Synthesis and characterization of new bi-sensitive copoly(2-oxazolines)

Abstract

We synthesized new bi-sensitive statistical copolymers and A-B-A triblock copolymers from 2-cyclopropyl-2-oxazoline (CPOxa) and 2-methoxycarbonylethyl-2-oxazoline (MEtOxa) using 1,4-dibromobutene as a bi-functional initiating moiety. These new bi-sensitive polymers were obtained via quasi-living polymerization of the oxazoline monomers and subsequent hydrolysis of the methyl ester of MEtOxa. Their thermal conformational transitions in aqueous solution were between 30 and 60 °C and these values were dependent of the copolymer composition, polymer structure (statistical or block copolymer), and of the pH of the solution, where the polymers were dissolved. The achieved polymers could find application in biomaterial science, in microsystems and sensors, and as smart nanocarriers.