Synthesis of non-phosphorylated epoxidised corn oil as a novel green flame retardant thermoset resin

This study aimed to produce a new potential flame retardant thermoset resin from epoxidised corn oil through a one-pot method using liquid inorganic catalysed with hydrogen peroxide. Using a gas chromatography–mass selective detector, attenuated total reflectance-fourier transform infrared spectroscopy, proton nuclear magnetic resonance imaging, optical microscopy, and scanning emission microscopy, we synthesised a bio-based resin based on newly designed parameters. The flame retardant capacity was fully established using thermogravimetric analysis and a micro calorimeter. The produced epoxidised corn oil had a relative percentage conversion of oxirane of approximately 91.70%, wherein the amount of double bonds converted into epoxides was calculated. A significant reduction from 17 to 40% in peak heat rate release (pHRR) and 26–30% in total heat release was observed, confirming its flame retardant property. Thus, the potential of epoxidised corn oil was demonstrated.

Thickness Variation Effects on the Efficiency of Simulated Hybrid Cu2ZnSnS4-Based Solar Cells Using SCAPS-1D

This study presents the simulations of a hybrid Cu2ZnSnS4-based solar cell with a planar heterojunction structure in a hybrid model (n-FTO/n-ZnO/p-PSCS/p-CZTS/p-PSCS/p-HTM) using a One-Dimensional Solar cell capacitance simulator (SCAPS-1D). . The configuration "121" of the hybridizing absorber layers of the device was simulated and related with as-Copper Zinc Tin Sulphide (CZTS). The simulation used an absorber layer with a step-length thickness of 25 nm and thicknesses ranging from 100 nm to 500 nm. The bandgap diagram, I-V characteristics curve, percentage conversion efficiencies, and the quantum efficiencies of the simulated solar cells were calculated and constructed from simulated results. The percentage conversion efficiency of 22.57%, fill factor of 49.99%, open-circuit voltage of 0.80V, and short circuit current of 25.12 mAcm-2 were obtained. The obtained photon conversion efficiency shows that the hybridization of different absorber layers was achievable. It was also established that the performance efficiencies of hybrid CZTS structure in terms of optimum thickness and sandwiched Perovskite Solar cells model (FTO/ZnO/CZTS/PSCS/CZTS/HTM) has the same efficiencies for "121 configurations". On the other hand, the efficiencies of as- CZTS structures were higher than the PSCS configuration, which might be due to SCAPS-1D as it was originally designed for Thin Films Solar cells.

Implementation of a Low Power Boost Converter in-line with a Rectifier for RF Energy Harvesting Application

With the growing requirement of RF coverage, harvesting and management of the associated power along with the conversion of energy into appropriate form is essential. It makes the design of relevant rectifier systems an important aspect. Attainment of a high percentage conversion efficiency (PCE) at lower input power, may not be enough if it is not supported by a DC-DC converter. A boost converter plays a significant role for managing the harvested energy for further utilization. This paper presents a simple, low power, high frequency boost converter for specific target storages or applications. It achieves a peak efficiency of 93% at a very low input power of -12dBm with the use of only two MOSFETs and for smaller value of inductance making the design feasible. Moreover it achieves a very good transient settling time of 5.5μs

Evaluation of Shell-Derived Calcium Oxide Catalysts for the Production of Biodiesel Esters from Cooking Oils

Due to the high cost of feedstock and catalyst in biodiesel production, the viability of the biodiesel industry has been dependent on government subsidies or tax incentives. In order to reduce the cost of production, food wastes including eggshells and oyster shells have been used to prepare calcium oxide (CaO) catalysts for the transesterification reaction of biodiesel synthesis. The shells were calcined at 1000 °C for 4 hours to obtain CaO powders which were investigated as catalysts for the transesterification of waste cooking oil. The catalysts were characterized by Fourier Transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and X-ray fluorescence (XRF) spectroscopy. Reaction parameters such as methanol-to-oil molar ratio, CaO catalyst concentration, and reaction time were evaluated and optimized for the percentage conversion of cooking oil to biodiesel esters. The oyster-based CaO showed better catalytic activity when compared to the eggshell-based CaO under the same set of reaction conditions.

Evaluation of Consortium Enzyme towards Kojic Acid Synthesis

Consortium enzyme is a new approach in enzymatic esterification reaction to solve Kojic acid esters' low production. Combining a non-specific enzyme (Novozym 435) and a specific enzyme (Lipozyme RM IM) led to an improvement of enzymatic activity in the enzymatic routes. The findings proved that a significant percentage conversion of ester (29.2 %) was successfully achieved at the enzyme ratio (1:1) of Lipozyme RMIM and Novozym 435, the temperature at 50 ?C, amount of enzyme 0.12 g and 8 hours of reaction time. Moreover, the enzyme showed high stability against heat at 500C and can be used repeatedly up to the 5th cycle, as demonstrated by the high percentage conversion of kojic acid ester. This finding confirmed that consortium enzymes have significantly improved the reaction performance by promoting better catalytic efficiency due to the synergistic effect between combined enzymes.

