Physical Properties of Polyurethane Sheets Prepared with Synthesized Soybean Oil Polyol

The development of polyurethane (PU) using natural materials is attracting much attention. Therefore, in this study, soybean oil polyol (SOP) was synthesized using epoxidized soybean oil (ESO), and the formation of OH groups in SOP was confirmed by Fourier transform infrared (FTIR). Hexamethylene diisocyanate (HMDI) was used in an equivalent ratio, and polyurethane sheets were prepared at various weight ratios of SOP and castor oil (CO). The tensile test data for the PU sheets measured by universal testing machine showed that the tensile modulus did not change significantly but the tensile strength and elongation at break increased with increasing the SOP content. The thermogravimetry data showed that as the SOP content increased, the thermal decomposition onset temperature of the PU sheet decreased due to the increase in urethane bonds per unit volume. The synthesized SOP can be used for manufacturing eco-friendly PU products.