反应降解聚丙烯熔体的流变行为  

Rheological behaviors of PP melts prepared by reactive extrusion degradation

作　　者：慕晶霞[1] 张娜[1] 吴其晔[1] 

机构地区：[1]青岛科技大学高分子科学与工程学院,山东省青岛市266042

出　　处：《合成树脂及塑料》2014年第4期55-58,68,共5页China Synthetic Resin and Plastics

基　　金：国家自然科学基金资助项目(50973050;50273016;50573037)

摘　　要：采用双管毛细筒流变仪研究反应降解聚丙烯（PP）的非线性流变性能及其与分子结构参数的关系。结果表明：降解PP熔体为假塑性流体，降解程度越大，剪切黏度越低，而非牛顿流动指数增大，表明低相对分子质量PP的黏-切敏感性降低；不同相对分子质量PP试样的黏度随温度升高而下降，相对而言，低相对分子质量PP的黏-温依赖性略大，可能与分子链变短后构象熵减小有关；降解PP熔体的毛细管入口压力降（熔体弹性）随相对分子质量减小而降低；低相对分子质量PP的入口压力降~剪切速率曲线规律性差，说明降解PP熔体在毛细管入口区的流动稳定性较差。The non-linear rheological properties of polypropylene （PP） prepared by reactive extrusion degradation with different molecular structure parameters were studied by a double capillary rheometer. The results show that PP prepared by reactive extrusion degradation is pseudoplastic fluid. The shear viscosity of PP melts decreases with the degradation, but the non-Newtonian index increases, indicating the PP samples with lower relative molecular mass has low viscosity-shear sensitivity. The viscosity of the PP samples with different relative molecular mass decreases with the rise in the temperature. The viscous flow activation energy of the PP samples with lower relative molecular mass is slightly higher, which may be related to the lesser conformation entropy of shorter molecular chains. The inlet pressure drop （as characterization of melt elasticity） of the PP melts decreases with the degradation of PP, and moreover the curves of inlet pressure drop versus extrusion rate of the PP samples with lower relative molecular mass were irregular, which means that the PP melts flowing through the area of capillary entrance was unstable.

关 键 词：聚丙烯 反应降解 流变性能 分子结构参数 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]