基于拉伸流变的叶片塑化挤出PP/纳米CaCO_3复合材料的结构与性能

Study on structure and properties of PP/nano-CaCO_3 composites prepared by vane plasticizing extruder based on tensile rheology

针对传统基于剪切流场的螺杆挤出设备对填充改性复合材料性能提升空间有限的问题,采用基于体积拉伸流变的新型叶片塑化挤出机加工制备PP/纳米CaCO3复合材料。在产量、温度、填充配比等加工参数一致的前提下,对叶片塑化挤出试样与传统双螺杆加工试样的力学性能、流变特性、结晶性能、微观形貌进行对比测试分析。研究结果表明：相对于螺杆挤出加工的PP/纳米CaCO3复合材料,相同配比的叶片挤出制品的拉伸强度能提高10%~15%,表观剪切黏度增大,结晶度提高9%~27%;SEM照片显示微观纳米粒子尺度均一,分散更均匀。基于拉伸形变作用的叶片塑化挤出加工能更充分地发挥PP/纳米CaCO3复合材料微观粒子的增强、增韧效果。

Aiming at the problem of limited improvement of property of filling modification composites using traditional screw extruder based on shear flow field,a novel vane plasticizing extruder based on volume tensile rheological mechanism was introduced to prepare polypropylene（PP）/nano-CaCO3 composites.And the mechanical,rheological,crystallization properties and microstructure of the PP/nano-CaCO3 composites were investigated and compared with the samples produced by traditional twin-screw extruder when the processing parameters such as production,temperature,filler ratio and so on were the same.The results show that compared with samples produced by screw extruder,the tensile strength of PP/nano-CaCO3 composites prepared by vane extruder increases by 10%to 15%;the apparent shear viscosity increases;and the crystallinity increases by 9%to 27%.SEM images show that the nanoparticles have similar sizes and are more uniformly dispersed.Therefore,the vane plasticizing extruder processing based on tensile deformation can more fully exert the reinforcing and toughening effect of PP/nano-CaCO3 composite microscopic particles.