聚丙烯/无规共聚聚丙烯共混物的流变行为与力学性能研究

Rheological Behavior and Mechanical Properties of PP/PP-R Blends

以毛细管流变仪研究了聚丙烯 (PP) /无规共聚聚丙烯 (PP R)共混物熔体的流变行为。讨论了共混物的组成、剪切应力和剪切速率以及温度对熔体流变行为、熔体粘度的影响。测定了不同配比共混物熔体的非牛顿指数和膨胀比。结果表明 :PP/PP R共混物熔体属假塑性流体 ,其熔体粘度随PP R含量的增加而迅速增大。力学性能测试结果表明 ,PP R对PP有很好的增韧改性作用。另外 ,也用偏光显微镜研究了PP R对共混物结晶形态的影响。

Rheological behavior of PP/PP-R blends was studied with a capillary rheometer. Influences of composition of the blends, shear stress , shearing rate and temperature on the rheological behavior and viscosity of the melt were discussed. Non-Newtonian index and die swell ratio of the melt with various composition of the blends were measured. Results showed that PP/PP-R blends were pseudoplastic fluid. The melt viscosity promptly increased with increasing PP-R contents. Mechanical property showed that PP-R had good toughening effect on PP. Influences of PP-R on crystallization morphology of the blends were also studied by Polarized Optical Microgrophy.