Abstract
The hydrocarbon of rubber, which contains one ethylene linkage or double bond per isoprene unit, has such a structure that it is very sensitive to the action of oxygen, and the investigations of Farmer have shown clearly the part played by the α-methylene carbon atom in the process of oxidation. Since the rubber hydrocarbon can be made to react with compounds which unite directly with it, an attempt was made to find out what influence any changes of this kind might have on the oxidiazbility of rubber. The reagents chosen were saligenol and maleic anhydride. According to Cunneen, Farmer, and Koch, saligenol attaches itself to double bonds, with formation of a chromanic nucleus (I), the nature of which the present authors have examined and confirmed by ultraviolet spectrography of the compounds prepared. In the case of maleic anhydride, Delalande has shown that this compound and also related compounds, such as maleic imide, can combine according to the substitutive addition mechanism described by Alder, with the formation of a molecule of type (II). The reactions were carried out with exclusion of air, in accordance with the technique of Moureu and Dufraisse on benzene solutions of purified crepe rubber, and in the absence of a catalyst.