超声辐照对PP/EPDM共混物在加工过程中微相结构的影响

PHASE MORPHOLOGY EVOLUTION ON PP/EPDM BLENDS IN EXTRUSION WITH ULTRASOUND IRRADIATION

研究了超声辐照对聚丙烯/三元乙丙橡胶(PP/EPDM)共混物挤出过程及二次加工中微相结构的影响。结果表明随超声功率的增加EPDM相的比表面积增大,界面作用增强。超声辐照使EPDM在PP中形成的良好的分散效果在经过热压二次成型后仍大部分得以保持。动态流变分析显示超声振动使PP/EPDM共混物的内部结构变得更加均匀。Palierne乳液模型计算结果表明,超声辐照使共混物中两相的界面张力降低,这说明超声辐照使两相间形成了良好的界面结构和牢固的界面作用,有效地阻止了EPDM液滴在共混过程以及随后的热压成型加工过程中的合并。

The effects of ultrasonic irradiation on morphology of polypropylene (PP)/ethylene-propylene-diene terpolymer (EPDM) blends during extrusion and after compression processing were examined. Results show that ultrasound irradiation lead to stable morphology with reduced disperse phase size. Dynamic mechanical analysis indicates more homogenous phase structure is obtained with ultrasound irradiation. The interfacial tension between PP and EPDM melts obtained from the palierne emulsion model decreases with ultrasound irradiation. The powerful vibration and jet current of ultrasound help to deform and shear cut EPDM in PP matrix. It also changes the viscoelasticity of the components and results in the decreasing of interfacial tension between PP and EPDM melts by ultrasound irradiation.