聚碳酸酯/1,2-丙二醇改性共聚酯合金的流变性能研究

摘要

以聚碳酸酯(PC)和自制的1,2-丙二醇改性共聚酯(PPET)为原料,通过熔融共混的方法,制备了PC/PPET合金,通过毛细管挤出流变仪研究了其流变行为.结果表明,在240～255℃的范围内,PC的流动性低,无法进行流变实验,而PC/PPET合金具有较好的流动性,即PPET的加入使体系中PC的加工性能变好,可以在较低温度下加工;在此温度范围内,PC/PPET合金为假塑性流体;相同的切变速率下,PC/PPET合金的黏流活化能随着PPET含量的增加呈先减小后增大的趋势,当PC/PPET的质量比为4/1和1/4时,合金熔体的黏-温依赖性较大,更适合使用升高温度的方法来改善其流动性.%Polycarbonate (PC) and self-made copolyester (PPET) modified by 1,2-propylene glycol were used as raw materials to prepare PC/PPET alloys by melt blending,and their rheological behaviors were studied by a capillary extrusion rheometer.The results indicated that the rheological experiment could not be implemented in the temperature of 240～255 ℃ due to the poor fluidity of PC.However,the PC/PPET alloys exhibited a good flowing property,indicating that the addition of PPET improved the fluidity of PC and thus made it processable at lower temperatures.The PC/PPET alloys present a pseudoplastic fluid in the above temperature range,and a decrease in viscous-flow activation energy in the beginning and then tended to increase with increasing PPET content.When the mass ratio of PC/PPET was set to 4/1 and 1/4,the temperature dependency of viscosity was more significant for the alloys,and the elevation of temperature was a suitable means to enhance the fluidity of the alloys.