Rice bran oil biorefining: functionalization with acrylate

Abstract

Objective: To obtain acrylated refined rice bran oil (RBO) using a combined functionalization: first,epoxidation with H2O2/Novozym 435 lipase, followed by acrylate group insertion.Design/Methodology/Approach: After being epoxidized with H2O2/Novozym 435, the refined rice branoil was acrylated via epoxy ring-opening, using triethanolamine as catalyst and 4-methoxyphenol as inhibitor.The experimental conditions of temperature (T=100 and 110 °C) and reaction time (t=3 and 4 hours), as wellas the ratio of g eRBO (epoxidized oil) to g acrylic acid (1.5 and 2.0) were considered for the functionalization.The functionalizations were monitored using iodine value (IV), saponification value (SV), and oxirane oxygencontent (OOC), Fourier transform infrared (FTIR), and nuclear magnetic resonance (1H NMR), which allowedthe estimation of the %Acrylation.Results: The 1H NMR studies indicate that the acrylation of rice bran oil is efficient, which is confirmed withthe evolution of IV, SV, and OOC. Using the OOC, the best acrylation condition was identified at T=110°C, t=3 hours, and ratio of g eRBO to g acrylic acid=1.5, obtaining a %Acrylation of 85.89% via 1H NMR.Study Limitations/Implications: Partially acrylated rice bran oil may become an intermediate in thebiorefining of this oil and be used in the synthesis of crosslinked polymers.Findings/Conclusions: Refined rice bran oil was efficiently acrylated using two consecutive steps: it wasinitially epoxidized with H2O2/Novozym 435, followed by functionalization with acrylate group.