108 research outputs found

    Sintesis sebatian hidroksi-eter minyak sawit olein

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    Sebatian hidroksi-eter-POo (80% hasil) disintesis melalui pembukaan gelang oksirana minyak sawit olein terepoksida (EPOo) secara alkoholisis. Hasil optimum pembukaan gelang oksirana (99.2%) dicapai dengan menggunakan asid sulfurik 3% v/bt pada suhu tindak balas yang tinggi (80oC) selama 30 minit masa tindak balas. Spektrum resonan magnetik nukleus-proton (1H-NMR) hidroksi-eter-POo telah menunjukkan kehadiran puncak proton pada karbon eter (3.2, 3.5 ppm) dan proton pada kumpulan hidroksil (4.8 ppm). Spektrum resonan magnetik nukleus-karbon (13C-NMR) hidroksi-eter-POo telah menunjukkan kehadiran puncak karbon yang terikat dengan kumpulan hidroksil (75 ppm) dan karbon pada karbonil kumpulan eter (72 ppm). Kelikatan kinematik hidroksi-eter-POo adalah 234.4 cSt (40oC) dan 28.1 cSt (100oC) dengan indeks kelikatan 156

    Electrochemical Behavior of Polycrystalline Copper in Aqueous Phosphate Buffered Solution During CO2 Reduction.

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    The redox processes occurring on the copper surface in phosphate buffered solution were investigated. The results show that the oxidation and the reduction of copper surface occur in a slow process with hydrogen evolution region proceeding at potential more negative than -1.0 V. It is found that the hydrogen evolution region was not affected by the anodic potential limits. The anodic film forms on the copper surface are reduced possibly in quasireversible manner. In CO2-saturated solution, the loss of copper to the solution increases due to the formation of copper soluble species. This process is further enhanced with the polarization process, where copper(I)-carbonyl forms to the bulk solution. The results also show that the electrochemical behavior of copper electrode is dramatically changed by the polarization process. The hydrogen evolution region is greatly depressed due to the CO2 reduction process. Consequently, the reduction of CO2 is not pronounced on the copper surface except for the electrode surface has which been polarized at high cathodic potential for a period of time

    Synthesis And Characterization Of Ester Trimethylolpropane Based Jatropha Curcas Oil As Biolubricant Base Stocks

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    Biolubricant production of ester trimethylolpropane (ET) was conducted via esterification of fatty acid (FA) of Jatropha curcas oil with trimethylolpropane (TMP). The condition for this reaction was as follows: temperature was 150°C, time of reaction was 3 hours, molar ratio of FA: TMP was 4:1, and 2 % w/w catalyst (based on weight of FA). Sulfuric acid was used as the catalyst in this reaction. The composition of ET was determined by gas chromatography (GC-FID). The ester group was confirmed by fourier transform infrared spectroscopy (FTIR) and the structure was confirmed by proton and carbon Nuclear Magnetic Resonance (1H-NMR and 13C-NMR) spectra. 55% of product was successfully synthesized in this research. The pour point of the product was observed as low as –30°C, flash point was >300 °C and viscosity was 79 cP

    Epoxidation of Palm Kernel Oil Fatty Acids

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    Epoxidation of palm kernel oil fatty acids using formic acid and hydrogen peroxide was carried out effectively using a homogeneous reaction. It was found that epoxidation reaction occurred optimally at a temperature of 40oC and reaction time of 120 minits. The oxirane conversion was the highest at 1.46mol and 0.85mol of hydrogen peroxide and formic acid respectively. It was found that a maximum of 99% relative conversion of ethylenic oxirane was obtained, similar to the conversion of iodine value. The formation of epoxide adduct of palm kernel oil fatty acids (FAPKO) was confirmed by 1H NMR and 13C NMR spectral analysis showed the disappearance of double bonds and replaced by epoxy group in the EFAPKO

    New stabilizers for polystyrene based on 2-N-salicylidene-5-(substituted)-1,3,4-thiadiazole compounds

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    AbstractThe photostabilization of polystyrene (PS) films by 2-N-salicylidene-5-(substituted)-1,3,4-thiadiazole compounds was investigated. The PS films containing concentration of complexes 0.5% by weight were produced by the casting method from chloroform solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PS with irradiation time were also tracked (using benzene as a solvent). The quantum yield of the chain scission (Φcs) of these complexes in PS films was evaluated and found to range between 3.31×10−6 and 7.89×10−6. Results obtained showed that the rate of photostabilization of PS in the presence of the additive follows the trend: SN>SC>SB>SI>SPAccording to the experimental results obtained, several mechanisms were suggested depending on the structure of the additive. Among UV absorption, peroxide decomposer and radical scavenger for photostabilizer additives mechanisms were suggested

    Improvement of Physicochemical Characteristics of Monoepoxide Linoleic Acid Ring Opening for Biolubricant Base Oil

