Study on Crosslinking of Polyethylene–Octene Elastomer with Dicumyl Peroxide

Abstract

A crosslinkable metallocene polyethylene–octene elastomer (POE) containing different amounts of dicumyl peroxide (DCP) was prepared in a mixer at 110°C to remove the methanol and to ensure a uniform distribution of DCP. A crosslinking reaction of the crosslinkable mixture was carried out for 20 min in a hot press at 140°C. The properties of crosslinked products have been examined in the present study. From the results of 13C NMR, it was found that H-Link was produced on the molecular structure of POE resulting from the crosslinking reaction with DCP. The molecular weight (MW) between crosslinks of the gel was determined from Flory-Rhener theory and the result showed that MW decreased as DCP concentration was increased. According to the result of DSC and x-ray diffraction characterizations, it was found that the crystalline structure of POE was altered after crosslinking and the degree of crystallization decreased with increasing DCP content. Tensile and tear tests showed that the magnitudes of tensile strength and elongation at break, fracture energy, threshold fracture energy, and effective unstrained diameter of the tear tip all decreased when the DCP loading was increased.