Synthesis of gradient copolymers with simultaneously tailor-made chain composition distribution and glass transition temperature by semibatch ATRP: From modeling to application

Abstract

Recent studies have demonstrated that gradient copolymers exhibit unique thermal properties. Although these properties can be determined by copolymer composition, other factors such as chain and sequence lengths and their distributions can also influence them. Accordingly, the synthesis of gradient copolymers requires simultaneously tailor-made chain structure and thermal properties. In this work, we carried out a systematic study on the preparation of poly(methyl methacrylate-grad-2-hydroxyethyl methacrylate) [poly(MMA-grad-HEMA)] with synchronously tailor-made chain composition distribution and glass transition temperature (Tg) through semibatch atom transfer radical polymerization. First, a comprehensive model for simultaneously predicting gradient copolymer microstructure and Tg was presented using the concept of pseudo-kinetic rate coefficients and Johnston equation. The model was validated by comparing simulation results with the classical reference data. Furthermore, the model was used to guide the experimental synthesis of the poly(MMA-grad-HEMA) gradient copolymers potentially as excellent damping material. The thermal properties of these gradient copolymer samples were evaluated. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012