The importance of solvent polar character on the synthesis of PMMA-b-PBA block copolymers by atom transfer radical polymerization

The synthesis of diblock copolymers using atom transfer radical polymerization (ATRP), of methyl methacrylate (MMA), and butyl acrylate (BA), is reported. These copolymers were prepared from bromo-terminated macroinitiators of poly(MMA) and poly(BA), using copper chloride, CuCl,/N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA), as catalyst system, at 100°C in bulk and in benzonitrile solution. The block copolymers were characterized by means of size exclusion chromatography (SEC), and 1H-NMR spectroscopy. The SEC analysis of the synthesized diblock copolymers confirmed the importance of solvent on the molecular weight control. In addition, differential scanning calorimetry (DSC), measurements were performed, showing for all the copolymers a phase separation.