Synthesis of Copolymers of Methacrylate Bearing Five-Membered Cyclic Carbonate Pendant Group with 2-Hydroxyethyl Methacrylate, Their Solubility, Their Thermal Properties, and Application to Networked Polymer Synthesis

Abstract

Free radical copolymerization of glycidyl methacrylate (GMA) and 2-hydroxyethyl methacrylate (HEMA) was conducted in tetrahydrofuran (THF) using 2,2’-azobisisobutyronitrile (AIBN) as a radical initiator. The copolymerization proceeded smoothly to give the corresponding copolymers (P(GMA-HEMA)) in high yields. The compositions of the resulting copolymers were almost the same as the monomer feed ratios. The epoxy group of the copolymers was converted efficiently to five-membered cyclic carbonate group by CO2 incorporation reaction using dicyclohexylammonium iodide (DCAI) to give copolymers bearing cyclic carbonate pendant group (P(MA5CC-HEMA)). The copolymers consisting of equimolar amounts of MA5CC and HEMA units were crosslinked with hexamethylenediamine (HMDA) or 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) to form networked polymers by ring-opening hydroxyurethane formation reaction. In addition, the copolymer was cross-linked with hexamethylene diisocyanate (HMDI) by tin-catalyzed addition reaction of the hydroxy group of HEMA unit to afford network polymer.