GIS Park

Plasticizers are mainly ortho-phenyl compounds, but these products are normally poisonous and have potential to cause cancer. Limitations on the density of DOP and DOA, etc, have been set by European Union Food Security Agency (EFSA). So preparation of plasticizers with characteristics of non-toxicity and environmental-protection has become the research emphases. As a good plasticizer with properties of high efficiency, non-toxicity, environmental-protection and excellent thermal stability, photostability, low flexility and very low volatility, etc, epoxidized soybean oil, made by oxidizing soybean oil with peroxides, has been extensively used, especially as addition agent in packaging materials of food, medicine, toys for children, etc. However, epoxidized soybean oil made in China still has defects, such as low epoxide number and dark color, etc., which have become an obstacle to use widely. Therefore, studies on synthesis and application of high-quality epoxidized soybean oil had been done in this paper.Several sorts of vegetable oils had been analyzed by using chromatogram and chemical test methods. Based on the oxidation mechanism of unsaturated fatty oil, epoxidized vegetable oils are mainly produced by reaction between -c=c- double bonds of fatty acid and oxidizing agent. After reacting, according to the epoxide number, iodine value, acid number and color of the reaction products, it could judge which kind of vegetable oil was most suitable for preparation of epoxidized vegetable oils. Experimental results showed that soybean oil with iodine value range from 128gI/100g to 132gI/100g could be used as the main raw material for synthesizing high-quality epoxidized vegetable oils, and the color of products is relatively light, the epoxide number could be up to 6.0%. So, the first grade product of soybean oil was finally selected as raw vegetable oil in the paper.In this paper, the formulations and preparing process of epoxidized soybean oil were detail studied. The effects of the main parameters, including reaction temperature, reaction time, adding speed of hydrogen peroxide, soaking time, holding temperature and dosage of methanoic acid and hydrogen peroxide, etc., on the epoxide number and iodine value of the final products were discussed, and the optimum conditions for preparing epoxidized soybean oils were obtained. It was suggested that this economical and environmental-friendly method preparing epoxidized soybean oils would has a wide application prospect.Studies on epoxidation catalyst were carried out in this paper. The usual catalysts included concentrated sulfuric acid, organic acid, strong-acid cationic exchange resin and aluminum sulphate, etc. Experimental results showed that, adopting concentrated sulfuric acid as catalyst, the post treatment of epoxidized soybean oil products was relatively complicated and environment pollution was heavy; adopting strong-acid cationic exchange resin as catalyst, both costs of catalyst and reaction temperature were high, and the latter accelerated the generation of secondary reaction; adopting aluminum sulphate as catalyst, the synthetic reaction time was relatively long and the color of product was rather dark. However, when hydrogen peroxide was used as catalyst, not only the costs of catalyst could be saved, but environmental pollution could be reduced.Based on decolorization theory, the caustic washing method was adopted to decolorize the epoxidized soybean oil with high epoxide number and low iodine value, and the color grade of the treated products could be less than number 200 (Pt-Co method). Finally, the epoxidized soybean oil was applied as plasticizer for preparation of PVC (Polyvinyl chloride), and the results showed that the performances of PVC samples plasticized with epoxidized soybean oil, such as thermal stability and tensile-strength, became better.In summary, the optimized synthetic conditions of epoxidized soybean oil were obtained by experimental study in this paper, and epoxidized soybean oil with high-quality was prepared. The typical properties of the products included that epoxide number was more than 6.3%, iodine value was less than 5.0gI/100g, acid number was less than 0.5mgKOH/g, and the color grade of the treated products was less than number 200 (Pt-Co method).