短玻纤增强聚丙烯材料流变性能

Rheological Characteristics of Glass Fiber Reinforced Polypropylene Composite

利用双料筒毛细管流变仪,测得不同玻纤含量的短玻纤增强聚丙烯材料在不同剪切速率下不同长径比口模的压力降。对比Bagley校正法及零口模校正法得到的入口压力降之间的差别,研究玻纤含量、剪切速率对入口压力降、非牛顿指数及表观剪切黏度等流变参数的影响。结果表明:与Bagley校正法相比,零口模校正法更加可靠;短玻纤增强聚丙烯材料属于假塑性流体,存在剪切变稀行为;随玻纤含量增高,所测得的入口压力降增大,计算得到的熔体的表观剪切黏度也增大,熔体的非牛顿指数降低。

The pressure drop of short glass fiber reinforced polypropylene with varying fiber content was obtained at different shears rate by means of double-barrel capillary rheometer. The entrance pressure drops by Bagley correction and orifice correction were compared and the influences of fiber content and shear rate on the rheologic parameters of the melts such as entrance pressure drop, Non-Newtonian index and apparent shear viscosity were studied. It was found that the orifice correction compared with Bagley correction was more reliable. The short glass fiber reinforced polypropylene melt was pseudoplastic fluid which exhibits shear-thinning behavior. With the rise of glass fiber content, the measured entrance pressure droped and the calculated apparent shear viscosity increased while the Non-Newtonian index decreased.