氨纶纺丝原液流变性能的研究

STUDY OF THE RHEOLOGICAL PROPERTY OF PU SPINNING DOPE

采用简易式毛细管流变仪、高聚物浓溶液动态粘弹仪和显微摄影技术,在模拟实际纺丝工艺条件下,测定了氨纶(PU)原液的稳态和动态流动曲线、孔口膨化比,重点研究了PU原液温度对其粘弹性的影响。研究结果证明,PU原液为切力变稀流体,结构粘度指数(Δη)、剪切弹性模量(G)均随温度升高而下降,在30—50℃范围内,Δη与G的变化甚微,这表明氨纶可在室温下纺丝,增加原液温度不仅使可纺性更佳,且有利于提高纺速,从而制得细旦氨纶。

By means of simple capillary rheometer, dynamic viscoelastometer for polymerconcentrated solution and photomicrograph techniques, the flow curves under steadystate and dynamic state of PU spinning dope, and the die swell ratio were determi-ned simulating the same conditions as actual spinning. Emphasis was given to theeffect of temperature on the rheological property of PU dope. The results show th-at the PU dope is a shear-thinning fluid and its Δ_η and G decrease with the rise oftemperature, but within the range of temperature 30--50℃,Δ_η and G change a littleonly. This indicates that PU dope can be spun at room temperature, and increasingtemperature not only improves the spinnability of the dope but also increases spinn-ing speed so as to obtain fine denier PU fiber.