SHEAR AND ELONGATIONAL FLOW OF SOME BRANCHED POLYETHYLENES

The elongational properties of some branched polyethylenes are studied. Experimental results of their flow behavior are presented. The Cogswell technique of calculating the elongational viscosity together with another approach based on the work of Huang and Shroff are utilized. The results show close agreement between these two methods. Certain parameters related to material elasticity are employed. Results suggest that the elastic parameters achieve relatively high levels only if the molecular weights are sufficiently high. (C) 1994 John Wiley & Sons, Inc.