Anomalous rheological behavior of polyethylene melts in the gross melt fracture reeime in the capillary extrusion: Effect of long-chain branching

作者：Lee Hwi Yong; Kim Dong Hak; Son Younggon^*

来源：Journal of Applied Polymer Science, 2008, 107(4): 2350-2355.

DOI：10.1002/app.27382

• gross melt fracture
• sharkskin
• polyethylene extrusion
• abnormal rheological behavior
• metallocene polyethylene
• long-chain branching

During a capillary extrusion with several different polyethylenes, we observe an abnormal rheological behavior. The nominal viscosity of some polyethylene melt in the gross melt fracture regime does not change with the temperature. Several metallocene-catalyzed linear low density polyethylene are investigated. Among them, polyethylenes, which have long-chain branches in their main chain, show this abnormal rheological behavior. By capillary extrusion experiments with various dies of different L/D ratios, it is inferred that the abnormal rheological behavior is originated in the die land, not die entrance nor die exit. From various experiments, we notice that this abnormal phenomenon may be used to detect long-chain branch of PE.

• 出版日期2008-2-15