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以毛细管流变仪和Hakke转矩流变仪对稀土催化合成的超高分子量聚苯乙烯 (UHMWPS)的流变与加工性能进行了研究 .结果表明 ,UHMWPS最显著的流变特征为超高的熔体粘度和低剪切速率下出现不稳定流动 .不稳定流动与超高分子量聚合物长的松弛时间有关 ,并提出了临界剪切速率与分子量和温度的定量关系式 .较低的分子量和较高的温度有利于提高临界剪切速率 ,改善挤出物外观质量和降低熔体粘度 .分子链极度缠结不仅导致超高的熔体粘度 ,也使UHMWPS链解缠加快 ,导致更高的剪切速率敏感性 .UHMWPS塑化时熔体粘度高 ,转矩大 ,加工性能劣于通用聚苯乙烯 (GPPS)
The rheological and processing properties of ultra-high molecular weight polystyrene (UHMWPS) synthesized by rare earths were investigated by capillary rheometer and Hakke torque rheometer.The results showed that the most significant rheological characteristics of UHMWPS were ultra-high Melt viscosity and low shear rate instability flow instability flow and the ultra-high molecular weight polymer relaxation time, and put forward a critical shear rate and molecular weight and temperature quantitative relationship between the lower molecular weight and Higher temperatures are beneficial for increasing the critical shear rate, improving the appearance of the extrudate, and decreasing the melt viscosity. Extremely entangled molecular chains not only lead to an excessively high melt viscosity, but also unwrap UHMWPS chains, leading to higher Shear rate sensitivity.UHMWPS plastic melt viscosity, torque, processing performance inferior to general-purpose polystyrene (GPPS)