Polymerization of Methyl Methacrylate Initiated byjributylborane-Pyridine System

The polymerization of methyl methacrylate (MMA) by the catalysts systems of tributylborane (TBB) with pyridine and its derivatives, such as hydroxypyridine, cyanopyridine, nicotinic acid, nicotinamide, nicotinic ester, picoline, lutidine and quinoline was studied. The relative initiating activities of the pyridine and its derivatives were found to be in the following order: nicotinic acid> nicotinic ester> nicotinamide> pyridine>3-hydroxypyridine>3-cyanopyridine> quinoline > 3-picoline > acridine > 2, 6-lutidine In the polymerization of MMA initiated by TBB/methyl nicotinate (MN) system, the rate of polymerization was found to be proportional to the concentration of MMA and to the square root of TBB/MN concentrations, respectively, and the apparent activation energy was 4.1 kcal/ mol. And the reaction of TBB with pyridine was also studied by NMR and ESR methods. From these results, it was found that the polymerization proceeds via a radical mechanism involving a co-ordination between TBB and pyridine or its derivatives.