不同聚氯乙烯(PVC)树脂的流变行为及其形态变迁

研究了160—200℃之间的不同PVC树脂流变行为,并用扫描电子显微镜观察其形态变迁。不同形态PVC的η′—1/T关系表明在190℃处流动机构存在转折,电镜形态照片证明:在190℃以下,PVC的流动单元主要是～1μ的基本颗粒及其集合体;在190℃以上,PVC的流动单元为～0.05μ的次基本颗粒,而在190℃时,～0.05μ的次基本颗粒已是主要的结构形态。当PVC的流动单元为次基本颗粒时,η′随温度的增加而增加。

RHEOLOGICAL BEHAVIOUR AND MORPHOLOGICAL CHANGES OF DIFFERENT POLYVINYLCHLORIDE(PVC) RESINS

The rheological behaviour of different PVC resins between 160℃and 200℃ have been studied, their changes in morphology were observed by scanning electron microscopy.The relation of η'-I/T of PVC with different morphology shows the existence of a transition in flow mechanism at 190℃, morphological photographs of scanning electron microscopy gave direct evidence in following sequence: -1μ primary particles and their agglomerates are main flow units in PVC below 190℃, but - 0.05 ℃ sub-primary particles are the flow units in PVC above 190℃ and - 0.05 ℃ sub-primary particles are already main structural morphology at 190℃. η' increases with temperature when sub-primary particles are the flow units in PVC.