丁醛等离子体处理填料对填充聚烯烃熔体流变性的影响

RHEOLOGY OF POLYOLEFINE MELTS FILLED WITH BUTYL ALDEHYDE PLASMA-TREATED MICA

用毛细管流变仪研究了经丁醛等离子体处理的云母粉填充高密度聚乙烯熔体(160℃)和聚丙烯熔体(180℃)的流变性。数据表明,处理削弱了非填充聚烯烃熔体流动的非牛顿性,熔体流动的牛顿指数随等离子体处理时间的延长而增大。处理降低了填充聚烯烃熔体在低切变速率下的表观粘度,提高了其在高切变速率下的表现粘度,发生转变的临界切变速率对填充聚乙烯和聚丙烯分别为150s^(-1)和50s^(-1)。扫描电镜观察熔体形态证实,处理对熔体粘度的复杂影响,是处理改善填料在熔体中的分散性和提高填料与基体界面结合力两者综合作用的结果。

The rheological properties and morphology of high density polyethylene and polypropylene melts filled with mica which had been treated by radio frequency plasma oi butyl aldehyde were studied by using a capillary rheometer and a scanning electron microscope. Shear rate ranged from 1 to 103s-1.Rabinowitsch method was applied to all the rheometric data for non-Newtonian correction.The results showed that the non-Newtonian index of the filled melts increases with the plasma treating time, that is, the plasma treatment weakens the non-Newtonian characteristics of the melt flow.Also, the shear viscosity of the filled melts is decreased by the plasma treatment in case of shear rate lower than 150s-1 for the filled polyethylene and than about 50s-1 for the filled polypropylene.At higher shear rates, the opposite was observed.This complex influence upon the melt viscosity was considered to be result of the competition between antiflocculating fillers and strengthening filler/matrix interface both by the plasma treatment,This was verified by examining the morphology of the capillary extrudates.