Synthesis of a pH- and thermo- responsive binary copolymer Poly(N-vinylimidazole-co-N-vinylcaprolactam) grafted onto silicone films

Abstract

This work focuses on the effects of gamma-ray irradiation conditions on the stimuli-responsiveness of silicone rubber (SR) substrates grafted with N-vinylcaprolactam (NVCL) and N-vinylimidazole (NVIM), modified by the simultaneously polymerization and grafting method, which is expected to result in valuable new applications in the near future. The modification of silicone rubber was carried out via γ-ray radiation in order to graft a binary copolymer, poly(N-vinylimidazole-co-N-vinylcaprolactam), by the pre-irradiation method, to obtain pH- and thermo-responsive materials. The grafting yield was found to be directly proportional to the dose and monomers concentration. The biomaterials were characterized by using Fourier-transform infrared attenuated total reflection (FTIR-ATR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and swelling; and their stimuli behavior was evaluated by lower critical solution temperature (LCST) and pH critical studies.