Application of spin trapping technique to radical polymerization, 13 Polymerization of methyl methacrylate with 1,2,3,10a-tetrahydrophenanthrene-1,2-dicarboxylic anhydride

The polymerization of methyl methacrylate (MMA) with 1,2,3,10a-tetrahydrophenanthrene-1,2-dicarboxylic anhydride (TH) ( 10 ), which is a stable Diels-Alder adduct of α-vinylnaphthalene and maleic anhydride, was investigated by kinetic and spin trapping methods. TH could induce radical polymerizations of MMA and methyl acrylate with a considerably high rate, and the rate of polymerization (R_p) of MMA was found to follow the equation: R_p = k[TH]^0,3 [MMA]^1,6. The overall activation energy and the chain transfer constant to TH for this polymerization were determined to be 47,7 kJ/mol and 0,52, respectively. From these results, an initiation mechanism involving a hydrogen-transfer from TH to MMA was proposed, which is similar to Mayo's initiation mechanism for the thermal polymerization of styrene. To confirm this mechanism, the spin trapping technique was applied. The results obtained regarding the trapping of the initiating radicals supported this hydrogen-transfer initiation mechanism.