Alkylphenol derivatives of the polymer of thiocyanic acid and 5-amino-1,2,4-dithiazole-3-thione as an effective additives to fuels and lubricants

Abstract

For ensuring the operation of the mechanisms at high temperatures and pressures, it is necessary to use both stable base oils and effective additives in the composition of the lubricants. In the research, antioxidative and anticorrosive properties were identified in the oils of the condensation products of the alkylphenols with paraformaldehyde and thiocyanic acid polymer. The condensation products of the 5­amino­1,2,4­dithiazole­3­thione (Xanthane Hydride) with the 2,6­di­tert­Butylphenol and paraformaldehyde were investigated. A mixture of the products was obtained in the solution of the glacial acetic acid where the ratio of the 5­amino­1,2,4­dithiazole­3­thione and 2,6­di­tert­Butylphenol fragments is 1:1 and 1:3, respectively. An assumption about the structure of the substances was set up on the basis of the chemical and spectral data. For the compound with the empirical formula C 19 H 27 N 2 O (3 –5) S 3 the structure containing a residue of the 2,6­di­tert­Butylphenol and one heterocyclic fragment was proposed. For the compound with the empirical formula C 43 H 65 N 2 O (3 –5) S 3 the structure containing three residues of the 2,6­di­tert­Butylphenol was proposed. It was found that the products with a high content of the 2,6­di­tert­Butyphenol residues dissolve in the oils best of all. It was also found that alkylphenol derivatives of the thiocyanic acid and Xanthane Hydride are promising inhibitors of the corrosion and oxidation of the fuels and lubricants. The technique of the 5­amino­1,2,4­dithiazole­3­thione synthesis was improved. It was determined that it is better to synthesize it by treating an aqueous solution of the ammonium thiocyanate with the concentrated hydrochloric acid (instead of the sulfuric acid) in equimolar proportions at the temperature of 5–15 C. At the same time, the output of the aim product does not decrease and it can be easier purified.