mLLDPE／LDPE共混物的流变性能  

Study on the rheological property of mLLDPE/LDPE blends

作　　者：刘祥贵[1] 陆霞[1] 王占杰[1] 赵贝[1] 吴其晔[1] 

机构地区：[1]青岛科技大学,教育部橡塑工程重点实验室,山东青岛266042

出　　处：《合成树脂及塑料》2009年第6期50-53,65,共5页China Synthetic Resin and Plastics

基　　金：国家自然科学基金资助项目(50273016,50390090,50573037)

摘　　要：采用恒速双毛细管流变仪研究了茂金属线型低密度聚乙烯(mLLDPE)与低密度聚乙烯(LDPE)共混物的高速挤出流变行为。混入LDPE[w(LDPE)为10%～30%]后,共混物黏度比纯mLLDPE低,挤出胀大比和入口压力降比纯mLLDPE高;mLLDPE高速挤出时的压力振荡现象得以改善,熔体在毛细管内壁的应力集中效应减弱;共混不能改善mLLDPE的挤出畸变,与纯料相比,共混物的各种挤出畸变(包括鲨鱼皮畸变、黏-滑畸变、熔体破裂)加重,第二光滑挤出区消失。mLLDPE与LDPE共混相容性较好,共混物熔点位于2种纯料之间。The rheological behavior of the metallocene-catalyzed linear low density polyethylene（mLLDPE） and low density polyethylene（LDPE） blends extruded at high speed were studied through a double-capillary rheometer working at constant speed. The results show that the viscosity of the blends is lower than that of pure mLLDPE, whle extrusion swelling ratio and entrance pressure drop are higher with LDPE mass content of 10%- 30%. The pressure oscillation of mLLDPE extruded at high speed as well as stress concentration effect of the melt on the inner wall of the capillary decrease. Compared with pure mLLDPE, extrudate distortion of the blends including shark skin, stick-slip and gross melt fracture are exacerbated, and the second smooth extrusion section disappears. The blends have good compatibility and the melting points of the blends are between those of mLLDPE and LDPE.

关 键 词：茂金属线型低密度聚乙烯 低密度聚乙烯 共混 流变 不稳定流动 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业]