低剪切速率下不同特性黏数PBT切片的流变性能研究  

Rheological properties of PBT chip with different intrinsic viscosity at low shear rate

作　　者：张建 李晶 孟楷 ZHANG Jian;LI Jing;MENG Kai(Research Institute of SINOPEC Yizheng Chemical Fibre Co.,Ltd.,Yizheng 211900)

机构地区：[1]中国石化仪征化纤有限责任公司研究院,江苏仪征211900

出　　处：《合成纤维工业》2023年第1期39-42,共4页China Synthetic Fiber Industry

摘　　要：采用旋转流变仪测试不同特性黏数(0.73~1.20 dL/g)的聚对苯二甲酸丁二醇酯(PBT)切片在低剪切速率(γ)下的流变性能,并研究其非牛顿指数(n)和黏流活化能(Eη)随γ的变化规律。结果表明:在低γ下,不同特性黏数的PBT熔体均存在明显的第一牛顿区(γ小于10 s^(-1))和假塑区(γ为10~100 s^(-1)),剪切黏度(η)随γ和温度的增加而降低;随特性黏数的增加,PBT熔体的n在第一牛顿区变化较小(变化值小于0.03),在假塑区逐渐减小;在γ小于10 s^(-1)时,PBT熔体的Eη也存在明显的平台区,E_(η)变化值小于10 kJ/mol;γ大于10 s^(-1)时,随着γ的增大,PBT熔体的E_(η)逐渐减小;在相同γ下,随着PBT特性黏数的增加,PBT熔体的Eη逐渐减小,特性黏数为0.73 dL/g的PBT的温度敏感性最高,特性黏数为1.20 dL/g的PBT的温度敏感性最低,γ敏感性最高。The rheological properties of polybutylene terephthalate (PBT) chips with different intrinsic viscosity (0. 73-1. 20d L/g) were measured with rotating rheometer at low shear rate (γ). The change law of non-Newtonian index (n) and viscous flow activation energy (E_(η)) of PBT chip with γ was studied. The results showed that PBT melts with different intrinsic viscosity all had obvious first Newtonian zone (γ lower than 10 s^(-1)) and pseudoplastic zone (γ of 10-100 s^(-1)),and the shear viscosity (η) was decreased along with the increase of γ and temperature at low γ;n of PBT melt changed slightly in the first Newtonian zone (the variation less than 0. 03) and gradually decreased in the pseudoplastic zone with the increase of intrinsic viscosity;there was also an obvious platform area of Eη,i.e. the variation less than 10 k J/mol,at γ lower than 10 s^(-1);E_(η) of PBT melt gradually decreased with the increase of γ above 10 s^(-1);and Eηof PBT melt gradually decreased with the increase of intrinsic viscosity of PBT at the same γ,and PBT with an intrinsic viscosity of 0.73 d L/g had the highest sensitivity to temperature while PBT with an intrinsic viscosity of 1.20 d L/g had the lowest sensitivity to temperature and the highest sensitivity to γ.

关 键 词：聚对苯二甲酸丁二酯纤维 特性黏数 剪切速率 流变性能 

分 类 号：TQ342.22[化学工程—化纤工业]