Polymer-to-polymer chemical transformations to produce specialty plastics from waste polyolefins

Recent advances in the dehydrogenation of polyolefins are opening new opportunities for polymer-to-polymer chemical transformations of waste plastics. Functionalizing the C=C bonds provides viable routes for incorporating associating groups that enhance mechanical, adhesive, and transport properties. For two specific associating groups, we demonstrate this approach by functionalizing, polycyclooctene with (1) hydroxyl groups to mimic poly(ethylene-co-vinyl alcohol) copolymers or (2) carboxylic acid groups to mimic poly(ethylene-co-acrylic acid) copolymers. The level of functionalization controls the glass transition temperature, melting temperature, percent crystallinity, and surface properties, as generally observed in comparable polymers synthesized from petroleum feedstocks. In addition, electrochemical impedance spectroscopy studies reveal multiple subsegmental relaxations in these associating polymers. This discovery enables us to directly measure the intrinsic relaxation time and activation energy of the sticker association/dissociation process. These studies with the model substrate polycyclooctene demonstrate the viability of combining dehydrogenation and functionalization of polyethylene’s to produce specialty plastics from waste polyolefins.