Abstract
This report describes a new simple method of reclaiming scrap tire by a phenylhydrazine-ferrous chloride system, which was presented at the International Rubber Conference held in Tokyo, October 14-17, 1975. The phenylhydrazine-ferrous chloride system considerably softened not only the truck tire scrap mainly composed of natural rubber but also the scrap tire of passenger cars mainly composed of SBR at room temperature in several hours. Vulcanization of these reclaims gave useful elastomers. The system was shown to be a very effective reagent for the reclamation of various types of synthetic rubber vulcanizates having C=C double bond at room temperature.The crosslink chain of vulcanized synthetic isoprene rubber was found to undergo the severance reaction by the system in the following order of easiness: polysulfide linkage>monosulfide linkage>carbon-carbon crosslink.Both the scission of main chain and the severance of crosslinks were found to be included in the degradation of sulfur vulcanizate of synthetic isoprene rubber by the system. Atmospheric oxygen was shown to be necessary for the above degradation reaction.
