摘要
采用高级流变测试平台研究了聚碳酸酯(PC)、聚甲基丙烯酸甲酯(PMMA)和聚苯乙烯(PS)三种透明塑料熔体在低剪切速率下的流变学行为,拟合计算得到不同温度下的非牛顿指数(n)和黏流活化能。实验结果证明PC熔体在低剪切速率下n值接近1,近似于牛顿流体,PMMA和PS属于非牛顿流体,n值随温度升高而趋近1。苯环基团的存在增加了PC和PS分子链的刚性,减少了链间的无规缠绕,明显提高了熔体的流动性,而PMMA分子链的柔性特征增加了链间缠结点密度,相应降低了熔体流动性。
The rheological behavior of transparent molten plastics, including polycarbonate （PC）, polyrnethylmethacrylate （PMMA）and polystyrene （PS）, were studied under the low shear rate by advanced rheological testing platform.The non-Newtonian index （n）and viscous flow activation energy under variable temperature were fitted numerically.The experimental results verify the n value of PC melt under the low shear rate is close to 1, which is approximately Newtonian fluid.PMMA and PS could be treated as Non-Newtonian fluids and their n values approach to 1 with temperature increasing.The exist of benzene in main chains of PC and PS promote the rigidity of molecule and reduce the random entanglement between the segments and chains, which improve the flowability of melts obviously.However, flexibility of PMMA molecules increase node density of entangled molecules and decrease the flowability of melts.
出处
《工程塑料应用》
CAS
CSCD
北大核心
2013年第4期71-74,共4页
Engineering Plastics Application
关键词
透明塑料熔体
低剪切速率
黏流活化能
无规缠结
transparent molten plastics
low shear rate
viscous flow activation energy
random entanglement
