Abstract
In the nature of non-staining antiozonants, a new class of compounds, 1,1,4-derivatives of thiosemicarbazide, are proposed. The mechanism of reaction of thiosemicarbazide derivatives with ozone is analogous to the mechanism of this reaction with thiourea derivatives. Within this, the rate constant of the initial reaction of the thiosemicarbazide derivatives with ozone is somewhat higher than that of the thiourea derivatives. 1,1,4-Trialkyl-substituted thiosemicarbazides appear to be the most effective antiozonants, not changing the color of light vulcanizates. Of the investigated compounds, 1,1,4-tributylthiosemicarbazide, being distinguished by a large protective effect against ozone, inhibiting activity in the process of heat aging of the vulcanizates, and lesser ability for leaching out of the vulcanizates by water than tributylthiourea, presents the greatest practical interest.
