The Vulcanization of Rubber by Diazoamino Compounds

Vulcanizing agents for rubber can be classified in the following six types: (1) Sulfur, including α-sulfur, β-sulfur, γ-sulfur, precipitated sulfur, and nascent δ-sulfur. (2) compounds containing sulfur, e. g., sulfur chloride, sulfur iodide, sulfur dioxide, phosphorous sulfides, hydrogen persulfides, nitrogen sulfide, and alkaline polysulfides. (3) elements of the sulfur group and their compounds, e. g., selenium, tellurium, selenium sulfur chloride, and selenium diethyldithiocarbamate. (4) halogens and halogenated compounds, e. g., chlorine, bromine, iodine, hypochlorous acid, hypochlorites, and benzoquinone dichloride. (5) oxygenated compounds capable of liberating nascent oxygen at vulcanizing temperatures, e. g., persulfates (such as ammonium persulfate), peracids (such as perbenzoic acid), nitro compounds (such as 1,3,5-trinitrobenzene, tetranitronaphthalene, and nitrocyclohexane in the presence of metallic oxides), and organic peroxides (such as benzoyl peroxide). (6) derivatives of rubber, e. g., rubber ozonide, chlorinated rubber, brominated rubber, and rubber hydrochloride.