UHMWPVC/LMWPVC共混增塑体系流变行为的研究

STUDY ON RHEOLOGICAL PROPERTY OF UHMWPVC LMWPVC BLENDED AND PLASTICIZED SYSTEM

采用机械方法将ＴＨ－４００型ＬＭＷＰＶＣ与Ｐ－２５００型ＵＨＭＷＰＶＣ共混增塑，并对共混增塑体系的流变性能进行了系统的研究。结果表明，该体系为典型的假塑性流体，其非牛顿指数ｎ随着剪切速率的增大而减小，随着温度的升高而增大。ＬＭＷＰＶＣ的加入，有效地降低了共混体系的粘度。当剪切速率大于２４３ｓ－１后，体系的粘流活化能明显降低，试样的ＳＥＭ照片表明，随着剪切速率的增大，熔体中的初级粒子尺寸减小。该体系可用作聚氯乙烯热塑性弹性体（ＰＶＣ－ＴＰＥ）。

n order to improve rheological and processing properties of UHMWPVC resin, TH400 LMWPVC and P2500 UHMWPVC were blended and plasticized with mechanical method, and rheological property of blended system was studied. The results showed that the system is a typical pseudoplastic fluid. Its nonNewtonian index n decreases with the increment of shear rate and increases with the increment of temperature. The addition of LMWPVC led to effective reduction of the viscosity of the blended system. The activation energy of the system decreases remarkably when shear rate is larger than 243 s-1. SEM pictures of specimen indicated that the greater the shear rate was, the smaller the size of primary particle of melted resin was. The system is applied to thermoplastic elastomer(PVCTPE).