Soybean Oil-Based Lubricants:  A Search for Synergistic Antioxidants

Abstract

Vegetable oils can contribute toward the goal of energy independence and security due to their naturally renewable resource. They are promising candidates as base fluids for ecofriendly lubricants because of their excellent lubricity, biodegradability, good viscosity−temperature characteristics, and low evaporation loss. Their use, however, is restricted due to low thermo-oxidative stability and poor cold-flow behavior. This paper presents a systematic approach to improve their oxidation behavior by searching for a suitable additive combination. The study of antioxidant/antiwear additive synergism was investigated on a set of four antioxidants and three antiwear additives in vegetable oils using pressure differential scanning calorimetry (PDSC) and a rotary bomb oxidation test (RBOT). The results indicate that dialkyldithiocarbamate antioxidant performed better than diphenylamine and hindered phenol. The zinc dialkyldithiocarbamate antioxidant showed excellent synergism with antiwear additive antimony dithiocarbamates.

Evaluating water miscible deep eutectic solvents (DESs) and ionic liquids as potential lubricants

“…However, their drawbacks are associated with their high sensitivity to oxidation, hydrolysis and high pour points. 4,5 There are, however several polyalkylene glycol based water miscible lubricants which are also available although they have tended to be used for specialist applications. 6 While most lubricants are non-polar and have low surface tension there have recently been a significant number of publications using ionic liquids as lubricants.…”

Thermal Processes in Fats and Oils

“…Entre eles, podemos citar cosméticos, saneantes, tintas, solventes, e até mesmo diferentes biocombustíveis que podem ser utilizados em motores de combustão interna. [1][2][3] O principal constituinte dos OGs são moléculas conhecidas como acilglicerídeos, que são ésteres do glicerol e ácidos graxos, iguais ou diferentes. Dependendo do número de ácidos graxos esterificados com o glicerol têm-se triacilglicerídeos, como ilustrado na Figura 1, diacilglicerídeos ou monoacilglicerídeos.…”

Tribological evaluation of environmentally friendly ionic liquids derived from renewable biomaterials

“…Generally, environmentally friendly lubricants are divided into two categories according to their raw material sources. The primary environmentally friendly lubricants are derived from nature resources and are utilized in the modern industry, e.g., natural vegetable oils [9], chemically modified vegetable oils [7,8], genetically modified vegetable oils, and synthetic lubricants derived from biomaterials [10−12]. On the other hand, petrochemical-derived lubricants with good biodegradability are considered as the second type of environmentally friendly lubricants, e.g., synthetic esters, polyether, and low-viscosity polyalphaolefins [1].…”