纳米级CaCO_3粒子与弹性体CPE微粒同时增韧PVC的研究

研究了平均粒径为 30nm的超细级纳米CaCO3 与氯化聚乙烯 (CPE)对聚氯乙烯 (PVC)共混体系二元协同增韧效应及机制 .结果表明 ,当共混体系中有一定量的CPE时 ,纳米CaCO3 的加入可以明显地提高共混物的韧性 ,而不降低共混物的强度和刚性 .纳米CaCO3 在PVC基体中达到了纳米级的分散 .当纳米CaCO3 的用量为 8份 (质量 )时 ,PVC CPE 纳米CaCO3 共混物的冲击断面产生了大量的有规则的网丝状结构 ,共混物的缺口冲击强度达到 81 1kJ m2 ,比不加纳米CaCO3 的共混体系高 7 3倍 .CPE的加入对共混体系的加工流动性能无影响 ,纳米CaCO3 的加入使共混体系的加工流动性能变差

STUDY ON THE TOUGHENED PVC BLENDS WITH NANO-CaCO3 PARTICLES AND ELASTIC CPE PARTICLES

The effect of nano-CaCO 3 with mean size of 30*!nm and CPE on microstructure and properties of PVC blends was investigated.Nanoparticles of CaCO 3 were prepared in a novel rotating packed bed reactor and modified by the selected surface modifiers.Then they were mixed with polyvinyl chloride,chlorinated polyethylene and the other reagents in high-speed stirrer and the mixtures were extruded by means of single-screw extrusion.The results showed that the CaCO 3 nano particles toughen PVC/CPE blends significantly when the CPE content reached a certain value. The rigidity and the tensile strength of the blends were also increased.The notched impact strength of the PVC blend can reach 81.1*!kJ/m 2,which is 7.3 times higher than that of the blends without nano-CaCO 3.The morphology of the fracture surfaces of blends was observed by SEM.The fracture microstructure of blends implied the mechanism that the toughness of PVC/CPE was remarkably improved by the addition of CaCO 3 nano particles.And the microstructure of dispersed calcium carbonate nanoparticles in the matrix was observed by TEM.It was found that CaCO 3 nanoparticles were well-dispersed in PVC matrix at nano-scale.It is confirmed that calcium carbonate nanoparticles after properly surface-treated can be used as a new functional material.When they are well-dispersed in PVC matrix,the PVC blend is toughened remarkably.The rheological property of PVC/CPE/nano-CaCO 3 blends was also investigated.The final torque of PVC/CPE/nano-CaCO 3 blend in Brabender tests was higher than that of the blend without CaCO 3 nano particles.