Synthesis of poly (ethylene glycol)-block-poly (acrylamide)-block-poly (lactide) amphiphilic copolymer through ATRP, ROP and click chemistry: Characterization, micellization and pH-triggered sustained release behaviour

Abstract

pH-responsive amphiphilic triblock copolymer derived from poly (ethylene glycol), poly (acrylamide) and poly (lactide) has been synthesized through the consecutive routes of ATRP, ROP and Click chemistry. Controlled nature of the triblock copolymer has been affirmed by the GPC analysis. Structural property and gelling nature of the copolymer have been investigated using FTIR, 1H/13C NMR spectral analyses and rheological characteristics. The synthesized copolymer is amphiphilic in nature that results to the formation of self-aggregation of the polymeric chains. The nanostructure micelle has been characterized further through AFM, FESEM and HR-TEM analyses. Encapsulation of fluorescence probe guest molecule (pyrene) into copolymer micelle and its release behaviour reveals that it is pH-stimulated and shows sustained release behaviour at pH 7.4.