PS/SBS/CaCO_3共混物体系脆韧转变

研究了不同组成的聚苯乙烯 (PS)基三元共混物体系的缺口冲击性能、拉伸性能和断面形貌以及相形态 .实验结果表明 ,微米级碳酸钙的增韧改性效果稍好于纳米级碳酸钙 ,但增强效果却相反 .随着分散相含量的增加 ,3种共混物韧性皆明显提高 ,拉伸曲线向右下方移动 ,应变软化减弱 ,应变硬化增强 .研究发现了随分散相含量的增加 ,PS共混物出现了脆韧转变 ,而且脆韧转变以不同的形式表现了出来 ,即冲击强度、断面形貌以及拉伸曲线在同一区间同时出现了转变

STUDIES ON THE BRITTLE-DUCTILE TRANSITION OF PS/SBS/CaCO3 SYSTEMS

The tensile behavior,noteched Izod impact strength and the morphology of the impact fracture surfaces of ternary PS blends(PS/SBS/CaCO-3) were investigated.Two kinds of CaCO-3 fillers with micrometer and nanometer sizes were used.Its was found that the CaCO-3 of micrometer sizes was a better toughness modifier than that of nanometer sizes,while the latter gave more improvement in the stiffness of the system.The toughness of the PS blends increases apparently with the increase of the SBS/CaCO-3 content.A brittle-ductile transition was observed with increasing the SBS/CaCO-3 content.All the results including the impact and tensile tests and morphological observations indicated the transition in the same content region of 31^0 wt%～37^5 wt%.