Clay catalyst has received much attention to replace the homogeneous catalysts in the esterification reaction 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 methodology (RSM) based on 3-variable of Box-Behnken design (BB). The parameters were; reaction time (5180 minutes), reaction temperature (80-120 degrees 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 experimental 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 degrees 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. Copyright (C) 2018 BCREC Group. All rights reserved.

Lard consumption is forbidden for Muslim people and researches have been done to differentiate lard from other fats for Halal authentication. Therefore, this study was conducted to differentiate lard from other edible fats after heating treatments using Fourier transformed infrared spectroscopy (FTIR) and multivariate data analysis techniques. Five samples of fats from different sources; lard, chicken, mutton, tallow and palm based shortening were heated at different temperature (120, 180 and 240 degrees C) and time (30, 60, 120 and 180 min). The spectra in the form of multivariate data were acquired using FTIR spectroscopy. Principal components analysis (PCA), k-mean cluster analysis (k-mean CA) and linear discriminant analysis (LDA) were used to compare the ability of each technique to differentiate the fats after the heating treatments. It was found that the combination of PCA with k-mean CA was able to differentiate heated fats according to its origin. LDA method was successfully used to classify 80.5 % of samples in its group. Thus, PCA, CA and LDA can be used as multivariate data analysis to differentiate the heated edible fats.

The esterification of free fatty acids with alcohols using montmorillonite (MMT) clay as heterogeneous catalyst is one of the methods to produce fatty acid alkyl ester that can be used as alternative renewable biofuels. However, the unmodified MMT gives low conversion of free fatty due to the limitation of acid sites in the clay structure. This work focuses on preparation of an environmental friendly catalyst from montmorillonite K10 (MMT K10) clay catalyst for the esterification of oleic acid with various alcohols. Esterification of oleic acid with alcohols has been carried out in the presence of metal exchanged MMT K10 (M-MMT K10; M = Fe3+ and Cu2+). The concentrations of both Fe3+ and Cu2+ precursors were varied at 1 M and 4 M. The effect of different alcohols used, molar ratio of reactants and catalyst loading on the esterification reaction was investigated. Among the exchanged clay catalysts, 4 M Fe-MMT K10 was found to be more active for the esterification of oleic acid with methanol. The maximum oleic acid conversion (ca. 68.5%) was achieved after 3 hours of reaction at the reaction temperature of 60 degrees C with molar ratio of methanol to oleic acid of 10:1 and catalyst loading of 5 wt% relative to the mass of oleic acid. The catalytic activity was found to be directly related to the amount of cation used in the modification step and Bronsted acidity of metal exchanged MMT K10 clay catalyst.

Co (II) complex (CMLA) was investigated to evaluate the rate of wound healing in rats. Animals were placed into four groups: gum acacia, Intrasite gel, 10 and 20 mg/ml of CMLA. Wounds were made on the dorsal neck area, then treated with Intrasite gel or CMLA; both of these treatments led to faster healing than with gum acacia. Histology of the wounds dressed with CMLA or Intrasite gel displayed a smaller scar width, required less time to heal and showed more collagen staining and fewer inflammatory cells in comparison to wounds dressed with the vehicle. Immunohistochemistry for Hsp70 and TGF-beta showed greater staining intensity in the treated groups compared to the vehicle group. Bax staining was less intense in treated groups compared to the vehicle group, suggesting that CMLA and Intrasite gel provoked apoptosis, responsible for the development of granulation tissue into a scar. CD31 protein analysis showed that the treated groups enhanced angiogenesis and increased vascularization compared to the control group. Furthermore, a significant increase in the levels of GPx and SOD and a decrease in MDA were also observed in the treated groups. This results suggest that CMLA is a potentially promising agent for the wounds treatment.

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.

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.

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)(6) impregnated in Teflon-AF polymer with the presence of N-2, CH4 and even weak ligand i. e. Xe and He were conducted at extremely low temperature. Photolysis of Cr(CO)(6) under N2 environment produces up to four carbonyl groups being replaced with the N2. Meanwhile, the photochemistry of Cr(CO)(6) under Xe and CH4 produce 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.

In public restaurants, food frying is conducted in the same oil and recycled for the same usage for several days. However, during household frying, the cooking oil is changed after several usage. Obviously, the conditions of the cooking oil changed depend on frying styles and the types of material fried. In this study, three different cooking oils; refined palm cooking oil purchased from local market (CO), used palm cooking oil collected from household (UCO-H) and from restaurants (UCO-R) were selected to examine the colour, acid value (AV), saponification value (SV), ester value (EV), molecular weight (MW), percentage of free fatty acid (% FFA), density, water and impurities contents. Colour was observed by naked eyes, AV and SV were analyzed based on PORIM Test Method (1995). EV was calculated according to The United States Pharmacopeia USP 29 NF 24, while MW was calculated from SV and AV results. Density was measured at 20 degrees C, percentage of water content was analyzed by heating and weighing while impurities content was studied by filtering and weighing. The results showed that as frequency of frying increased, the colour of cooking oil become darker from the CO. The AV was always depend on % FFA. The % FFA of UCO-H and UCO-R were differed by 0.35 % and 2.15 % respectively compared to CO (2.20 %). Meanwhile, the density, water content and impurities content were also increased slightly compared to CO. The SV was found increased slightly for both UCO-H (207.41 mg of KOH/g) and UCO-R (204.74 mg of KOH/g) as compared to CO (200.59 mg of KOH/g). The value of ester was remained constant for UCO-R with value 196.04 mg of KOH/g in comparison with the EV of CO which is 196.19 mg of KOH/g. While for UCO-H sample, the EV increased to 202.32 mg of KOH/g. In conclusion, according to the physicochemical characteristics, the colour became darker while AV, % FFA, density, water content and impurities content increased with frying period. However, the SV and EV were not depending on frying period but they changed according to the type of reaction occurred during frying; among the components inside the oil or between oil components with the food contents. (C) 2019 Elsevier Ltd. All rights reserved.