Synthesis and characterization of novel castor oil-based polyol for potential applications in coatings

Abstract

In this study, three sorts of polyols were successfully synthesized from castor oil using a Dean-Stark quick, eco-friendly and high-efficiency method. For this purpose, castor oil was epoxidized in the presence of two types of catalysts including γ-alumina and formic acid, named as ECOAl and ECOF, respectively. Epoxidized castor oils were then characterized by use of hydrogen nuclear magnetic resonance (H-NMR) and oxirane oxygen content analysis. The relative percentages of conversion double bond to oxirane were obtained 96% and 74% for ECOAl and ECOF, respectively. Ring opening reaction of ECOAl was performed by two types of saponified castor oil as well as castor oil in a system equipped with Dean–Stark apparatus. The synthesized polyols were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), viscometer and OH number evaluation. The material obtained in this research is a candidate to be intended in synthesis of polyurethane for coating applications.