动态保压注射成型技术对PA6/EPDM-g-MA 共混物相形态与力学性能的影响

采用动态保压注塑成型技术来控制分散相相形态和橡胶粒子在基体中的取向排列.纯尼龙,动态样与静态样具有相同的冲击强度.在加入橡胶后,动态样与静态样的冲击强度变化趋势基本一致,在橡胶含量为20%t时,体系完成脆韧转变冲击强度达到最大,在橡胶含量为30%和40%时冲击强度又下降.但与静态样相比,当橡胶含量为10%t时,动态样与静态样的冲击强度一致,而当橡胶含量超过10%时,动态样的冲击强度较静态样高.结合平行于熔体流动方向的SEM照片,在橡胶含量为10%时,动态样中的橡胶粒子与静态样一样并未被拉长与取向,而在橡胶含量超过10%时,动态样剪切层中的橡胶粒子被拉长且沿熔体流动方向取向.实验表明,在改善共混物界面相容性的基础上,适当的低剪切应力场能进一步提高橡胶分散相对冲击强度的贡献.

Effect of Dynamic Packing Injection Molding on Phase Behavior and Mechanical Properties of PA6/EPDM-g-MA Blends

In order to further study the effect of phase behavior on the mechanical properties of PA 6/EPDM-g-MA blends, dynamic injection packing molding was used to control the phase morphology and the orientation of the rubber particles in the matrix. For neat PA6, the dynamic specimens had the same impact strength as that of the static specimens. The impact strength of dynamic and static specimens had the same trend of variety with the addition of rubber. The brittle to ductile transition happened for both kinds of specimens when the rubber content was 20wt% and the impact strength decreased when the rubber content was 30wt% and 40wt%. But the impact strength of dynamic specimens was higher than that of static specimens when the rubber content exceeded 10%wt. The rubber particles were elongated and oriented along the melt flow direction in shear layer of dynamic specimens when the rubber content exceeded 10wt% while there were no elongated particles in the dynamic specimens with 10wt% rubber and in static specimens. The experiment results showed that the PA6/EPDM-g-MA blends processed via dynamic packing injection molding were tougher based on good interface adhesion.