Biolubricant production from palm stearin through enzymatic transesterification method

The present study aims to develop environmentally benign lubricant from by-product of palm oil processing through enzymatic reaction. Candida antartica lipase was employed as catalyst to transesterified reaction between palm stearin and methanol in a solvent-free system. The reaction parameters were varied in terms of molar ratio of methanol-to-palm stearin (3:1 to 8:1), temperature (between 40 and 70 °C), time (2–12 h)and concentration of catalyst (from 2 to 10 wt.%). Enzymatic transesterification demonstrated around 95.26% maximum yield of palm stearin methyl ester under the following conditions: 4:1 methanol-to-PS molar ratio, reaction temperature of 60 °C, reaction time of 8 h and 6.0 wt. % of lipase concentration. The Structural modification of palm stearin resulted in improvement in both physicochemical and tribological properties. The produced biolubricant demonstrated superior viscosity index (>120)and friction properties over commercial mineral oil-based lubricant. This study showed that lubricant derived from palm stearin has a great potential to be used as a base stock in regard to favourable biodegradability and tribological performance

The Effect of Graphene Oxide and SEBS-g-MAH Compatibilizer on Mechanical and Thermal Properties of Acrylonitrile-Butadiene-Styrene/Talc Composite

In this study, acrylonitrile butadiene styrene (ABS)/talc/graphene oxide/SEBS-g-MAH (ABS/Talc/GO/SEBS-g-MAH) and acrylonitrile butadiene styrene/graphene oxide/SEBS-g-MAH (ABS/GO/SEBS-g-MAH) composites were isolated with varying graphene oxide (0.5 to 2.0 phr) as a filler and SEBS-g-MAH as a compatibilizer (4 to 8 phr), with an ABS:talc ratio of 90:10 by percentage. The influences of graphene oxide and SEBS-g-MAH loading in ABS/talc composites were determined on the mechanical and thermal properties of the composites. It was found that the incorporation of talc reduces the stiffness of composites. The analyses of mechanical and thermal properties of composites revealed that the inclusion of graphene oxide as a filler and SEBS-g-MAH as a compatibilizer in the ABS polymer matrix significantly improved the mechanical and thermal properties. ABS/talc was prepared through melt mixing to study the fusion characteristic. The mechanical properties showed an increase of 30%, 15%, and 90% in tensile strength (TS), flexural strength (FS), and flexural modulus (FM), respectively. The impact strength (IS) resulted in comparable properties to ABS, and it was better than the ABS/talc composite due to the influence of talc in the composite that stiffens and reduces the extensibility of plastic. The incorporation of GO and SEBS-g-MA also shows a relatively higher thermal stability in both composites with and without talc. The finding of the present study reveals that the graphene oxide and SEBS-g-MAH could be utilized as a filler and a compatibilizer in ABS/talc composites to enhance the thermo-mechanical stability because of the superior interfacial adhesion between the matrix and filler

Public Awareness and Practices Towards Self-Medication with Antibiotics Among Malaysian Population: Questionnaire Development and Pilot Testing

Not Availabl