Synthesis and Chemical Characterization of Alkyd Resins Using Maleic and Phthalic Anhydrides and Seed oil of Luffa aegyptiaca

Abstract

The study aimed to provide sustainable alternatives to reduce industries’ over-reliance on edible vegetable oil for alkyd resin preparation as applicable in paint production. Alkyd resins were synthesized and characterized from sponge (Luffa aegyptiaca) seed oil. Condensation polymerization of monoglyceride with phthalic and maleic anhydride was carried out, and physico-chemical parameters such as drying time, total solids, viscosity, and chemical resistance were investigated following standard procedures. UV–visible, FT-IR, 1H, and 13C NMR spectroscopies were used to characterize the prepared alkyd resins. Sponge seed oil alkyd resins prepared with maleic anhydride (SPOMA) had a higher percentage yield (77.56%) than sponge seed oil prepared using phthalic anhydride (SPOPA) with 64.44%. The two alkyd resins showed a better drying time of 40 – 50 min than their commercial counterparts (70 min). This was attributed to the high degree of unsaturation of the seed oil due to the considerable proportion of linoleic acid in the seed oil. The alkyd resins were largely stable in 0.1 M HCl, 5% NaCl, and 0.1 M KOH, which caused the alkyd resins to whiten and shrink. The resins were generally soluble in xylene, kerosene, and petroleum ether. The nature of the alkyd resin can be described as nonpolar. This observation was consistent with the literature report. This study concluded that quality or industrial-grade alkyd resins could be prepared from sponge seed oil and thereby serve as a cheap and viable replacement for edible oils used in industries.