Functionalized linear low-density polyethylene by ring-opening metathesis polymerization

Functionalized linear low-density polyethylene (LLDPE) samples containing basic functional groups (cyano, primary amino-, or secondary amino-) were synthesized through the ring-opening metathesis terpolymerization of cyclooctene (COE), 5-n-hexyl-1-cyclooctene (HexCOE), and a functionalized cyclooctene (FCOE), followed by hydrogenation of the polymer backbone and deprotection of any requisite protecting group. Homopolymerization of the cyano- and tert-butoxycarbonyl (tBOC) protected amino-functionalized COEs using the Grubbs second-generation catalyst quantitatively afforded polymers having the corresponding functional groups along the polymer backbone. The terpolymerizations proceeded readily and the number of n-hexyl branches, number of functional groups, and molar mass of the polymer, could be controlled by the feed molar ratio of the monomers.