The Effect of Gmelina Seed Oil on the Synthesis of Alkyd Resins

The usage of edible oils for alkyd resin synthesis has lately been of great concern because they can alter the food chain. Research is on the forefront on the oils that are considerably available and do not compete with food sources. Thus, the viability of preparing alkyd resin from inedible, non-drying gmelina seed oil (GSO) was investigated. The physico-chemical properties (viscosity, iodine value, specific gravity, refractive index and acid value) of the GSO were determined and then, it was neutralized, epoxidized, hydroxylated and dehydrated. The fatty acid profiles of the raw oil were determined with GC-MS. The structure of raw GSO, chemically modified GSO and their alkyds were determined using FT-IR spectrometry. Medium GSO length modified alkyd resin was produced via a two stage alcoholysis-esterification method using glycerol, maleic and phthalic anhydride. GC-MS result confirmed that GSO is predominantly saturated, while the FT-IR result confirmed the desaturation and esterification of GSO. Using nano-ZnO pigment, a through dry time of about 8 hrs was obtained with GSO modified alkyd resin C. The alkyds C and D show excellent mechanical properties; H passed and 2H passed for scratch hardness test, good for adhesion test and passed for impact test. Further comparison revealed that Alkyds A and C showed robust resistant to varying chemical medium in comparison with standard alkyd resin.