Physical properties of extended‐chain high‐density polyethylene

摘要

AbstractExtended‐chain high‐density polyethylene prepared through crystallization at high pressure is substantially stiffer and somewhat stronger than normal folded‐chain HDPE. With weight‐average molecular weight in the range normal for molding or extrusion resins, the extended‐chain material is inductile and brittle; but with molecular weight near 2,000,000, the resin can be rigid and tough. This rigid, tough material can be converted to articles through some of the solid‐state processes developed for metals. The volume–temperature behavior of HDPE at 5000 atmospheres appears to reflect a polymorphic transition between orthorhombic and tri