Chemoselective radical polymerization of N-allylmethacrylamide with an aid of complexation with Li+ cation

Abstract

Radical polymerization of N-allylmethacrylamide (NAlMAAm) was conducted in CH3CN in the presence or absence of lithium bis(trifluoromethanesulfonyl)imide (LiNTf2). The addition of LiNTf2 accelerated the polymerization and affected the molecular weight distribution of the polymers obtained. Polymers with unimodal molecular weight distributions were obtained in the presence of LiNTf2, whereas those with multimodal distributions were obtained in the absence of LiNTf2. This suggested that LiNTf2 suppressed side reactions such as cross-linking reaction, commonly observed in polymerization of divinyl monomers, and allylic hydrogen abstraction reaction. The 1H NMR, IR and MALDI-TOF mass analyses of the polymers obtained suggested that the radical polymerization proceeded in a chemoselective manner, leading to preferential formation of linear polymers having pendant allyl groups.