Resin derived from Mahogany Seed Oil

Mahogany Khaya senagalensis A. juss commonly known as African mahogany belongs to the family Meliaceae, a popular medicinal plant among the Nupes and Yorubas in Nigeria. The stem bark aqueous extract is traditionally used by Yoruba and Nupe tribes to treat malaria, jaundice, oedema and headache. Khaya senegalensis seeds have been reported to contain about 67% oil content by weight. The oil is rich in oleic acid (66%) and used in West African cosmetics. In this research Mahogany Seed Oil (MSO) was obtained from the local market and employed in the preparation of the alkyd resin (oil modified ester) using the monoglyceride method. First, the oil was reacted with glycerol (alcoholysis) to form a monoglyceride which was further reacted with phthalic anhydride (polycondensation) to form the alkyd resin. The MSO and its corresponding alkyd resin were characterised by fourier transform infrared spectroscopy (FTIR). The alkyd resin was found to have antimicrobial activity against Escherichia coli, Salmonella typhi and Staphylococcus aureus as evaluated using paper disc diffusion method. The prepared alkyd resin was subsequently used to prepare surface coatings which exhibited properties that are comparable to those of commercial alkyds, as its films air-dried within few hours. Also, the films exhibited good chemical resistance in various solvent media such as brine, water and dilute acid but low resistance to alkali which could be due to alkaline hydrolysis. The surface coating also shows a very good fastness to light which suggests the potentials of Mahogany seed oil alkyd resin as binder in the preparation of surface coatings with promising antimicrobial properties.