Open Access Open Access  Restricted Access Subscription or Fee Access

Studies on the Synthesis and Characterization of Epoxidized Soybean Oil



Traditionally, polymers are synthesized from petrochemical by-products. The greenhouse gas emissions from petroleum based polymers make them unattractive options as there has been an increase in climate changes and adverse weather conditions. Additionally, they are non-degradable, creating issues when used as landfills. For these reasons and more, there is an urgent need to find an alternative source of polymeric materials. Hence, this research focuses on synthesizing a completely bio-based polymer using soybean oil to achieve a high bio-content. Determining an optimum stoichiometric ratio for high oxirane oxygen content is investigated taking into consideration the effect of temperature, reaction time, and concentration of hydrogen peroxide. These parameters are monitored to achieve the highest oxirane oxygen content. Determination of the epoxide groups was done through manual titration process using ASTM D1652-11. The highest percent oxirane oxygen content of 2.86 and 2.58% was achieved when using 1 mole of hydrogen peroxide for a reaction time of 4 hours at temperatures of 50 and 60 ºC. Fourier transform infrared [FTIR) spectroscopy verified presence of low epoxide groups as determined by ASTM D1652-11 which revealed possible side reactions indicated by the disappearance of the epoxide groups. Rheological characterization plotting the viscosity versus shear rate indicated a pseudoplastic behavior at initial shear rates, but Newtonian, shear thickening, and shear thinning properties beyond 75 s-1. It is concluded that time, temperature, and variation in the concentration of hydrogen peroxide affect the epoxidation process while optimum conditions are suggested to require longer reaction times using 1 mole of hydrogen peroxide at temperatures between 50 and 60 ºC.

Full Text: