Bifunctional group distribution and gradient structure resulting from the anionic copolymerization of styrene and vinylbenzyl N,N-allylmethylamine

Abstract

The synthesis of well-defined, functionalized polystyrene with a controlled molecular weight and narrow molecular weight distribution by anionic polymerization under mild conditions poses certain challenges. In this study, a novel functionalized monomer, vinylbenzyl N,N-allylmethylamine (VBAMA, ortho/meta/para = 7/23/70), carrying both tertiary amine functional groups and crosslinkable vinyl pendant groups was designed and synthesized via a substitution reaction between chloromethyl styrene (VBC) and allyl methylamine. Furthermore, a series of bifunctionalized polystyrene products were prepared through in situ anionic copolymerization with styrene with ⁿBuLi as an initiator in cyclohexane at 303 K. The kinetics of the binary copolymerization process and the comonomer sequence distribution of the copolymer were analyzed in depth. The copolymer products were comprehensively characterized by FTIR, ¹HNMR, GPC and DSC for both qualitative and quantitative analysis. The classical F–R and K–T methods were used to calculate the binary reactivity ratios (r_VBAMA = 1.54–1.59 and r_ST = 0.28–0.32), and the reactivity ratio data indicated that VBAMA has a higher anionic reactivity and tends to form a random copolymer sequence with styrene. This research provides a simple and effective synthetic route for the preparation of controllably crosslinkable, amine-difunctionalized polystyrene.