相对分子质量及其分布对纤维级聚丙烯的力学性能和加工行为的影响  

Effect of relative molecular mass and its distribution on mechanical properties and processing behavior of fiber-grade polypropylene

作　　者：巨娟侠 吴江 李耀 周朝英 金鼎铭 

机构地区：[1]中国石油兰州化工研究中心,甘肃兰州730060

出　　处：《石化技术与应用》2011年第6期509-512,共4页Petrochemical Technology & Application

摘　　要：借助凝胶渗透色谱仪、熔体流动速率仪、电子拉力机、热重分析仪和示差扫描量热仪,研究了5种纤维级聚丙烯的相对分子质量及其分布对熔体流动指数、力学性能、热稳定性和结晶行为的影响。结果表明,随着重均相对分子质量增大,试样拉伸强度降低,断裂伸长率增大。当加工温度为200～300℃时,重均相对分子质量越低,相对分子质量分布越宽,试样热稳定性越差。在剪切速率为2 400 s-1时,随加工温度的升高,试样表观黏度呈下降趋势。在相同条件下,经过纺丝机1辊和2辊拉伸,低重均相对分子质量的线密度和断裂伸长率小于高重均相对分子质量者。The effects of relative molecular mass and its distribution on the melt flow rate,mechanical properties,thermal stability and crystallization behavior of five kinds of fiber-grade polypropylene were studied by gel permeation chromatograph,melt flow indexer,electronic tensile machine,thermal gravity analyzer and differential scanning calorimeter.The results showed that the tensile strength of samples decreased and elongation at break increased with increasing weight average relative molecular mass.The thermal stability of samples decreased with decreasing weight average relative molecular mass and widening its distribution at processing temperature 200-300℃.Polypropylene apparent viscosity dropped with increasing processing temperature at shear rate 2400s^-1.Under the same conditions,the linear density and elongation at break of polypropylene with low relative molecular mass was less than that with high relative molecular mass after stretched by one-roller and two-roller spinning machines.

关 键 词：纤维级聚丙烯 相对分子质量及其分布 力学性能 结晶行为 纺丝工艺 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]