A continuous melt extrusion approach toward polyethylene‐based vitrimers with improved crosslinking and performance

Abstract Reported herein is a continuous one‐step melt extrusion approach for high‐density polyethylene (HDPE) vitrimers. A grafting agent and a coagent were used to produce high‐performing vitrimers. Maleic anhydride (MA) served as a reactive agent to facilitate crosslinking, while dimethyl maleate (DM) acted as a grafting enhancer by reducing the surface energy of HDPE grafted with MA. For comparison, MA alone was also tested as a grafting agent. The vitrimers obtained displayed superior mechanical properties compared with HDPE. The storage modulus, as well as crystallinity, were determined for the HDPE vitrimers. These vitrimers are reprocessable, thus supporting recycling efforts despite their crosslinked nature, owing to very fast relaxation due to low activation energy for the transesterification reaction. Consequently, these vitrimers are not only recyclable but also exhibit enhanced thermal and mechanical properties compared with conventional HDPE.