Highly Selective pH-Dependent Ozonation of Cyclohexane over Mn/γ-Al2O3 Catalysts at Ambient Reaction Conditions

The selective oxidation of cyclohexane to a mixture of cyclohexanol and cyclohexanone (KA oil) is one of the imperative reactions in industrial processes. In this study, the catalytic performance of manganese-supported gamma alumina (Mn/γ-Al2O3) catalysts is investigated in the selective oxidation of cyclohexane at ambient conditions using ozone. The catalysts were prepared by the wet impregnation method, and their physio-chemical properties were studied by Fourier Transform Infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) spectroscopy, Scanning Electron Microscopy-Energy Dispersive X-ray spectroscopy (SEM-EDX), Transmission Electron Microscopy (TEM), Inductively Coupled Plasma (ICP) spectroscopy, and Brunauer Emmett and Teller (BET). The reaction conditions were optimised considering various parameters such as reaction time, pH, and various percentages of the manganese supported in gamma alumina. The oxidation of cyclohexane was conducted in an impinger reactor unit at pH 3, 7, and 11 for 1 h of ozonation time. The aliquots were collected after 30 min and 1 h of ozonation time and analysed with GC-MS and FT-IR spectroscopy. The 2.5% Mn/γ-Al2O3 catalyst exhibited a significantly enhanced catalytic performance at pH 3 and 7 with a percentage conversion of 9% and 15% at pH 3 and 7, respectively, after 30 min of ozonation time. However, after 1 h of ozonation time, the percentage conversions were increased to 23% and 29% at pH 3 and 7, respectively. At pH 11, 5% Mn/γ-Al2O3 exhibit high catalytic performance with a percentage conversion of 19% and 31% after 30 minutes and 1 h of ozonation time, respectively. The percentage selectivity obtained is 100% toward KA oil and/or cyclohexanone depending on pH and reaction time.

Hydrolysis of microcrystalline cellulose isolated from waste seeds of Leucaena leucocephala for glucose production

The waste seeds of Leucaena leucocephala (LLS) used in this study were unused residues obtained after oil and polysaccharides extraction. The microcrystalline cellulose (MCC) was isolated from LLS by acid treatment. MCC produced was, then, further converted to glucose by using sulphuric acid at 121 °C by varying the acid concentration and reaction time. The sugar composition was analyzed by using the phenol-sulfuric acid method and pre-column derivatization HPLC technique. The yield of glucose ranging from 70–85% could be obtained from MCC hydrolyzates, depending on the hydrolysis factors, which corresponding to around 57-75% of the percentage conversion of MCC to glucose.Cellulose isolated from LLS was, therefore, potentially suitable to be utilized in liquid biofuels and other value-added chemicals such as bioethanol, 5-hydroxymethylfurfural(HMF), and levulinic acid.

SYNTHESIS AND CHARACTERIZATION OF FATTY ACID METHYL ESTER MIXTURES DERIVED FROM ACORN KERNEL OIL

Biodiesel fuels are produced via transesterification of a triacylglycerol (TAG, e.g. vegetable oil, waste cooking oil, or animal fats) with a short-chain alkyl alcohol in the presence of a suitable catalyst. Alternative TAG sources, ones not derived from plants used as human food sources, have been of particular recent interest. In this work, the oil extracted from the endosperm of acorns, acorn kernel oil (AKO), was used as an alternative TAG source for the synthesis of biodiesel fuels. Acorns were collected from various species of oak trees (Quercus spp.) in the city of Nacogdoches, Texas. AKO was extracted from the acorn endosperm. The AKO was then subjected to acid-catalyzed and base-catalyzed transesterification with methanol and ethanol to produce acorn kernel oil methyl esters (AKOME) and acorn kernel oil ethyl esters (AKOEE) respectively. Concentrated H2SO4 was used as the acid catalyst and K2CO3 was used as the base catalyst. The effect of using a room temperature ionic liquid on percentage conversion for base-catalyzed transesterification was also investigated. Product mixtures were characterized using 1H-NMR spectroscopy. The NMR data were used to confirm the presence of transesterified products as well as to quantify the percentage conversion for the reaction. Percent conversion results ranged from 96 to 98% for AKOME products and 96 to 97% for AKOEE products.

Liquid-assisted grinding and ion pairing regulates percentage conversion and diastereoselectivity of the Wittig reaction under mechanochemical conditions

Mechanochemistry is maturing as a discipline and continuing to grow, so it is important to continue understanding the rules governing the system. In a mechanochemical reaction, the reactants are added into a vessel along with one or more grinding balls and the vessel is shaken at high speeds to facilitate a chemical reaction. The dielectric constant of the solvent used in liquid-assisted grinding (LAG) and properly chosen counter-ion pairing increases the percentage conversion of stilbenes in a mechanochemical Wittig reaction. Utilizing stepwise addition/evaporation of ethanol in liquid-assisted grinding also allows for the tuning of the diastereoselectivity in the Wittig reaction.

A STATISTICAL APPROACH FOR OPTIMIZING THE HIGH YIELD GREEN PRODUCTION OF THE FLAVOR ESTER BUTYL BUTYRATE

Being the prevailing approach for producing esters such as butyl butyrate, the use of chemical route has been linked to numerous disadvantages. Hence, a green alternative method for higher yield production of butyl butyrate by esterification reaction utilizing Novozyme 435 as biocatalysts in a solvent-less system may prove useful. Such approach can be further improved by optimizing the relevant reaction parameters using the Response Surface Methodology by the Box-Benkhen Design attempted in this present study. The reaction parameters evaluated were: substrate molar ratio, time and temperature, and the response of each parameter was measured as percentage conversion yield. Using the Design Expert 7.1.6 optimization functions, the two sets of optimum conditions selected viz. [i] molar ratio butyric acid:butanol 1:3.93, 9.93 h at 56.09°C and [ii] molar ratio butyric acid:butanol 1:3.35, 9.79 h at 53.90°C had afforded the highest yield of butyl butyrate i.e. 99.62% and 99.55%, respectively. The ester product obtained from the reaction were confirmed as butyl butyrate by FTIR and GC. Therefore, the results substantiated the applicability of the RSM prediction technique as well as efficacy of Novozyme 435 as biocatalysts in the high yield solvent-less synthesis of butyl butyrate, adhering to the philosophy of Green Chemistry.