Precision Synthesis of Narrow Polydispersity, Ultrahigh Molecular Weight Linear Aromatic Polymers by A2 + B2 Nonstoichiometric Step-Selective Polymerization

A reliable and practical approach is offered for the two critical fundamental challenges that remain in step-growth polymerization: synthesis of narrow polydispersity and ultrahigh molecular weight polymers. The polymers are obtained by superacid catalyzed polyhydroxyalkylation involving two consecutive steps - slow and fast. Polymer syntheses with decrease in reactivity of intermediates lead to narrow polydispersity polymers, while nonstoichiometric reactions result in polymers of high and ultrahigh molecular weight. Linear aromatic polymers with ultra high molecular weight M-n > 1 000 000 and narrow polydispersity (M-w/M-n = 1.15-1.16) have been obtained. An unusual step-selective mechanism is suggested for the formation of these polymers.