云母/聚丙烯共混物熔体的拉伸流变性能

Extensional rheological behavior of Mica/PP blend melt

采用双料筒毛细管流变仪和Haul-off牵伸设备,研究了云母(Mica)/聚丙烯(PP)共混物在拉伸流场中的流变性能。结果表明:Mica/PP共混物熔体拉伸流动属于拉伸变稀型,随着云母含量的增加,熔体的表观拉伸黏度逐渐增大。熔体的拉伸应力和表观拉伸黏度均随温度的升高而下降。随着拉伸应变速率的提高,熔体的拉伸应力增大,表观拉伸黏度减小,熔体拉伸流动活化能呈下降趋势。云母微粒的加入使聚丙烯熔体的拉伸模量明显增大,但随着拉伸速度的提高,共混熔体的拉伸模量下降显著。为了提高Mica/PP共混物的纺丝稳定性,应严格控制好拉伸速度和加工温度。

The rheological behavior in extensional flow of the melt of mica/polypropylene（PP） blend was researched by twin-bore capillary rheometer and Haul-off equipment.The results show that rheological property of all the Mica/PP samples appear extensional thinning behavior,with the increase of the mica content,the apparent extensional viscosity increases.The extensional stress and the apparent extensional viscosity decline with the rise of temperature.The extensional stress increases,the apparent extensional viscosity and the activation energy of extensional flow viscosity decrease with increasing the extensional strain rate.The added mica particles make the tensile modulus of PP melt increase remarkably,but with the increase of drawing speed,the tensile modulus of the blend melt decreases significantly.In order to improve the spinning stability of Mica/PP blend,it was important to control the drawing speed and processing temperature.