线型聚乙烯及其共聚物的挤出畸变与熔体粘弹性的关系  

The Extrudate Distortion and the Non-linear Viscoelasticity of Linear PE and its Copolymer Melts

作　　者：吴其晔[1] 巫静安[1] 温学明[1] 王新[1] 李鹏[1] 王淑英[1] 

机构地区：[1]青岛科技大学,青岛266042

出　　处：《高分子通报》2005年第1期66-72,100,共8页Polymer Bulletin

基　　金：国家自然科学基金 (5 0 2 730 16 )

摘　　要：采用恒速型双筒毛细管流变仪研究了一类线型聚乙烯熔体的挤出畸变与熔体非线性粘弹性的关系。实验研究了发生畸变时挤出压力的振荡规律 ,发现线型大分子或带小侧基的大分子熔体 ,容易发生壁滑和挤出压力振荡 ;而有较大侧基、或分子量分布宽、或带大量短支链的熔体 ,挤出畸变现象较轻。挤出畸变与熔体的弹性及熔体 壁面吸附状态紧密相关。容易发生壁滑和挤出压力振荡的熔体 ,弹性较大 (入口压力降大 ) ;在壁面的吸附作用强 (壁面临界剪切应力大 )。稳态剪切粘度大小与挤出畸变和压力振荡的关系不大 ;而拉伸应力和拉伸粘度大的熔体较易发生壁滑和挤出压力振荡。The relationships of extrudate distortion and the non-linear viscoelas ticity for HDPE, POE, EPDM etc were studied by capillary rheometer. It is indica ted that the melt slip at wall and the extrusion pressure oscillation were easy o ccurred in linear macromolecule melts and difficulter occurred in polymer melts having biger side-group or broader molecule weight distribution, or having a lo t of short side-chain. More the chain entanglement, and more the shear stress be twe en melts and the wall of capillary, the melt slip at wall and the pressure oscil lation became stronger. The melts fracture behaviors were influenced more by the extensional viscosity, but less by the steady shear viscosity of melt.

关 键 词：熔体 挤出压力 聚乙烯 拉伸粘度 毛细管流变仪 线型 共聚物 侧基 非线性粘弹性 壁面 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业]