β成核剂粒径及其分布对等规聚丙烯性能的影响

摘要

采用气流粉碎机将β成核剂NT-C超细化处理得到ST-C成核剂,用激光散射技术测定了2种β成核剂的粒径及其分布.应用差示扫描量热仪(DSC)分析、偏光显微镜(PLM)观察及力学性能测试,研究了β成核剂粒径及其分布对等规聚丙烯(iPP)熔融结晶行为和力学性能的影响.结果表明:超细化成核剂ST-C的粒径更细,粒径分布更窄,ST-C的成核效果优于NT-C的.β成核剂可明显提高iPP的韧性,ST-C的增韧效果更显著,ST-C质量分数为0.025％时,缺口冲击强度是纯iPP的4.6倍.%The superfine βnucleating agent (ST-C) was prepared from NT-C using an ultrafine jet mill.The particle sizes and distribution of NT-C and ST-C were measured by laser scattering technique.The effects of particle sizes and distributions of β-nucleating agents on the melt crystallization behaviors and mechanical properties of isotactic polypropylene (iPP) were investigated by means of differential scanning calorimetry (DSC),polarized light microscopy (PLM) and mechanical tests.The results show that the particle size of ST-C is smaller and the distribution is narrower than that of NT-C.The nucleation ability of ST-C is better than that of NT-C.The toughness of iPP is greatly improved by β-nucleating agents and the improvement is more efficient by ST-C.When the mass fraction of ST-C is 0.025％,the notched impact strength is 4.6 times greater than that of the pure iPP.