Abstract: Epoxidation of linseed oil with peroxyformic acid generated by the reaction of formic acid and hydrogen peroxide in the presence of phosphoric acid as the catalyst was studied, and the optimized reaction conditions were also obtained by the application of orthogonal experimental method. Impacts of raw linseed oil level and feeding methods on the epoxidation of linseed oil were also investigated in this paper. The results showed that factors affecting the epoxidation of linseed oil were in the order of the amount of phosphoric acid>hydrogen peroxide>formic acid>reaction temperature. The epoxy value of the final product could reach 8.10% under the following optimized conditions: mlinseed oil:mphosphoric acid:mhydrogen peroxide:mformic acid=1∶0.01∶1.55∶0.29, using the feeding method of dropping the mixture of phosphoric acid/hydrogen peroxide/formic acid to the reactor under 65 ℃, reaction temperature was 68 ℃ and time was 3 h. FTIR analysis showed the successfully synthesized of epoxidized linseed oil by the epoxidation reaction and thermogravimetric analysis/differential thermal analysis(TG/DTA) proved good thermal stability of the epoxidized linseed oil obtained.

Key words: linseed oil, epoxidation, plasticizer, synthesis, characterization