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The effect of antioxidants on the oxidation stability of oils extracted from Jatropha curcas seeds was measured by the accelerated oxidation test specified in EN 14112 using commercial Rancimat 873 equipment. To find the appropriate antioxidant for jatropha oil, fourteen different antioxidants were screened at concentrations of 500 and 1000ppm. Pyrogallol (PY) and propyl gallate (PG) significantly improved the oxidative stability of jatropha oil and PY was further studied at concentrations of 50-1000ppm. Even at concentrations as low as 50ppm, PY was found to fulfill the specifications set by the DIN 51605 norm for plant oil as biofuels. Mixtures of antioxidants were tested at concentrations varying between 100 and 1000ppm, showing a synergistic effect for the combination of PY and N,N-di-sec-butyl-p-phenylenediamine at all concentrations and ratios tested. It further was found that the quality, i.e. the history of the oil in terms of processing, age and storage conditions, strongly affects the performance of PY as the antioxidant. PY in particular improved the oxidative stability of oxidized and highly acidic oils. PY was found to be a good antioxidant for both jatropha oil and the derived biodiesel. Practical applications: Jatropha oil is one of many potential triglyceride feedstocks suitable for the production of biofuel or other consumer products. Finding the best antioxidant for this particular resource is important since the resistance to oxidative degradation depends on the chemical structure of the triglyceride. Pyrogallol was found to be the preferred antioxidant with beneficial results found for oxidized and, as a result, highly acidic oils. The results of this study are useful for companies involved in jatropha oil-derived products such as biodiesel, lubricants or other non-food applications.

This paper describes a systematic study on the synthesis of higher fatty esters of corn starch (starch laurate and starch stearate) by using the corresponding vinyl esters. The reactions were carried out in DMSO using basic catalysts (Na(2)HPO(4), K(2)CO(3), and Na-acetate). The effect of the process variables (vinyl ester to starch ratio, catalyst intake, reaction temperature and type of the catalyst) on the degree of substitution (DS) of the starch laurate and starch stearate esters was determined by performing a total of 54 experiments. The results were adequately modeled using a non-linear multivariable regression model (R(2)>= 0.96). The basicity of the catalyst and the reaction temperature have the highest impact on the product DS. The thermal and mechanical properties of some representative product samples were determined. High-DS products (DS = 2.26-2.39) are totally amorphous whereas the low-DS ones (DS = 1.45-1.75) are still partially crystalline. The thermal stability of the esterified products is higher than that of native starch. Mechanical tests show that the products have a tensile strength (stress at break) between 2.7-3.5 MPa, elongation at break of 3-26%, and modulus of elasticity of 46-113 MPa.

A series of epoxidized oils were prepared from rubber seed, soybean, jatropha, palm, and coconut oils. The epoxy content varied from 0.03 to 7.4 wt %, in accordance with the degree of unsaturation of the oils (lowest for coconut, highest for rubber seed oil). Bulk polymerization/curing of the epoxidized oils with triethylenetetramine (in the absence of a catalyst) was carried out in a batch setup (1 : 1 molar ratio of epoxide to primary amine groups, 100 degrees C, 100 rpm, 30 min) followed by casting of the mixture in a steel mold (180 degrees C, 200 bar, 21 h) and this resulted in cross-linked resins. The effect of relevant pressing conditions such as time, temperature, pressure, and molar ratio of the epoxide and primary amine groups was investigated and modeled using multivariable nonlinear regression. Good agreement between experimental data and model were obtained. The rubber seed oil-derived polymer has a T-g of 11.1 degrees C, a tensile strength of 1.72 MPa, and strain at break of 182%. These values are slightly higher than for commercial epoxidized soybean oil (T-g of 6.9 degrees C, tensile strength of 1.11 MPa, and strain at break of 145.7%). However, the comparison highlights the potential for these novel resins to be used at industrial/commercial level. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42591.