压力流场中含炭黑聚对苯二甲酸乙二醇酯熔体的流变特性

Rheological Properties of Polyethylene Terephthalate Melt Containing Carbon Black in Pressure-driven Flow

利用毛细管流变仪及反向压力腔组件研究了压力流场中含炭黑聚对苯二甲酸乙二醇酯(PET)熔体的流变行为,并与普通PET熔体的流变行为进行对比。结果表明:随剪切速率的增加,含炭黑PET熔体的“剪切变稀”行为比普通PET更显著;在相同温度和相同剪切速率下,含炭黑PET的剪切黏度随着压力的增加而增加;在相同剪切速率和相同压力下,随着温度的升高,含炭黑PET熔体的剪切黏度逐渐减小;压力增加ΔP与温度下降ΔT对剪切黏度的贡献是等效的;在相同剪切速率下,含炭黑PET熔体的黏-温依赖性随压力的升高而增强;在相同压力下,含炭黑PET熔体的黏-温依赖性随剪切速率的增加而减弱;随着温度的升高,普通PET和含炭黑PET熔体的结构粘度(Δη)降低,可纺性提高;当温度为290~295℃时,普通PET和含炭黑PET熔体的可纺性最优。

Rheological behavior of carbon black polyethylene terephthalate(PET)melt in pressure flow field was studied by capillary rheometer and reverse pressure chamber assembly,and was compared with that of ordinary PET.The results showed that with the increase of shear rate,the shear thinning behavior of carbon black-containing PET melt was more significant than that of ordinary PET.At the same temperature and shear rate,the shear viscosity of carbon black PET increased with the increase of pressure;at the same shear rate and pressure,the shear viscosity of carbon black PET melt decreased with the increase of temperature.The contribution of pressure increasing and temperature decreasing to shear viscosity was equivalent.At the same shear rate,the viscosity-temperature dependence of carbon black PET melt increased with the increase of pressure;at the same pressure,the viscosity-temperature dependence of carbon black PET melt decreased with the increase of shear rate.With the increase of temperature,theΔηof ordinary PET and carbon black-containing PET melt was reduced,and the spinnability was improved.When the temperature was between 290℃ and 295℃,the spinnability of ordinary PET and carbon black-containing PET melt was optimal.