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 endcapped 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.