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    For environmental reasons, a new class of environmentally acceptable and renewable biolubricant based on vegetable oils is available. In this study, oxirane ring opening reaction of monoepoxide linoleic acid (MEOA) was done by nucleophilic addition of oleic acid (OA) with using p-toluene sulfonic acid (PTSA) as a catalyst for synthesis of 9(12)-hydroxy-10(13)-oleoxy-12(9)-octadecanoic acid (HYOOA) and the physicochemical properties of the resulted HYOOA are reported to be used as biolubricant base oils. Optimum conditions of the experiment using D-optimal design to obtain high yield% of HYOOA and lowest OOC% were predicted at OA/MEOA ratio of 0.30 : 1 (w/w), PTSA/MEOA ratio of 0.50 : 1 (w/w), reaction temperature at 110°C, and reaction time at 4.5 h. The results showed that an increase in the chain length of the midchain ester resulted in the decrease of pour point (PP) −51°C, increase of viscosity index (VI) up to 153, and improvement in oxidative stability (OT) to 180.94°C

    Production of Chemoenzymatic Catalyzed Monoepoxide Biolubricant: Optimization and Physicochemical Characteristics

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    Linoleic acid (LA) is converted to per-carboxylic acid catalyzed by an immobilized lipase from Candida antarctica (Novozym 435). This per-carboxylic acid is only intermediate and epoxidized itself in good yields and almost without consecutive reactions. Monoepoxide linoleic acid 9(12)-10(13)-monoepoxy 12(9)-octadecanoic acid (MEOA) was optimized using D-optimal design. At optimum conditions, higher yield% (82.14) and medium oxirane oxygen content (OOC) (4.91%) of MEOA were predicted at 15 μL of H2O2, 120 mg of Novozym 435, and 7 h of reaction time. In order to develop better-quality biolubricants, pour point (PP), flash point (FP), viscosity index (VI), and oxidative stability (OT) were determined for LA and MEOA. The results showed that MEOA exhibited good low-temperature behavior with PP of −41°C. FP of MEOA increased to 128°C comparing with 115°C of LA. In a similar fashion, VI for LA was 224 generally several hundred centistokes (cSt) more viscous than MEOA 130.8. The ability of a substance to resist oxidative degradation is another important property for biolubricants. Therefore, LA and MEOA were screened to measure their OT which was observed at 189 and 168°C, respectively

    Lubricity Characterizations of Sebacic Acid Based Ester

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    The current study aimed to evaluate the effect of long-chain and branch alcohol on lubricity of sebacic acid based ester. Since currently synthesis of a new lubricant to improve the lubricity properties and quality of lubricant is increasing, in this study, sebacic acid esters were synthesized by the conventional esterification method with some modification using sulfuric acid (SA) as catalyst. Twelve samples of sebacic acid esters with different chemical structures were synthesized including di-2-octyl sebacate, didecyl sebacate, di-2 ethylhexanol sebacate, di-2-ethylbutyl sebacate and dioleyl sebacate. These diesters were tested in terms of their suitability as lubricant. The results showed that the pour point, flash point and oxidation stability were affected by liner and branch of the alcohol used. Di-2-ethylbutyl sebacate (D2EBS) and di-2-ethylhexanol sebacate (D2EHS) showed very low pour point at -44°C and -60°C respectively, while the same carbon number of dihexyl sebacate (DHS) and dioctyl sebacate (DOS) recorded high pour point at 8°C and 15 °C respectively. These differences were due to the presence of the branching. DOS recorded the highest oxidative stability at 290°C. However, there was a slight negative effect of the branching on the flash point

    Production Of Biolubricant Based On Jatropha Curcas Oil And Linear Alcohol Abstract

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    The use of oils and fats for lubrication purposes has been practiced for many years. This is starting that realized since the mineral oil in a limited number. In this research, the production of biolubricant based plant oil is Jatropha Curcas oil and linear alcohol. Oil produced from the fruits is 44.30%. However, oxidative stability and low pour point are problem for biolubricant. The method used to overcome this problem is epoxidation process and ring opening. Epoxidation process successfully carried out by testing the oxyrane value and also FTIR analysis, where the peak of alkenes is 3007 cm-1. Epoxy peak appeared at 843 and 824 cm-1, which is testament to the success of epoxy ring is formed. Ring opening proved successful with FTIR analysis of the appearance of hydroxyl groups at the peak of 3444 cm-1, the peak of ether in 1097 cm-1, and the loss of epoxy peak. Bioubricant which is produced in the form of alcohol ether is to produce five types of biolubricant, which are decanol ether, dodecanol ether, tetradecanol ether, hexadecanol ether and octadecanol ether. 1H dan 13C  NMR analysis is also succeeded in proving the presence of key functional groups for the fifth type of biolubricants. In terms of viscosity and flash point, lubricant successful enhanced oil-based plants, but not succeded to reduce the pour point
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