Optimization of the hydroxylation reaction of epoxidised rice-bran oil using a response surface methodology

Abstract

Polymeric materials, such as polyurethanes (PUs) are traditionally derived from petrochemical polyols but as oil reserves are depleting and prices continue to rise, the development of alternatives is becoming necessary. Vegetable oil-based polymers are gaining popularity due to some attractive properties (e.g. viscosities) related to the specific structure of oils, as well as addressing previous concerns about the environment and sustainability. Epoxidized rice bran oil (ERBO) can be used as potential feedstock for polyol production. It is derived by expoxidation of native RBO. During the hydroxylation reaction, epoxy groups in the epoxidized oil are converted to hydroxyl groups. This work determined the optimal conditions for the hydroxylation reaction using a response surface methodology. The goal was to maximize the hydroxyl value of the resulting polyol. Response surface methodology (RSM) provides an efficient experimental strategy to study the influence of imposed variables discover a final optimum. Furthermore, RSM has additional benefits as it allows determination of interaction effects between variables and saves times as a reduced number of experiments are required. The optimal conditions for hydroxylation reaction of the ERBO were a reaction time of 125.5 min at temperature of 49°C.