Due to the global drive towards biodegradable products, trimethylolpropane [2-ethyl-2-(hydroxymethyl)-1,3-propanediol] (TMP) esters based on palm and palm kernel oils were synthesized, their lubrication properties evaluated, and their potential as base stock for biodegradable lubricants assessed. Two types of TMP esters were considered: palm kernel (PKOTE) and palm oil (PPOTE) TMP esters, derived from palm oil and palm kernel methyl esters, respectively. Lubrication properties such as viscosity, viscosity index (VI) and pour point (PP) were determined according to methods of the American Society for Testing and Materials. Wear and friction properties were evaluated using a four-ball test machine, while oxidative stability was studied with the Penn State Micro-oxidation thin-film test. High VI ranges between 170 to 200 were recorded for these base stocks. PP were relatively high, between 4 to -1 °C, but were improved to at least -33 °C in high oleic palm oil TMP esters. The effects of chemical structure and impurities on wear properties and oxidative stability were also studied. The presence of methyl esters was found to improve wear, but hydroxyl groups in mono-and diesters had negative effects at high concentrations. Differences in chemical structures of PKOTE and PPOTE were shown to affect friction and wear results. Both base fluids exhibit oxidative stability comparable to other high oleic base fluids.Keywords: Biodegradable lubricant, palm oil, palm kernel oil, trimethylolpropane esters.Correspondence: Robiah Yunus, Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia. Phone: +60-3-89466291/019-6969106, Fax: +60-3-86567099; e-mail: robiah@eng.upm.edu.my

A new type of rigid polyurethane foam was produced by incorporating oxazolidone heterocyclic rings on to polyurethane backbones. Epoxidized diethanolamides were synthesized by reacting palm oil blends of epoxidized palm olein and refined bleached deodorized palm kernel olein with diethanolamine to produce rigid polyurethane foams. Epoxides, retained in the diethanolamides, reacted with isocyanate during foam production in the presence of AlCl 3 -THF complex catalyst to form oxazolidone linkages in the polyurethane network. The carbonyl stretch of oxazolidone was identified at 1,750 cm -1 through Fourier Transform Infra Red analysis. Chemical modifications of the polyurethane network also improved the thermal and mechanical properties of the foams. In addition, isocyanate index 1.4 was determined to be the most suitable in the production of foams from this newly synthesized epoxidized diethanolamides.

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Kinetics of transesterification of palm-based methyl esters (POME) with trimethylolpropane (TMP) to polyol esters was investigated. A kinetic model of reaction was obtained by assuming a series of irreversible elementary reactions at various temperatures. The reaction rate constants were determined under limited conditions. The optimal ratios for k 2 /k 1 and k 3 /k 1 were 0.70-0.80 and 0.21-0.25, respectively. Both palm oil methyl esters (PPOME) and palm-kernel oil methyl esters (PKOME) were reacted with TMP by using sodium methoxide as catalyst. The POME-to-TMP molar ratio and catalyst weight percentage were held constant at 10:1 and 0.4%, respectively. The effects of temperature (70-110°C) and raw materials (PKOME and PPOME) were investigated and found to have a significant impact on the reaction kinetics. When using a large excess of POME and continual withdrawal of methanol via vacuum, the reaction reached completion in less than 20 min at 80°C. After removal of unreacted POME, the final product contained approximately 98 wt% triesters.

Palm oil based trimethylolpropane (TMP) esters are potential biodegradable base stocks for environmentally friendly lubricants. To improve the low-temperature properties of palm oil based TMP esters, which are well below the requirements set by the lubricants' manufacturers, the high oleic content palm oil based TMP ester with a pour point between −10 and −32 °C was synthesized. The synthesis of palm oil polyol esters was performed by transesterification of fractionated palm oil methyl esters with TMP using sodium methoxide as a catalyst. Nearly complete conversion to palm TMP triesters (98% w/w) was obtained. The palm oil methyl esters were fractionated at 150−180 °C and 0.1 mbar prior to the synthesis to reduce the saturated fatty acid content. The fractionation and reaction took place using the same experimental setup. The effects of composition on pour points, viscosity, and viscosity index of the high oleic content palm oil based TMP esters were also evaluated. The concentration of C16:0 methyl ester in the starting material should be below 10% w/w to ensure that the pour points of high oleic content palm oil based TMP esters are below −30 °C. In addition, the reaction conversion to triester must also be maintained above 90% w/w to produce TMP esters with excellent pour points. Operating temperature had a negligible effect on the reaction yield so long as the temperature was kept above 120 °C. There were small variations in the viscosities and viscosity index values of high oleic content palm oil based TMP, in the region of 50 cSt and 199, respectively.