Cyclopolymerization vinyl methacrylate

It has been suggested that certain 1,5-dienes including o-divinylbenzene (23),156 vinyl acrylate (24, X 11) and vinyl methacrylate (24, X CH )120 may also undergo cyclopolymerization with a monomer addition occurring prior to cyclization and formation of a large ring. However, the structures of these cyclopolymers have not been rigorously established. 

Chiral induction was observed in the cyclopolymerization of optically active dimethacrylate monomer 42 [88], Free-radical polymerization of 42 proceeds via a cycliza-tion mechanism, and the resulting polymer can be converted to PMMA. The PMMA exhibits optical activity ([ct]405 -4.3°) and the tacticity of the polymer (mm/mr/rr =12/49 / 39) is different from that of free-radical polymerization products of MMA. Free-radical polymerization of vinyl ethers with a chiral binaphthyl structure also involved chiral induction [91,92]. Optically active PMMA was also synthesized through the polymerization of methacrylic acid complexed with chitosan and conversion of the resulting polymer into methyl ester [93,94]. 

More examples have been quoted of special growth reactions for molecules having two carbon-carbon double bonds. Cyclopolymerization occurs for diallylaminomethyl phenols, allyl esters of unsaturated acids, 2-(2-vinyl-phenoxy)ethyl methacrylate and acrylate, 2-divinylbenzene and some silicon-containing monomers. - Polymerizations of p-xylylene and its derivatives have been considered further. - The radical polymmzation of some disubstituted vinylcyclopropanes has been represented as shown in equation (2), where X and Y=CN or COjEt. The involvement of the ring must be connected with stabilization by the substituents of the product radical. 

The polymerization of acrylic and methacrylic anhydride is interesting because linear polymers can be obtained in contrast to the cross-linked networks usually formed from difunctional vinyl monomers [588-590]. In a cyclopolymerization reaction, alternating... 

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