聚合填充法制备UHMWPE/Kaolin复合材料的强流变行为及机理

线性聚乙烯熔体的强异常流动行为源于其高分子量，分子链缠结点多，熔体的界面吸附性强。界面吸附作用的极度变化是造成异常流动的外因，而口模壁附近吸附链和未吸附链间的缠结-解缠结动力学振荡，则是导致挤出压力振荡的内因。用聚合填充法制备的UHMWPE/Kaolin和HDPE／Kaolin体系可以顺利地由毛细管挤出，且填充量增大，体系表现粘度下降，加工流动性变好。在滑动动力学边界条件下，熔体在管壁附近所承受的真实剪切速率和剪应力减少。管壁处粘性作用的下降（脱附）和物料实际承受的弹性变形能减少，是第二光滑区中获得稳定滑动流动的重要条件。

Extreme Rheological Behaviors of Linear PE and PE/Kaolin Composite

The extreme flow behaviors of linear PE melts are caused by the high molecularweight, more entanglements and strong adsorption of melt at the capillary wall. The extremechange of interface adsorption is the external cause of special flow, and the dynamic vibration ofentanglement and disentanglement between adsorption chain and non-adsorption chain near thewall is the internal cause of the extrusion pressure vibration. UHMWPE/Kaolin and HDPE/Kaolin prepared by polymerezation - filling can be smoothly extruded through capillary, and withincreasing addition of Kaolin the apparent viscosity of the composite is decreased and theprocessability is improved. Under slip border condition the real shear rate and shear stress of themelts near the wall are decreased. The viscosity descent and the deformation energy decrease ofthe melt near the wall are the important conditions to gain steady flow in the second glossy zone.