Synthesis of novel glycopolymer brushes via a combination of RAFT-mediated polymerisation and ATRP

Abstract

Glycopolymers (synthetic sugar-containing polymers) have become increasingly attractive to polymer chemists because of their role as biomimetic analogues and their potential for commercial applications. Glycopolymers of different structures confer high hydrophilicity and water solubility and can therefore be used for specialised applications, such as artificial materials for a number of biological, pharmaceutical and biomedical uses. The synthesis and characterisation of a series of novel glycopolymer brushes, namely poly(2-(2-bromoisobutyryloxy) ethyl methacrylate)-g-poly(methyl 6-O-methacryloyl-α-D-glucoside (P(BIEM)-g-P(6-O-MMAGIc)), poly(2-(2-bromoisobutyryloxy) ethyl methacrylate-co-methyl methacrylate)-g-poly(methyl 6-O-methacryloyl-α-D-glucoside) P(BIEM-co-MMA)-g-P(6-O-MMAGIc), poly(2-(2-bromoisobutyryloxy) ethyl methacrylate-b-methyl methacrylate)-g-poly(methyl 6-O-methacryloyl-α-D-glucoside) P(BIEM-b-MMA)-g-P(6-O-MMAGIc) and poly(4-vinylbenzyl chloride-alt-maleic anhydride)-g-poly(methyl 6-O-methacryloyl-α-D-glucoside) (P(S_d-alt-MAnh)-g-P(6-O-MMAGIc)) are described in this paper. Reversible addition-fragmentation chain transfer (RAFT)-mediated polymerisation was used to synthesise four well-defined atom transfer radical polymerisation (ATRP) macroinitiators (the backbone of the glycopolymer brushes). These ATRP macroinitiators were subsequently used in the 'grafting from' approach (in which side chains are grown from the backbone) to prepare high molar mass and low polydispersity index glycopolymer brushes with different grafting densities along the backbone. The number average molar mass of the glycopolymer brushes was determined using size exclusion chromatography with a multi-angle laser light scattering detector and further structural characterisation was conducted using ¹H-nuclear magnetic resonance spectroscopy. The results confirmed that glycopolymer brushes were successfully synthesised via a combination of RAFT-mediated polymerisation and ATRP.