Polymerization of allyl compounds. V. Inhibition by nitro compounds

The effect of various nitro compounds on the peroxide‐induced short‐chain polymerization of allyl acetate has been investigated. Of the compounds studied, sym‐trinitrobenzene is the most active as a retarder. Nitromethane and dinitrodurence were found to be less effective than aromatic nitro compounds which have replaceable nuclear hydrogen atoms but both exerted a measurable retarding influence on the polymerization reaction. It is found that trinitrobenzene reacts with a minimum of 5.9 radicals per molecule. This and other data are discussed in connection with the hypothesis that radicals react by an alkylation mechanism. An alternative mechanism involving attack on the nitro group itself is suggested.