尼龙612及其共聚物流变性能的研究

采用毛细管流变仪对尼龙612/6(PA612/6)共聚物的流变性能进行了研究,并与PA612进行比较。结果表明:PA612/6共聚物和PA612熔体均为剪切变稀的假塑性非牛顿流体,在相同温度和剪切速率下,PA612/6共聚物熔体的表观黏度均小于PA612的;在温度为240℃时其非牛顿指数分别为0.749,0.748;随着温度的升高,两者熔体的表观黏度和稠度系数均逐渐下降,非牛顿指数逐渐增大;PA612/6共聚物和PA612熔体的黏流活化能随剪切速率的增大先增大后减小,在剪切速率为115s-1左右时,两者的黏流活化能达到最大,分别为61.49,61.27kJ/mol,此时熔体的表观黏度对温度的敏感性最强。

Rheological behavior of nylon 612 and its copolymer

The rheological behavior of nylon 612/6(PA 612/6)copolymer was studied with a capillary rheometer and was compared with that of PA 612.The results showed that PA 612/6 copolymer and PA 612 melts were shear thinning pseudoplastic non-Newtonian fluids,and the apparent viscosity of PA 612/6 copolymer melt was less than that of PA 612 at the same temperature and shear rate;the non-Newtonian indices were 0.749 and 0.748 at 240℃,respectively;the apparent viscosity and consistency coefficient of the melts decreased gradually and the non-Newtonian indices increased gradually with the increase of temperature;the viscous flow activation energies of PA 612/6 copolymer and PA 612 melts first increased and then decreased with the increase of shear rate and reached the maximum of 61.49 and 61.27 kJ/mol,respectively,and the apparent viscosity of the melts was most sensitive to temperature when the shear rate was about 115 s-1.