Radical bulk functionalization of polyethylenes with ester groups

The radical functionalization of different types of polyethylene, such as high‐density (HDPE) and linear low‐density (LLDPE) polyethylene, with diethyl maleate (DEM) as a polar functional monomer and dicumyl peroxide (DCP) as radical initiator was investigated, and conditions for obtaining a controlled degree of functionalization and a low amount of degradation products without crosslinking were determined. Attention was paid to achieve a moderate functionalization of the polymer, in order to limit the modification of the mechanical and physical properties of the polyolefins. The molecular weight distribution of some of these polyethylenes was only moderately affected by the functionalization reaction. A critical discussion of the results outlines the fundamental role of process parameters such as stirring rate and heat exchange.