Nonisocyanate Poly(hydroxyurethane)-Based Graft Copolymers with Enhanced Mechanical Properties
발표자
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초록
내용
Production of nonisocyanate poly(hydroxyurethane) (NIPU) via aminolysis of cyclic carbonate not only consumes CO2 but also eliminates the need for toxic isocyanate compounds. However, NIPUs prepared from aliphatic cyclic carbonates show low glass transition temperature (Tg), thus low modulus at room temperature and limited commercial utility. To address this issue, we employ a copolymerization strategy to prepare graft copolymers with NIPU backbone and high Tg poly(methyl methacrylate) (PMMA) side chains. The hydroxyl groups in NIPU are modified to alkyl halide as initiators for atom transfer radical polymerization (ATRP). We demonstrate control of grafting density by varying the substitution level of the hydroxyl group as well as control the length of the side chain by varying the monomer-to-initiator ratio. The successful synthesis of PMMA-grafted NIPU copolymers is confirmed, and thermal characterization shows that the Tg is closely correlated with its side chain density and chain length.