POLYMERIZATION IN SOLUTION AS A WAY TO OPTIMIZE THE SYNTHESIS OF BETA-DIKETONATE MACROINITIATORS BASED ON POLYMETHYLMETHACRYLATE

Abstract

The polymerization of methyl methacrylate initiated by Co (II) 5-methyl-5-hexene-2,4-dionate (MHD-Co) solution in dimethylformamide, methyl ethyl ketone and toluene has been studied. It is shown that polymerization does not take place in the solution of dimethylformamide due to the formation of inactive complexes «β-diketonate-solvent». Maximal polymerization rate has been observed in methyl ethyl ketone. The polymerization rate increases with decreasing of initiator concentration due to the MHD-Co inhibitory effect at high concentrations of chelate. The optimal concentration range of MHD-Co for polymerization initiation of methyl methacrylate in methyl ethyl ketone is 1,0-2,5×10-3 mol/l. The differences are noted in the behavior of the MHD-Co which chelate ring is conjugated with the double bond of the ligand, in comparison to cobalt 3-allylpentane-2,4-dionate where such conjugation is absent. The synthesized products are soluble in the monomers, they have a large number of metal chelate groups and can be used as macroinitiators in the preparation of branched and graft polymers. The total molecular weight of the grafted chains is much longer than the main chain.

Keywords

• вініл-бета-дикетонати
• радикальна полімеризація
• метилметакрилат
• макроініціатори