This paper studies the mechanical properties of bio-epoxy resins blended with synthetic epoxy resins (epoxamite). The bio-epoxy resins were derived from Jatropha methyl esters through epoxidation method. They were formulated with epoxamite and hardener at different compositions and then cured at different temperature and time settings. The cured blends were subjected to tensile and flexural tests using Instron machine. Tensile and flexural strength of the mixtures were compared with the 100% epoxamite in order to evaluate the suitability of bio-epoxy resins as an alternative to synthetic epoxy resins with respect to mechanical properties. Tensile strength of 100% epoxamite is 38.32 MPa and flexural strength is 63.32 MPa. The mixtures of bio-resins and epoxamite demonstrated very low mechanical strengths compared to the 100% epoxamite. Therefore, they are not suitable to be used as an alternative to synthetic epoxy resins in industrial applications. However, they may find other usage due to high reactivity of the bio-epoxy resins.

Epoxidized (EHO) and acrylated (AEHO) bio-resins from hemp oil were synthesized, and their interpenetrating networks (IPNs) were investigated in reinforced bio-composites with natural jute fibres and glass fibres. The mechanical properties (tensile, flexural, Charpy impact, and inter-laminar shear) and viscoelastic properties (glass transition temperature, storage modulus, and crosslink density) of the bio-resins and their hybrid IPNs EHO/AEHO system were investigated as a function of the level of bio-resin hybridization. The hybrid bio-resins exhibited interpenetrating network (IPN) behaviour. Composites prepared with the synthetic vinyl ester (VE) and epoxy resins showed superior mechanical and viscoelastic properties compared with their bio-resins and IPNs-based counterparts. With glass fibre (GF) reinforcement, increases in the EHO content of the IPNs resulted in increased stiffness of the composites, while the strength, interlaminar shear strength (ILSS), and impact resistance decreased. However, in the jute fibre reinforced bio-composites, increases in AEHO content generated increased tensile modulus, ILSS, and mechanical strength of the bio-materials. Crosslink density and glass transition temperature (Tg) were also higher for the synthetic resins than for the bioresins. Increased AEHO content of the IPNs resulted in improved viscoelastic properties.

Plant oils and their derivatives have been vigorously exploited as alternatives for synthesis of epoxides due to depletion of petroleum resources. In this study, crude jatropha oil (CJO) was subjected to a transesterification process to form jatropha methyl esters (JME) using peroxyacetic acid generated in situ from hydrogen peroxide and acetic acid via an acidic ion exchange resin (AIER). The effect of temperature, molar ratio of hydrogen peroxide to unsaturation, molar ratio of acetic acid to unsaturation, and catalyst loading were investigated. This study revealed that the maximum 89.9% relative conversion to oxirane rings was achieved after 6 h with the optimal reaction conditions of temperature at 70 ˚C, the molar ratio of hydrogen peroxide to unsaturation of 1.5 mol, the molar ratio of acetic acid to unsaturation of 0.5 mol, and catalyst loading of 16%. Fourier Transform Infrared (FTIR) spectra of the epoxidized jatropha methyl esters (EJME) showed oxirane peaks (doublet) at 825 and 843 cm-1. 1 H NMR confirmed the diepoxide group at 2.85 ppm and 2.98 ppm, while the diepoxide signals of 1 C NMR were present at 56.88-57.06 ppm. Production of bio-epoxides from Jatropha methyl esters hence looks promising with favorable physicochemical properties, availability, and versatility.

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The objective of this study was to optimize the epoxidation of fatty acid methyl esters (FAME) derived from Jatropha oil. This experiment was carried out with peracetic acid generated in situ by using hydrogen peroxide and acetic acid. A response surface methodology (RSM) central composite design (CCD) was used, with one response variable, the percentage (%) of epoxidation yield. The factors evaluated were temperature (50-80°C), the molar ratio of hydrogen peroxide (HP) to unsaturation (1.1-2 mol), the molar ratio of acetic acid (AA) to unsaturation (0.5-0.8 mol), and time (2-7 hours). The optimum percentage of epoxidation yield (90.98%) was at the condition of 65°C reaction temperature, HP to unsaturation molar ratio of 2.19, AA to unsaturation molar ratio of 0.65 for 6 hours. The formation of epoxides product (oxirane) was confirmed using Fourier transform infrared spectroscopy oxirane peaks (doublet) at 825 and 843 cm-1. The result showed good agreement with the predicted values from the RSM model.