Facile access to highly functionalized polyacrylamide with ultra-high molecular weight: Multicomponent initiators-based free radical polymerization

We report a novel multicomponent initiators-based copolymerization strategy for synthesizing of acrylamide (AM) and 2-acrylamide-2-methylpropane sulfonic acid (AMPS) copolymers, denoted by P(AM-co-AMPS), with an ultra-high content of AMPS (>= 50 mol%) and an ultra-high molecular weight (>10(7)g/mol), while achieving a high conversion rate of monomer (similar to 100.0 %). The multicomponent initiators contain a redox couple, an azo compound, and a catalyst. Our investigation into the mechanism suggested that the synergistic effect in different rate constant for initiator decomposition between redox and azo initiators was responsible for actualizing ultrahigh molecular weight copolymers with high conversion rates of monomer. Moreover, copolymers with 75 mol% and 100 mol% of AMPS were synthesized to verify the advantage of the multicomponent initiators-based strategy, both of which exhibited ultra-high molecular weights and ultra-high monomer conversion rates. This study fills a long-standing gap in research on the polyacrylamide family by providing highly functionalized P (AM-co-AMPS) with an ultra-high molecular weight. Moreover, it reveals how multicomponent initiators reconcile the contradiction between the ultra-high molecular weight and the high conversion rate in copolymerization.