Synthesis and characterization of coil-coil diblock copolymers containing catechol units via RAFT polymerization.

Abstract

We report the synthesis of poly(ethylene oxide)-b-poly(styrene-alt-N-(methoxycarbonyl) maleimide)) (PEG-b-Poly(St-alt-NMI)) diblock copolymers via reversible addition-fragmentation chain transfer (RAFT) polymerization and their modification with dopamines. Inspired by the key component of adhesive proteins in nature, we introduce dopamine units into the N-(methoxycarbonyl)maleimide units of the diblock copolymer backbone. Unlike the limitation on the types of coating substrates and leaching problems of previous coating methods with end-functionalized PEG, we demonstrate the universal immobilization of PEG-based diblock copolymer containing catechol units on various surfaces by using a simple dipping method. This dopamine incorporated block copolymers can be considered as a new type of PEGylation reagent on various types of surfaces. Measurement of contact angle and film thickness of the polymer coated substrates revealed that this new type of PEG diblock copolymer had superior adhesive ability to the existing methods. Also, interestingly, the diblock copolymers self-assembled into micelles of which size can be controlled by the composition of the solution, presumably due to its structural amphiphilic character.