DESIGN OF POLYETHYLENE CABLE JACKET COMPOUNDS OF SUPERIOR JACKETING PERFORMANCE

摘要

This work demonstrates that the important jacket performance parameters (e.g., processability, shrinkage, stress crack resistance, modulus, etc.) of a polyethylene jacketing compound are dictated by the polymeric molecular architecture, molecular weight (MW) and molecular weight distribution (MWD), short-chain branching characteristics and certain morphological elements. A given structural attribute may be very valuable for certain jacket performance considerations but, at the same time, less valuable or perhaps even undesirable for others. Our ability to control and regulate, independently, the polymer MW, MWD and branching (density) and the ability to introduce other important structural entities allow for optimized combinations of the desirable polyethylene structural attributes to ensure delivery of the target jacket performance. New advanced HDPE and MDPE jacketing compounds have been developed using the UNIPOL~(TM) Process polyethylene resins to offer substantial enhancements over some traditional jacketing grades in such performance as extrudability, post-extrusion shrinkage and jacket environment stress crack resistance. (UNIPOL~(TM) Process is a trade mark of Union Carbide Corporation.)