聚丙烯/尼龙6共混物熔体的松弛时间

Relaxation Time of Polypropylene/Polyamide 6 Blend Melts

用扫描电镜对聚丙烯(PP)/尼龙6(PA6)共混物断面形貌进行了表征,用旋转流变仪小振幅剪切模式测试了PP/PA6共混物的动态模量,并采用广义Maxwell模型对于损耗模量-角频率曲线进行了拟合。扫描电镜结果表明,聚丙烯接枝马来酸酐(PP-g-MAH)有效提高了PP和PA6之间的相容性,使得分散相PA6粒径尺寸减小。广义Maxwell模型中,当松弛模数为N=5和6时,拟合曲线与实验数据在低频下存在明显的偏差,而松弛模数为N=7时,广义Maxwell模型能够较好地拟合实验曲线。固定PP/PP-g-MAH质量比为90/6时,随着PA6含量的增加,共混物PP/PP-g-MAH/PA6的松弛时间延长,松弛时间谱曲线以短时区为轴心逆时针旋转,向长时区偏移。

The structure morphology of cross-section characterized by scanning electron microscope （SEM）. of the polypropylene/polyamide 6 （PP/PA6） blends was The dynamic modulus was measured by small amplitude oscillatory shear on rotationary rheometer, and the loss modulus-angular frequency data was fitted by the generalized Maxwell model. The SEM results show that polypropylene grafted maleic anhydride（PP-g-MAH）improves the compatibility between PP and PA6 phase. When the relaxation modulus N of the generalized Maxwell model is 5 or 6, obvious deviation exists between the fitted curve and the experimental loss moduli data at low angular frequency, but when N increases to 7, the model can fit the data well. When the weight content of PA6 phase increases with the fixed mass ratio PP/PP-g-MAH of 90/6, the relaxation time of the PP/PP-g-MAH/PA6 blends increases, the relaxation modulus-relaxation time curve rotates anticlockwisely to long time zone along the axis of short time zone.