Modulating the reactivity of polymer with pendant ester groups by methylation reaction for preparing functional polymers

Abstract

RAFT polymerization of 4-(dimethylamino)phenyl acrylate (MAPA) using 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl] pentanoic acid (CDTPA) as the chain transfer agent and AIBN as initiator yielded well-defined and narrowly distributed poly(4-(dimethylamino)phenyl acrylate) (PMAPA). As confirmed by ¹H NMR measurements, non-reactive polymer PMAPA could be converted to the reactive polymer (m-PMAPA) with a highly ionic nature by methylation reaction. The reactive m-PMAPA was quantitatively modified by various amines in DMSO, showing its practical applicability for efficient post-polymerization modifications. Furthermore, the multifunctional m-PMAPA could be directly conjugated to water-labile compounds, such as amino acids, in aqueous solutions. Additionally, using the adjustable reactivity of PMAPA, functional groups could be introduced into polymer structures in a controlled manner, yielding block copolymers with bespoke tailored functionality.