PHB/PET/HQ-TPA液晶共聚芳酯流变性能研究

STUDY ON RHEOLOGICAL PROPERTIES OF LIQUID CRYSTALLINEAROMATIC COPOLYESTERS PHB/PET/HQTPA

以所合成的含５％（ｍｏｌ）第三单体（ＨＱ－ＴＰＡ）的三元液晶共聚芳酯ＰＨＢ／ＰＥＴ／ＨＱ－ＴＰＡ为原料，使用ＸＬＹ－Ⅱ型毛细管流变仪，测定了在不同温度条件下共聚芳酯样品的流变曲线。求出了不同切变速率下共聚芳酯熔体的粘流活化能ΔＥη及非牛顿指数ｎ。结果表明，ｎ＝０．２５～０．５９，ΔＥη＝６３．８２～１１６．０４ｋＪ／ｍｏｌ。实验温度范围内，共聚芳酯熔体均表现出切力变稀型非牛顿流体的特性，其剪切粘度值受温度和切变速率的影响较大。

The rheological properties of liquid crystalline aromatic copolyesters were studied by using a capillary rheometer Model XLYⅡ. The copolyesters were copolymerized by pacetoxybenzoic acid, poly(ethylene terephthalate), hydroquinone and terephthalic acid. The molar ratio of the third monomer(HQTPA) is 5%. The values of flow activation energy(ΔEη) and NonNewtonian exponent(n) of the aromatic copolyesters were calculated. The results show that n is between 0.25￣0.59 and ΔEη is in the range of 63.82￣116.04 kJ/mol. All of the copolyester melts manifest the flowing characteristic of shearshining type NonNewtonian fluid in the experimental temperature range. The values of shear viscosity were influenced mostly by temperature and shear rate.