Synthetic Route Effect on Macromolecular Architecture: From Block to Gradient Copolymers Based on Acryloyl Galactose Monomer Using RAFT Polymerization

Abstract

Statistical, gradient, and block copolymer containing 2-(2′,3′,4′,6′-tetra-O-acetyl-β-d-galactosyloxy)ethyl acrylate (AcGalEA) glycomonomer and styrene (S) were synthesized by RAFT polymerization using S-methoxycarbonylphenylmethyl dodecyltrithiocarbonate (MCPDT) as control agent. The block copolymer was synthesized by a two-stage experiment, whereas the statistical and gradient copolymers were obtained in one-pot synthesis. Results obtained from the size exclusion chromatography (SEC) and the nuclear magnetic resonance (NMR) reveal that the polymers synthesized by RAFT were controlled. The kinetic of each synthetic route was investigated, and the reactivity ratio of both monomers was estimated by in situ NMR experiments: rAcGalEA = 0.07 ± 0.01 and rS = 0.7 ± 0.1. Moreover the AcGalEA moieties were deacetylated to achieve potential amphiphilic bioactive copolymer. The preparation of three different macromolecular architectures to form honeycomb porous films by breath figure process was investigated using atomic force microscopy (AFM).