摘要
采用恒速型双毛细管流变仪研究了主链型热致液晶对无规共聚聚丙烯(PPR)熔体高速挤出流变性能的影响。PPR熔体螺纹状畸变是由口模入口区的应力集中效应和横向环流造成的;利用原位成纤法制备PPR/热致液晶聚合物(TLCP)试样,TLCP在拉伸场中明显取向,随拉伸速率增大,取向程度先增大后减小;取向的TLCP明显减弱熔体挤出物的螺纹畸变现象,改善熔体在口模入口区的不稳定流动和应力集中效应,改善熔体的黏弹性;TLCP含量越多,改善效果越明显。
The authors studied the influence of main chain thermotropic liquid crystalline polymer（TLCP） on rheotogical properties of polypropylene random copolymer（PPR） through high speed extrusion by a constant speed double-capillary rheometer. The helix distortion of the PPR melt was caused by stress concentration and transverse circulation flow at the die entrance. The samples of PPR4220/TLCP were prepared with in-situ fibrillation. The TLCP phase oriented obviously in the tension field and the degree of orientation rose first and then dropped with increasing stretch rate. The oriented TLCP could significantly weaken the helix distortion of melt extrudates, alleviate unstable flow and stress concentration at the die entrance and improve the melt viscoelasticity. The higher the TLCP content, the better the improvement effect.
出处
《合成树脂及塑料》
CAS
北大核心
2011年第3期45-48,51,共5页
China Synthetic Resin and Plastics
基金
国家自然科学基金资助项目(50573037,50973050)
关键词
无规共聚聚丙烯
螺纹畸变
高速挤出
主链热致液晶聚合物
polypropylene random copolymer
helix distortion
high speed extrusion
main chain thermotropic liquid crystalline polymer
