Is methanol really a bad solvent for poly(n-butyl methacrylate)? Low dispersity and high molecular weight polymers of n-butyl methacrylate synthesised via ATRP in anhydrous methanol

Despite it being used widely as a precipitant for poly(n-butyl methacrylate), p(nBuMA), Cu-catalysed atom transfer radical polymerisation has been conducted in anhydrous methanol. Successful polymerisation (50 wt% monomer) was achieved at 60 °C and 25 °C, reaching high molecular weights (up to M_n = 75 880 g mol⁻¹), low dispersities (as low as Đ = 1.02) and high conversions without measurable molecular weight broadening. Cloud point behaviour (upper critical solution temperature) and the role of monomer co-solvency are studied and polymerisation comparisons are made with ATRP in isopropanol and in methanol with different ligands.