Published November 2010
Synthesis of alkaline-earth salts of hydroxyalkylbenzyl sulphonic acid and their investigation as lubricant additives
A. N. AghayevThis article deals with the results of investigations on synthesizing of alkaline-earth metals such as magnesium, calcium, strontium, barium of hydroxyalkylbenzyl sulphonic acid and studying the effect of the nature of cation on their efficiency as lubricant additives. The parent raw material for producing the additives was alkylphenol obtained by alkylation of phenol with ethylene oligomers fr. 210310 оС (R=C12-C18) in the presence of benzenesulphonic acid as catalyst. During the sulphonation of alkylphenol as a sulphonating agent a nonaggressive, cheap and available reagent bisulphate derivative of formaldehyde, namely, hydroxymethane sulphonate of sodium, which prevents the formation of difficultly utilized liquid waste sludge, has been used. It was shown that synthesized hydroxyalkylbenzyl sulphonates of alkaline-earth metals fully dissolve in the oil and characterized by good physico-chemical and functional properties. Being the additives of multifunctional action, on introduction into the M-11 lubricant in the 5 % concentration, they markedly improve its detergent, dispersive, anticorrosive properties, oxidation resistance and thermal oxidation stability. Depending on the nature of catoin the synthesized additives show different efficiency. By the efficiency of detergent-dispersive action and anticorrosive properties hydroxyalkylbenzyl sulphonates of magnesium and calcium are superior to appropriate sulphonates of Sr and Ba. Thus, the dispersive properties of Mg and Ca salts are respectively 65 and 60 % whereas these indices for Sr and Ba are 52 %. By oxidation resistance and thermal oxidation stability Sr and Br containing additives possess higher efficiency than Ca and Mg sulphonates. The obtained results can be successfully used while forming additive package for motor oils.
