Method of free radical polymerization of copolymerization of (meth)acrylic and vinyl monomers under control and (co)polymer produced thereby

PROBLEM TO BE SOLVED: To obtain a (co)polymer excellent in resistance to thermal decomposition by polymerizing or copolymerizing a monomer or monomers in the presence of an initiation system contg. a free-radical generator other than a bromoolefin and a catalyst comprising a Pd complex having an oxidation number of 0 and represented by a specific formula. SOLUTION: A Pd salt (e.g. Pd acetate), a ligand (e.g. triphenylphosphine), and a solvent (e.g. toluene) are charged into a reactor to form a Pd complex having an oxidation number of 0 and represented by the formula: Pd(0)L<1> L<2> L<3> L<4> [wherein L<1> to L<4> are each a ligand such as PRR'R'' (wherein R, R', and R'' are each 1-14C alkyl, etc.)]. Then, a monomer (e.g. methyl methacrylate) is added to the reactor followed by the addition of a free-radical generator (e.g. CCl4 ) in a molar ratio of Pd to the generator of 0.01-100.; The contents in the reactor are heated to 40-90 deg.C and stirred for a certain time to conduct the polymn. The reaction mixture is diluted with toluene, etc., filtered, and condensed under a reduced pressure. The resultant polymer soln. is poured into methanol, etc., and the resultant precipitate is filtered, washed, and dried to give a polymer having a number average mol.wt. of 400-10,000,000g/mol and a polydispersity lower than 2.