Characterization and Investigation of Electrical Properties of Epoxidized Soybean Oil-tri Salicyl Borate Polymer

Abstract

In this study, polymerization and characterization of trisalicyl borate (TSB) with epoxidized soybean oil (ESO) was evaluated. Synthesis of TSB is involved by the reaction between boric acid and salicylic acid at the first step of the reaction. Then TSB was polymerized with ESO at 95 ℃ for 6 hours. All the compounds synthesized were characterized by FTIR and 1H NMR techniques. Characteristic bands of the boron esters appeared at 1644, 1610, 1578, 1472, 1276, 784, 757, 656, and 530 cm-1. 1H NMR technique indicated that hydrogens of the free carboxyl groups revealed at 10.8 ppm. The resultant polymers of TSB and ESO were rubbery materials. Mechanical, thermal and electrical properties of the TSB-ESO polymer was determined. They exhibit small stress at break values with high strain percentages. Thermal and mechanical characterization of the polymers were performed by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Stress-Strain tests. It was found that TSB-ESO polymer exhibited highest swelling ratio in toluene. The TSB-ESO polymer was a rubbery material that showed 0.1 MPa stress at break value with 240% elongation. Thermal properties of the synthesized polymer were evaluated with DSC and TGA methods. TSB-ESA showed one Tg at -2 ℃ and a melting peak at 92 ℃. TGA plot showed 2 segmental weight loss. As an indicator for thermal stability, 5% weight loss temperature was measured as 112 ℃. Additionally, DC analysis reveals that the resistivity and conductivity of the polymeric sample is measured as 2.375 MΩm and 0.401 μS/m respectively.