Grains sizes of F are betwwen 165 nm～34 nm. They are in same grains of regional structure. Crystallinity of F is 5.6%. The soft point of F is 56.5 ℃. Heat decomposition of F is 261.1 ℃. Tensil strength of F are 67.24 Mpa(Horizontal) and 64.25Mpa (Horizotal).3) The grain sizes of G are between 1 μm～65 nm. The biggest grain size of G is 15 times as big as least grain size. They are between the initial grains and grains of regional structure. The crystallinity of G is 21%. The soft point of G is 70.6 ℃. The heat decomposition of G is 277.5 ℃. The tensil strengths of G are 52.69 Mpa ( Vertical) and 45.78Mpa (Horizontal). In this paper, we have a discussion on the fractured mechanism of PVC slice. We think the fracture of PVC slice is caused by less plastifier and lower processing temperature (t<190 ℃).