碳酸钙填充聚丙烯振动剪切行为的流变模型

Rheological Model for CaCO_3/PP Composite Melts under Oscillatory Shear

用修正的粘弹宾汉流体模型描述了碳酸钙填充聚丙烯复合材料在融熔状态下的大振幅剪切振动流变行为 .验证了在剪切应力低于屈服应力时 ,变形基本上是弹性的 ,而屈服后粘流过程显示了触变特性 .在大振幅振动下 ,除应变幅度和频率外 ,填充比和表面状况是决定流变行为非线性程度的重要因素 .碳酸钙体积填充含量达到 1 2 %时 ,屈服使应力响应是准周期的 ;当达到 2 5%或30 %时 ,屈服和触变很明显 ,非线性的应力波形变为衰减的梯形 .

A visoelastic Bingham fluid model was proposed for CaCO 3/PP composite in melt state under oscillatory shear quantitatively well. Elastic deformation occurs at stress below the yield stress, the viscous flow appears after yield with thixotropy. The advantage is that it considers structure correlation and time dependence for highly filled systems, which exhibits in two aspects: the first is that the behavior, at the starting stage, changes with filling ratio and surface treatment. Furthermore, it is possible that the stress period is shortening. The second is that the viscosity is attenuated after yield: the higher is the filling ratio, the reduction of viscosity is more dramatic; surface treatment renders the degree of such attenuation to be smaller.