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Physical and chemical modification of zinc carboxylate‐containing lubricants by molecular structure changes
Author(s) -
Andor J. A.,
Berkesi O.,
Dreveni I.,
Varga E.
Publication year - 1999
Publication title -
lubrication science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.632
H-Index - 36
eISSN - 1557-6833
pISSN - 0954-0075
DOI - 10.1002/ls.3010110202
Subject(s) - carboxylate , zinc , chemistry , molecule , hydrocarbon , solvent , chemical structure , organic chemistry , chain (unit) , polymer chemistry , physics , astronomy
Twenty‐two samples of zinc carboxylates were prepared from saturated, non‐cyclic carboxylic acids with systematically altered hydrocarbon chain structures under well‐defined conditions. Essential temperature‐ and solvent‐induced changes concerning the coordination of the carboxylate group are shown using selected prepared samples, and general rules for systems containing zinc carboxylates in nonpolar media are presented. It is shown that there are three possible structural forms for zinc carboxylates: polymeric sheet, polymeric chain, and closed tetranuclear oxo complex molecules. These forms are closely related through their physical and chemical transitions. The results show that the spatial structure of the hydrocarbon chain is a crucial factor, besides physical and chemical conditions, limiting the possible forms of zinc carboxylates present in the system. The principles presented enable us to predict and design the behaviour of a system containing zinc carboxylate additives.