Studies on the Aging Characteristics of Base Oil with Amine Based Antioxidant in Steel-on-Steel Lubricated Sliding

Abstract

An industrial base oil, a blend of different paraffin fractions, is heated to 130 °C (1) in the ambient and (2) for use as a lubricant in a steel pin on a steel disk sliding experiment. The base oil was tested with and without test antioxidants: dimethyl disulfide (DMDS) and alkylated diphenylamine (ADPA). Primary and secondary oxidation products were monitored continuously by FTIR over a 100 h period. In addition, friction and wear of the steel pin were monitored over the same period and the chemical transformation of the pin surface was monitored by XPS. The objective of this work is to observe the catalytic action of the steel components on the oil aging process and the efficacy of the antioxidant to reduce oxidation of oil used in tribology as a lubricant. Possible mechanistic explanations of the aging process as well as its impact on friction and wear are discussed.

Evaluation of Tribological Properties of Sulfur- and Phosphorous-Free Quinolinium Salts and Their Correlation with Quantum Chemical Parameters

“…[1][2][3][4][5][6] The organic compounds used as antiwear additives usually contain active elements like nitrogen, 7-9 sulfur, 10,12 phosphorous, 13,14 boron, 15,16 halogens 17 and metals [1][2][3][4][5] which interact with sliding surfaces to form a tribochemical film and thereby reduce friction, wear and increase the life of a machine. These antiwear additives have also been used as antioxidants, [18][19][20] corrosion inhibitors 21,22 and extreme pressure agents. [2][3][4] A literature survey shows that among inorganic compounds, extensive studies have been made on tribological behavior of zinc, molybdenum and lanthanum complexes of dithiohydrazodicarbonamides, 3 dithiocarbamates, 4 triphenylphosphorothionate 5 and dialkyldithiophosphate.…”

Crystal structure of bis(4-(2-phenylpropan-2-yl)phenyl)amine, C30H31N

“…Bis(4-(2-phenylpentan-2-yl)phenyl)amine, is a high-temperature chain termination agent, which has been widely applied in the synthesis of lubricating oils [4,5]. Bis(4-(2-phenylpentan-2-yl)phenyl)amine was synthesized by electrophilic alkylation of diphenylaminde and 2-phenyl-1-propene using acid clay as catalyst [6].…”

Synthesis and evaluation of a protic ionic liquid as a multifunctional lubricant additive

“…Primary antioxidants act as a "radical scavengers" reacting quickly with free radicals during the propagation phase and slowing down the oxidation process by forming new, more stable radicals. Secondary antioxidants react with peroxides and are responsible for breaking the cycle, preventing branching and further propagation [35]. ZDDP is a typical secondary antioxidant additive that reacts with hydroper peroxides and peroxy radicals and is effective for quenching the hydrocarbon oxidation chain reactions [29].…”