张锟 吴颖莹 俞雨农 张顺花

摘 要：为探究高黏度聚酰胺6单丝的可纺性，用毛细管流变仪对高黏度聚酰胺6的剪切流变性能进行研究，分析了3种不同口模直径下熔体的剪切流变性能。结果表明：高黏度聚酰胺6熔体为切力变稀流体，其剪切黏度随剪切速率的增加而降低，随温度的升高而降低;非牛顿指数均随温度的升高而增大，随剪切速率的增加而减小;熔体的黏流活化能随剪切速率的增加而减少。口模直径直接影响熔体的流变性能，随着口模直径的增大，其非牛顿指数n值变化更为复杂;熔体剪切黏度随口模直径的增大而增大;口模直径越大，熔体黏流活化能的变化差异越大，对熔体黏度的温敏性影响越大。研究结果对高黏度聚酰胺6单丝大口模挤出生产成型的工艺条件的优化改进具有理论和实践指导意义。

关键词：聚酰胺6;口模直径;剪切流变;黏流活化能;纺丝工艺

中图分类号： TB34

文献标志码：A

文章编号：1009-265X（2021）06-0028-05

Study on Shear Rheological Properties of High-viscosity Polyamide 6

ZHANG Kun1， WU Yingying2， YU Yunong1， ZHANG Shunhua1

（1.College of Materials Science & Engineering， Zhejiang Sci-Tech University， Hangzhou 310018， China;

2.Zhejiang Jingcheng Special monofilament Co. Ltd.， Jiaxing 314000， China）

Abstract： In order to investigate the spinnability of high-viscosity polyamide 6 monofilament， the shear rheological properties of high-viscosity polyamide 6 were studied by a capillary rheometer. The shear rheological properties of melt under three different die diameters were analyzed. The results indicate that the melt of high-viscosity polyamide 6 is a shear-thinning fluid， and its shear viscosity decreases with the increase of shear rate and temperature. The non-Newtonian index increases with the increase of temperature and decreases with the increase of shear rate. The activation energy of the viscous flow of the melt decreases with the increase of shear rate. The die diameter directly influences the rheological properties of the melt. With the increase of die diameter， the change of the value of n （the non-Newtonian index） becomes more complicated. The shear viscosity of melt increases with the increase of die diameter. The larger die diameter， the greater variation in activation energy of the viscous flow of melt， and the greater influence on the thermosensitivity of the melt viscosity. The research results have theoretical and practical significance for the optimization and improvement of the extrusion and molding conditions of high-viscosity polyamide 6 monofilaments.

Key words： polyamide 6; diameter of die; shear rheology; viscous flow activation energy; spinning industry

聚酰胺是指在大分子主链重复单元结构中含有酰胺基团的一类高聚物。聚酰胺具有良好的力学性能、耐热性、耐磨损性等综合性能，在塑料、化纤等领域都有广泛的应用[1-3]，是世界上最早实现工业化生产的合成纤维，是化学纤维的主要品种之一。

聚酰胺纤维有许多种类，在中国主要为聚酰胺6和聚酰胺66，其产量约占聚酰胺總产量的90%，主要品种包含民用纤维、产业用纤维等。高黏度聚酰胺6单丝所用原料的相对黏度较高，所用喷丝板的喷丝孔径较大，其熔融纺丝工艺条件与普通纤维有显著差异，目前对聚酰胺6的流变性能研究多数停留在普通改性纤维上[4-6]，而涉及高黏度聚酰胺6的剪切流变性能研究较少。……