Synthesis of imidazole end-capped poly(n-butyl methacrylate)s via atom transfer radical polymerization with a new functional initiator containing imidazolium group

The synthesis of imidazole end-capped poly(n-butyl methacrylate)s via atom transfer radical polymerization (ATRP) is reported. n-Butyl methacrylate (n-BMA) was polymerized in isopropyl alcohol (IPA) at different temperatures via ATRP using a new N-heterocyclic functional initiator (1-α- bromoisobutylimidazole, BrBI) in the presence of CuBr/2,2'-bipyridine (bpy) as the catalyst. With this new initiating system, a successful ATRP of n-BMA was carried out, and imidazole end-capped polymers with predetermined molecular weights and low polydispersities (1.1<PDI<1.3) were obtained at low polymerization temperature (below 80°C). Furthermore, the dependence of both the rate of polymerization and PDI on temperature gave the optimal reaction temperature (50°C). However, at elevated temperature (especially above 80°C), some different phenomena appeared in the polymerization: the conversion of monomer remains constant after reaching a maximum value (20%-30%), and the higher the temperature, the lower the conversion obtained.