共聚PP及PP/CaCO3高填充体系的流变行为研究

以双螺杆挤出机制备了共聚PP/CaCO₃高填充复合材料,表征了CaCO₃粒子在基体中的分散行为,并对共聚PP及复合体系的流变行为进行了研究。结果表明:纯共聚PP的熔体呈现出明显的假塑性流体行为,提高熔体温度,熔体的弹性有所增强;高填充共聚PP/CaCO₃复合体系及高填充共聚PP/HDPE/CaCO₃复合体系的熔体的剪切行为与纯共聚PP的类似,高填充的CaCO₃粒子仅对共聚熔体的表观粘度产生轻微影响;共聚PP中大量存在的CaCO₃粒子,降低了熔体的假塑性行为;提高剪切速率是调节高填充共聚PP/HDPE/CaCO3_复合体系粘度的有效手段。

Rheology and Dispersion Behavior of P ropylene-Ethylene Copolymer and Highly FilledP ropylene-Ethylene Copolymer/Calcium Carbonate Composites

The rheology and dispersion behavior of commercial propylene-ethylene copolymer, highly filled propylene-ethylene copolymer/CaCO₃ composites and highly filled propylene-ethylene copolymer/HDPE/CaCO₃ composites prepared by melt-compounding were investigated. The pure propylene-ethylene copolymer exhibits pseudoplastic flow behavior obviously. The CaCO₃ particles in the composites have achieved a homogeneous dispersion and the increasing shear rate has almost no influence on the dispersion behavior of CaCO₃ particles. The high loading of CaCO₃ particles influences the rheology behavior of propylene-ethylene copolymer slightly. For the highly filled propylene-ethylene copolymer/CaCO₃ composites, the extensional viscosity only decreases slightly throughout the entire range of extension rates.