Abstract Prevulcanization inhibitors based on triazines can be prepared. In each case the triazine ring is amino-substituted such that one or two of the amino hydrogen atoms per amino-group are alkylthio- or arylthio-substituted. The new triazine-derived prevulcanization inhibitors are extremely active in accelerated sulfur vulcanization of diene rubbers (e.g., NR or SBR). Differing accelerators or accelerator systems may require different triazine-derived prevulcanization inhibitors for best results. Provided that the reactivity of the inhibitor is sufficiently near the ideal, its weight-basis activity is greatest when its equivalent weight per S—N bond is least. Overall, hexakis(cyclohexylthio)melamine and especially hexakis(isopropylthio)melamine are the most effective premature vulcanization inhibitors tested, on an equal-weight basis.