PC/PBT合金中增韧剂粒径和增韧效果关系研究

Study on the Relationship Between Particle Size and Toughening Effect of Toughening Agents in PC/PBT Alloy

PC/PBT合金是一类综合性能优异的合金,为了满足产品要求,需要进行增韧改性,本文系统研究了该类合金中增韧剂的粒径和增韧效果的关系。研究发现MBS或者EXL增韧剂单独使用情况下,其粒径越小增韧效果越差,这和PC相与PBT相的裂纹增长能差别比较大,冲击过程中合金中裂纹发展模式是直接相关的。复配一种接枝环氧基团相容剂(X-GMA)之后,合金界面强度得到提升,裂纹发展模式发生改变,增韧剂粒径差异带来影响被减弱了,在合金体系加入X-GMA,对PBT相起到化学交联作用,会增大合金的粘度,降低PBT相的结晶温度。

The comprehensive properties of PC/PBT alloy is very excellent, in order to meet the product requirements, toughening modification is needed. In this paper, the relationship between particle size and toughening effect of toughening agents has been systematically studied. It’s found when MBS or EXL toughening agent was added separately, the smaller the particle size, the worse the toughening effect, which is related with the difference of the crack growth energy of PC and PBT phase and the crack development model in alloy during impact. After a compatibilizer grafted with epoxy group (X-GMA) was compounded, the interfacial strength of alloy was improved, the crack development model was changed, the effect of the difference in toughener particle size was weakened. X-GMA acted as a chemical crosslinking agent for PBT phase, the viscosity of alloy increased and the crystallization temperature of PBT decreased.