Minority structures are considered to be defect structures that are formed during polyethylene (PE) preparation and during the crosslinking process in PE. The minority structures that play the predominant role in PE crosslinking are vinyl double bonds. Moreover, the decomposition of dicumyl peroxide in PE does not proceed according to first-order kinetics, but induced peroxide decomposition also takes part. (C) 2003 Wiley Periodicals, Inc.