纳米碳酸钙增韧聚氯乙烯复合材料的微结构及界面行为

选择微米、亚微米和纳米级碳酸钙增韧聚氯乙烯复合材料，研究了填料粒度对聚氯乙烯（PVC）复合材料微观结构、材料力学性能及界面行为的影响。结果发现少量CaCO3填充PVC复合材料使体系的加工流动性变好，大粒径颗粒填充PVC复合材料的流动性能更好。纳米CaCO3／PVC复合材料断面出现大量的拉丝结构。采用纳米CaCO3填充PVC可使材料产生脆韧转变，显著提高PVC复合材料的韧性；微米CaCO3对PVC基本上没有增韧作用，拉伸强度随着填充量的增加而下降，而且粒径越大拉伸性能下降的趋势也越大。引入了TPT方程的半经验参数B对不同粒径的CaCO3填充PVC复合材料的界面粘接情况进行定量描述，发现碳酸钙颗粒粒径越小，界面作用越大。

Microstructure and Interfacial Properties of CaCO3 Particle Reinforced Polyvinyl Chloride Composites

The equilibrium torque of PVC(polyvinyl chloride) composite decreased with the CaCO_3 addition;a greater reduction was noted when CaCO_3 particles of larger size were employed.SEM(scanning electron microscopy) photographs showed that the particles were well dispersed in PVC matrix and that the "silk network" structure of the fracture surface existed only in composites containing nanoparticles.Such a microstructure was the mechanism for the improved toughness of CaCO_3/PVC composites.Relative to the base PVC,the tensile strength of the composites decreased,and greater reductions were observed when larger CaCO_3 particles were employed.The observed matrix-filler interactions were well correlated by the TPT equation using a proper value for the semi-empirical B parameter.