PET/PA66共混体系的流变性质与形态结构的关系

THE RELATION BETWEEN RHEOLOGICAL PROPERTIES AND MORPHOLOGICAL STRUCTURE IN THE BLENDED PET,/PA66 SYSTEM

采用溶液法、熔融法Ⅰ(简单机械共混)和熔融法Ⅱ(存在酯—酰胺交换反应)共混,将聚对苯二甲酸乙二酯(PET)与聚酰胺66(PA66)共混。用Instron 3211型毛细管流变仪和扫描电镜研究了共混体的流变性能和形态结构.结果表明,PET/PA66共混体熔体为切力变稀流体,其行为遵守幂律方程,η(?)C_(pass)(wt.％)曲线表明该共混体为一负偏差体系,当PA66含量为25％左右时,负偏差最大。不同共混方式所制得的共混物形态结构的差异是造成共混物流变性能差异的直接原因。

Abstract The blends of polyethylene terephthalate (PET) with Polyamide-66 (PA66) are prepared by three different methods) Solution, Melting with simply Mechanical mixing ( I ). and Welting with ester-amide exchaging reaction ( I ). The rheological properties and morphological structure of the blends obtained ate determined by a capillometer of type Instron 3211 and SEM, respectively, The results show that the blended PET/PA66 melts are shear-thinning fluids and obey the power rule in the temperature range tested. The vis- cosity-composition curves measured indicate that the blended system is of negative devia- tions, and the maximum deviation appears at about 25/owt of PA66. The reason for the rheological property difference between the blends prepared with different methods lies in the difference of their morphological structures.