HDPE/BR/LLDPE共混体系熔体的流变特性BR含量不同的体系

Rheological Characteristics of HDPE/BR/LLDPE Blends Melt System with Different Content of BR

本文研究了 BR 含量不同的 HDPE/BR/LLDPE 共混体系熔体的流动曲线,表观粘度与温度、组成的关系,流动指数与剪切应力的关系等流变特性。结果表明,在所研究的剪切应力、剪切速率、温度及组成范围内,该共混体系熔体属于假塑性流体,表现粘度与温度的关系符合阿累尼乌斯型方程,与组成的关系不满足对数加和规律,当 BR 含量为20%和25%时,表观粘度分别出现极小位和极大值,不同温度、不同剪切应力时表观粘度与组成的关系有大体相同的规律,随着剪切应力的提高,流动指数减小;BR 在较高温度下的交联,未对该共混体系的流变行为产生明显影响。

The theological characteristics,such as the flow curve,the relationship ofη_a-T,composition and the relationship of n～τetc.have been studied on theHDPE/BR/LLDPE blends melt with different content of BR,in this paper.The results showed that the melt of blends belongs to pseudoplastic fluid withinthe range of τ,γ,T and compositions.The relationship of η_a-T fits Arrhen-ious Equation.The relationship of η_a-compositions doesn't fit the log-additi-vity rule,a maximum and a minimum of η_a appears under the conditions ofBR contents being 25% and 20%,respectively,a similar rule has been observedfor the relationship of η_a-compositions with different Τ and τ.The flow indexprogressively decreases with increase in τ.It has been observed that the the-ological behaviour of blends isn't affected obviously by crosslinking of BR athigher temperature.