JOURNAL OF POLYMER ENGINEERING

 Vol. 21, No. 6, 2001, page 559

A STUDY OF THE INTERACTIONS BETWEEN OLIGOAMIDEPHOSPHATE AND CURATIVES IN A SULFENAMIDE-ACCELERATED SULFUR VULCANIZING SYSTEM II. THE INTERACTION OF OLIGOAMIDEPHOSPHATE WITH N-CYCLOHEXYLBENZOTHIAZOLE-2-SULFENAMIDE

Todorka G. Vladkova and Milka G. Pankova

 University of Chemical Technology and Metallurgy, Sofia

8 Kliment Okhridski Blvd., 1756 Sofia, Bulgaria

 ABSTRACT

     The aim of our investigation was to clarify the mechanism of a specific vulcanization network formation when oligoamidephosphate (OAPh) is present in different rubber compounds. In a previous study we proved that OAPh interacts with zinc oxide and sulfur, but does not interact with stearic acid. We continued this study with the interaction of OAPh and sulfenamide accelerator, N-cyclohexylbenzothiazol-2-sulfenamide (CBS). It appears that the terminal ammonium group of OAPh forms an adduct with the benzothiazole fragment of the sulfenamide and the OAPh phosphate ion interacts with the cyclohexylamine fragment to form cyclohexylamine phosphate. Such interaction also takes place in the presence of zinc oxide and sulfur, in a triple OAPh/CBS/ZnO or four-fold OAPh/CBS/ZnO/S combination, but in these cases it is preceded by zinc salt formation with the terminal carboxyl group of OAPh. Sulfur bonds to a-methylene groups of the OAPh chain. These interactions form the basis for the specific vulcanization mechanism of the rubber compounds containing OAPh. They lead to a blockade of the CBS decomposition fragments in the corresponding salt and in this way stop the development of the process of N-nitrosamine formation.

P.O. Box 35010, Tel Aviv, Israel, 61350. Tel: 972-3- 562-8540; Fax: 972-3-562-8538

E-mail: h_freund@netvision.net.il; website: https://www.freundpublishing.com