Multiresponsive triblock copolymers based on poly(oligo(ethylene glycol) methyl ether methacrylate) and poly(4-vinylpyridine): synthesis and solution properties

Abstract

Block copolymers have attracted the interest of many research groups, especially due to self-assembly capability. Self-assembly can result in different morphologies and, consequently, systems with different properties. The combination of responsive polymers blocks results in copolymers, which properties, for example, in solution and self-assembly behavior are affected by environment conditions as temperature, pH, and others. Therefore, responsive block copolymers had been widely applied in biomedical area, particularly in drug delivery systems. In this context, this project aims the study of triblock copolymers based on poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA), a thermoresponsive polymer and poly(4-vinylpyridine) (P4VP), a pH-responsive polymer, as multiresponsive material. The response of these copolymers to variations in the environment in which they are present, in principle, can be modulated by composition and architecture. Reversible additionfragmentation chain-transfer polymerization technique (RAFT), which allows the achievement of copolymers with controlled composition and architecture, will be used to the copolymers POEGMA-b-P4VP-b-POEGMA and P4VP-b-POEGMA-b-P4VP synthesis. The self-assembly behavior of these triblock copolymers in solution will be studied in relation to changes at temperature, at pH, by solvent and concentration. The sol-gel behavior of these triblock copolymers will be also evaluated, aiming the achievement of a free-standing gel from this copolymers, altering only physical-chemical parameters and without the addition of crosslinking agent. (AU)