高黏度聚酯流变行为的研究

摘要

采用毛细管流变仪研究了高黏度聚酯(PET)的表观黏度及黏流活化能随温度(280 ～ 300℃)及剪切速率(20～104 s-1)的变化.结果表明:高黏度PET熔体随着剪切速率的增加出现切力变稀现象,随着熔体温度升高,剪切速率对熔体的表观黏度的影响降低；高黏度PET的黏流活化能随着剪切速率的提高而降低；在温度为300℃,剪切速率为3000s-1时,高黏度PET熔体具有较好的流动性.%The change of the apparent viscosity and viscous flow activation energy of high-viscosity polyester (PET) with the temperature (280-300℃) and shear rate (20 - 104 s-1) was studied with a capillary rheometer. The results showed that the high-viscosity PET melt exhibited a shear thinning behavior while increasing the shear rate; the shear rate had a lower effect on the apparent viscosity of the melt while elevating the melt temperature; the viscous flow activation energy was decreased with the increase of shear rate; and the high-viscosity PET melt exhibited favorable fluidity at 300 ℃ and shear rate 3 000 s-1.