薄膜级聚丙烯熔体流变行为的研究

Study on melt rheological behavior of film grade polypropylene

采用熔体流动速率仪、凝胶色谱仪、毛细管流变仪、熔体拉伸流变仪、旋转流变仪等分析仪器,研究了3个薄膜级聚丙烯(PP)样品的熔体流变行为。结果表明,样品的重均相对分子质量由大至小的顺序依次为PP 1,PP 2,PP 3,相对分子质量分布由宽至窄的顺序依次为PP 3,PP 2,PP 1,剪切黏度和熔体强度由高至低的顺序依次为PP 1,PP 2,PP 3;聚合物的相对分子质量越大,其剪切黏度和熔体强度越高,加工性能越差。

The melt rheological behavior of three film grade polypropylene（ PP） samples were studied with analysis instruments including melt flow rate apparatus,gel permeation chrommatograph,capillary rheometer,melt extensional apparatus and rotary rheometer. The results showed that weight- average relative molecular mass of three PP samples in order from large to small were PP 1,PP 2,PP 3,the distribution of relative molecular weight in turn from wide to narrow were PP 3,PP 2,PP 1,and the shear viscosity and melt strength in sequence from high to low were PP 1,PP 2,PP 3. The larger relative molecular weight of polymer was,the higher its shear viscosity and melt strength were and the worse its processing ability was.