Characterization of Alkyd Resins Prepared from Okra Seeds Oil with Two Polybasic Acids

Abstract

The iodine values of Clemson spineless, Ex-samaru and NHAE-74 have been reported to be within the range of semi-drying oils. Hence, the oils can be used as raw materials in coating industries. This study aimed to prepare alkyd resins from the oils of Clemson spineless, Ex-samaru and NHAE-74 using two polybasic acids (phthalic and maleic anhydride) with varying concentrations of maleic acids. The physical performance, chemical resistance, solubility and viscosity of the alkyd resins were determined. The functional groups of the alkyd resin were also determined through Fourier Transform Infrared (FTIR) Spectroscopy. One-way ANOVA was used to test the significance level of drying time and solubility in different solvents. The adhesion, abrasion, and chemical resistance tests of the alkyd resin were also evaluated. There was no significant difference (p>0.05) in the drying time for all the alkyd resins synthesized. The alkyd resins were resistant to distilled water and 5% NaCl(aq) but were fairly affected by 0.1 mol dm- 3 H2SO4 (indicated by colour change) and dissolved completely by 0.1 mol dm-3 NaOH(aq). The alkyd resins were more soluble in polar solvents (acetone, ethanol and methanol) than non-polar (benzene and xylene) organic solvents and show excellent resistance to the adhesion and abrasion tests. Analysis of all the alkyd resins showed good performance characteristics, good resistance to distilled water and 5 % sodium chloride solution and fair resistance to the attack by sulphuric acid. The viscosity of the alkyd resins is proportional to the concentration of maleic anhydride. Analysis of all the alkyd resins showed good performance characteristics, good resistance to distilled water and 5% sodium chloride solution, fair resistance to the attack of sulphuric acid, all the alkyds show more solubility in protic (acetone, methanol and ethanol) solvents than aprotic (benzene and xylene) solvents. It is recommended that further research should be carried out with a view of recommending the best formulations of paints and varnishes with the produced alkyd resins with the view of finding out the possibility of reducing the importation of alkyd resins in paints industries in Nigeria.