Clay catalyst has received much attention to replace the homogeneous catalysts in the esterification re-action to produce fatty acid methyl ester as the source of biodiesel as it is low cost, easily available, as well as environmental friendly. However, the use of unmodified clay, in particular montmorillonite K10 (MMT K10), for the esterification of fatty acids showed that the acid conversion was less than 60% and this is not preferable to the production of biodiesel. In this study, synthesis of stearic acid methyl ester using Cu2+-MMT K10 (Cu-MMT K10) was successfully optimized via response surface methodo-logy (RSM) based on 3-variable of Box-Behnken design (BB). The parameters were; reaction time (5-180 minutes), reaction temperature (80-120 �C) and concentration of Cu2+ in MMT K10 (0.25-1 M). The use of RSM in optimizing the conversion of stearic acid was successfully developed as the actual experi-mental conversion of stearic acid was found similar to the actual values under the optimum conditions. The model equation predicted that the following conditions would generate the maximum conversion of stearic acid (87.05 % reaction time of 62 minutes, a reaction temperature of 80 'C and catalyst used is 1.0 M Cu-MMT K10. This finding can be considered as green catalytic process as it worked at moderate reaction temperature using low cost clay catalyst with a short reaction time.

Shape memory polyurethanes (SMPU) are one of the advanced materials that have potential applications in the field of biomedical particularly vascular stent. This paper studies the effect of incorporating palm oil polyol (POP) up to 40% molar ratio in place of petroleum-based polyol in the preparation of SMPU due to environmental concern. Polycaprolactone diol was utilized as the soft segment while 4,4?-diphenylmethane diisocyanate and 1,4-butanediol as the hard segments. The SMPU was prepared using two-step prepolymer method, and the fabricated samples were characterized to study the effect of POP on the thermal properties, tensile, and shape memory behavior of polyurethane. The results obtained have shown that SMPU with incorporation of POP showed good shape fixity (100%) and elongation at break (245%) up to 20% molar ratio of POP. The presence of dangling chains of fatty acid in POP was believed to enhance the flexibility of SMPU molecular chains by acting as a plasticizer. On the other hand, the shape recovery of SMPU remains high even at 40% molar ratio of POP, and the thermal stability of SMPU increased with the addition of POP. It is proposed that the synthesized POP-based SMPU is a suitable candidate for cardiovascular stent as they possessed desired thermal, mechanical, and shape memory properties. � 2018 John Wiley & Sons, Ltd.

Montmorillonite K10 (MMT K10), the major clay mineral commercially available can be treated to improve its properties and thus can be utilized for a broad range of organic reaction including esterification of fatty acids for biodiesel production. However, the use of unmodified MMT K10 in esterification of fatty acids showed that the acid conversion was less than 60 %. The aim of this study is to utilize available material i.e. MMT K10 modified with Cu2+, Al3+ and Fe3+ at various concentrations as catalyst for the esterification of acetic acid and stearic acid. The x-ray diffraction and elemental analysis of the materials were successfully characterized. After characterization, the materials were evaluated for the esterification of acetic acid and stearic acid with methanol. Prepared catalysts were able to give the highest acid conversion of up to 75% relative to the unmodified MMT K10 revealing the potential of M-MMT K10 as catalyst for esterification in biodiesel production. � Copyright International Association of Engineers.

Many countries produced biodiesel from crude vegetable oil. However, current vegetable oil feedstock to produce biodiesel slow the growth of biodiesel blend implementation due to the high cost of feedstock production. As a result, waste cooking oil (WCO) is claimed to be economic and readily available without cultivation and highly potential feedstock for high yield biodiesel. In this study, Fe-exchanged montmorillonite K10 (Fe-MMT K10) was employed as a catalyst in converting WCO to biodiesel. In comparison, Fe-MMT K10 was able to produce 95.26% biodiesel, which is higher than biodiesel produced using unmodified MMT K10 as catalyst and reaction without catalyst (38.39% and 29.50%, respectively). The full process of biodiesel production was carried out by response surface methodology (RSM) in conjunction with the central composite design (CCD) for statistically optimization and modelling. From the ANOVA, it was found that the production of biodiesel achieved an optimum level of 92.74% biodiesel at 134.07 °C, under a specific optimized condition of 6.32 h reaction time, 4.68 wt% of catalyst and 11.77:1 methanol to oil ratio.

The aim of this work is to develop a new type of polymer matrix which can be used to study the reactive intermediates produced from UV photolysis of metal carbonyl complexes measured with FTIR as well as UV-vis spectroscopy. The photochemistry of Cr(CO)6impregnated in Teflon-AF polymer with the presence of N2, CH4and even weak ligand i.e.Xe and He were conducted at extremely low temperature. Photolysis of Cr(CO)6under N2environment produces up to four carbonyl groups being replaced with the N2. Meanwhile, the photochemistry of Cr(CO)6under Xe and CH4produce the reactive complexes of Cr(CO)5(Xe) and Cr(CO)5(CH4)respectively. Teflon-AF was found to be the suitable matrix material as the �C�F� bond binds very weakly to the metal center. � 2016 Penerbit UTM Press. All rights reserved.