The Vulcanization of Rubber with m-Dinitrobenzene
Abstract The literature referring to the vulcanization of rubber with m-dinitrobenzene indicates the present undeveloped state of knowledge of the reaction and of the most favorable conditions for its employment. Much is vague and even contradictory. Ostromislensky (J. Russ. Phys.-Chem. Soc., 47, 1462 (1915)) stated that certain nitro compounds are capable of vulcanizing rubber in the absence of auxiliary substances, and that the products of vulcanization are superior in some respects to sulfur vulcanizates; tensile strengths obtained were comparable with those of sulfur vulcanizates; aging properties were found to be good; color and finish were better than those of sulfur vulcanizates. On the other hand, Porritt (J. Soc. Chem. Ind., 35, 986 (1916)), and Stevens (J. Soc. Chem. Ind., 36, 107 (1917)) failed to confirm these statements, but agreed that the presence of litharge is beneficial. Again in 1929, Ostromislensky (India Rubber World, 80, 55 (1929)) confirmed his original report, stating that he believed that this form of vulcanization is due to an action between rubber and the oxygen of the nitro compound. Blake (Ind. Eng. Chem., 22, 7 (1930)) stated that vulcanization of rubber with dinitrobenzene involves a monomolecular chemical reaction between rubber and dinitrobenzene, in which, of the 6 per cent dinitrobenzene, practically all of the nitrogen combined with the rubber. The end-product of the reaction appears to be a soft vulcanized rubber; no one has claimed to be able to produce an ebonite by the use of this reagent.