Environmental stress cracking resistance of polyethylene: The use of CRYSTAF and SEC to establish structure-property relationships

Nineteen commercial high-density polyethylene resins made with different po lymerization processes and catalyst types were analyzed by high-temperature size exclusion chromatography and crystallization analysis fractionation. The information obtained with these characterization techniques on the poly mer chain structure was correlated to environmental stress cracking resista nce. Environmental stress cracking resistance increases when the molecular weight and concentration of polymer chains that crystallize in trichloroben zene between 75 and 85 degrees C increase. Polymer chains present in this c rystallization range are assumed to act as tie molecules between crystal la mellae. (C) 2000 John Wiley & Sons, Inc.