SPONTANEOUS COPOLYMERIZATION OF 1,3-CYCLOHEXADIENE WITH POLAR VINYL MONOMERS

Experimental data are presented which show that in the reactions of 1,3-cyclohexadiene(1,3-CHD) with polar vinyl monomers, CH//2:C(X)Y (X is -CN and -CO//2CH//3; Y is -Cl,-H, and -CH//3), the two alpha -chlorosubstituted monomers underwent rapid spontaneous copolymerization, accompanied by the formation of a small amount of cycloadduct. Both polar monomers also gave predominantly copolymers in the reaction with 1,3-cycloheptadiene(1,3-CHpD) in lower yield. 1,3-Cyclooctadiene (1,3-COD) reacted only with alpha -chloroacrylonitrile (CAN) to give a copolymer, while only cycloaddition took place in systems involving cyclopentadiene(CPD) as diene. The activation energies for the copolymerizations of 1,3-CHD with CAN and MCA in benzene were determined to be ca. 6. 6 and 9. 6 kcal/mole, respectively. Based on the results in the present and preceding studies for systems involving 1,3-cyclodienes and acceptor monomers, the relationship between the cycloaddition and the spontaneous copolymerization is discussed.