长链支化聚丙烯的流变性能研究

利用反应挤出法制备了长链支化聚丙烯,采用旋转流变仪和毛细管流变仪对纯聚丙烯及其改性聚丙烯进行测试,用流变学理论进行表征。结果表明,聚丙烯加入支化剂后,产生了长支链,分子量增大,分子量分布变宽;在一定范围内,随着支化剂量的增大,其支化程度增加;在低频处,能模量G'比损耗模量G″对长支链的出现及量变更敏感;加入支化剂后熔体强度明显增大,且支化的程度越高熔体强度越大,可拉伸性变小,能有效地改善材料的加工性能。

Research on Rheology Properties of Long Chain Branched Polypropylene

The long chain branched polypropylene was achieved by reactive extrusion method. The pure polypro-pylene （PP） and modified PP were tested by rotary rheometer and capillary rheometer, and were characterized with rheological theory. The results has been proved that the polypropylene produced a long branches chain, the molecular weight was increased and the molecular weight distribution was broadened by using branched agent. Within the limits of a certain range, It was also found that the degree of branching was increased along with the increase of branched agent. The G＇ was highly sensitive than G＇ to the degree of branching at low frequency. There is a higher melt strength of polypropylene by using branched agent, the higher degree of branching the higher melt strength while the tensile strength was decreased. It can effectively improve the processing performance of materials.