Acrylamidevinyl acetate copolymer as a new UCST copolymer: Phase transition and aggregation behavior; an experimental and theoretical study

Abstract

A high sensitive upper critical solution temperature (UCST) copolymer was synthesized through free radical copolymerization with acrylamide (AAm) and vinyl acetate (VA). The UCST behavior is due to a combination of hydrogen bonds and electrostatic potentials between copolymer chains. Turbidimetry, dynamic light scattering, and rheology studies were used to determine the phase transition and aggregation behavior. It is indicated that copolymer with 80% AAm has a phase transition temperature between 38 and 38.2 °C, which is suitable for releasing fever medicine. Also, the temperature gradient for the complete dissolution of the copolymer is 2 °C. The molecular dynamics simulations at a molecular level confirmed the experimental results and indicated that aggregation of copolymer chains below UCST temperature had increased binding energy between polymer chains. The low cytotoxicity and its desirable UCST behavior make the copolymer promising for biomedical applications in the future.