Application Of Epoxidized Castor Oil In Polyurethane Industry

In this paper, using renewable castor oil as the main raw material, H3PO4 as catalyst and H2O2 (30%, mass fraction) as oxidation agent, epoxidized castor oil was first prepared without solvent. The synthesis conditions were optimized using orthogonal experiment, the optimized reaction conditions were as follows: n(H2O2):n(double bonds of castor oil)= 1.4:1, n(formic acid):n(double bonds of castor oil)= 0.5:1, the amount of H3PO4(catalyst) was 0.3% and reaction time was 6h. Under these optimized conditons, the epoxy value of the final product was 3.23%. FT-IR and TLC were employed to characterize the production.The paper also studied the synthesis of epoxidized castor oil, which was prepared without carboxylic acid by using CH2Cl2 as solvent, [(CH3)3NC16H33]3[PO4(WO3)4] as phase transfer catalyst and H2O2 (30%, mass fraction) as oxidation agent. The synthesis conditions were optimized using orthogonal experiment, the optimized reaction conditions were as follows:n(H2O2):n(double bonds of castor oil)= 1.2: 1, m(CH2Cl2):m(castor oil)= 2.5:1, reaction temperature was 50℃and reaction time was 5h. Under these optimized conditions, the epoxy value of the epoxidized castor oil could reach 4.37%.Moreover, the paper also studied the preparation of modified waterborne polyurethane and rigid polyurethane foam, which were using epoxidized castor oil. With the increase of the amount of epoxidized castor oil, both particle size and Zeta potential of modified waterborne polyurethane emulsion showed the trend of decreased and then increased, the water resistance, acid resistance and alkali resistance of the film increased, mechanical properties and thermal stability was enhanced. Through FTIR, it showed that there was a structure of oxazolidinone ring in the rigid polyurethane foam which was modified by epoxidized castor oil. And through TG, it showed that epoxidized castor oil-based rigid polyurethane foam had better thermal stability, which confirmed that the oxazolidinone ring could improve the thermal stability of the rigid polyurethane foam.