PVC通信电缆绝缘料流变行为的研究

本文采用毛细管流变仪对聚氯乙烯电缆料的加工流变性能进行了研究，分析并讨论了影响ＰＶＣ流变性能的各种因素。结果表明：在试验温度下，增塑ＰＶＣ的剪切应力均随剪切速率的增加而增大，但当剪切速率增加到一定程度后，剪切速率对剪切应力的影响变小；改性剂ＰＭ－１的加入可以大大降低在相同剪切速率下的剪切应力。改性剂ＰＭ－１使电缆料的剪切敏感性减小，牛顿性增强。虽然ＰＭ－１不能改变临界剪切应力值，但却使当临界剪切应力相应的熔体粘度减小，即临界剪切速率增大，这在实际生产过程中是十分有用的，即可以提高挤出速度而不致于产生熔体破裂。分子量减小，熔体表观粘度明显减小。熔体表观粘度随温度的升高而逐渐减小。

On the Rheological Behaviour of PVC Compound for Insulating Jacket of Cable

The rheological behaviour of PVC compound for insulating jacket of cable was studied by means of capillary rheometer,and factors having effect on the rheological behaviour were also analyzed and discussed in this paper.The results showed at test temperature the shear stress of the plasticized PVC increased with the increase of the shear rate of PVC, but when the shear rate increased to a certain level,the effect of the shear rate on the shear stress became small;when the shear rate was unchanged,the shear stress could be greatly reduced by the use of modifier PM 1.The modifier could reduce the shear sensitivity and improve the Newtonian behaviour of the compound.Although the modifier had no effect on the critical shear stress,but could reduce the melt viscosity related to the critical shear stress,which meant an increase to the critical shear rate and an increase to extrusion rate without melt fracture,being valuable in production practice.When molecular weight decreased,the melt apparent viscosity decreased obviously,and the melt apparent viscosity also decreased with the increase of temperature.