高分子量聚氯乙烯的形态,流变与加工性能

采用程序升温Ｂｒａｂａｎｄｅｒ转矩－流变仪研究，比较了两种高分子量聚氯乙烯树脂（分子量相同）及其增塑体系在相同剪切应力作用下的熔融过程。采用毛细管流变仪和Ｂｒａｂａｎｄｅｒ挤出－流变仪研究了上述增塑体系的流变行为和挤出性能。结果表明，树脂颗粒的疏松程度越好，颗粒表面无皮膜包覆，粉粒破碎成聚结体和初级粒子的温度越低，这些微观层次的粒子相互粘连直至形成分子熔体的熔融温度越低，其增塑体系的熔融温度也越低

THE MORPHOLOGY,RHEOLOGY AND PROCESSING PROPERTIES OF HIGH MOLECULAR WEIGHT POLY(VINYL CHLORIDE)

The Brabander torque-rheometer with proprammable elevating temperature was used to study and compare the melting processes of two high molecular weight poly(vinyl chloride) resins(each having same molecular weight) and their plasticized systems in same shear stress.The capillary rheometer and Brabander extrution-rheometer were applied to study the rheological behaviour and extruded properties of above plasticized systems. The results illustrate that the looser particle structure of the resins,the lower temperature to breaking the grain into agglomerate and primary particle as well as of sticking these microscopic particle together until the molecular melt is formed,and the lower melting temperature and faster rate of extrusion of their plasticized systems.The results the show that when increasing shear rate, the particle morphology of resins is looser,the apparent viscosity is markedly dropped .