Sustainable synthesis of Di-iso-octyl Maleate using 3-octanol extracted from Peppermint oil

Surfactants are vital in industries such as detergents, textiles, and cosmetics, and their synthesis from renewable or waste-derived feedstocks aligns with sustainability goals. This study explores the valorization of 3-octanol, a byproduct of peppermint oil extraction, into di-isooctyl maleate (DOM), a precursor to di-octyl sulphosuccinate (DOSS), a widely used surfactant. The synthesis of DOM was achieved via esterification of 3-octanol and maleic anhydride in the presence of para-toluene sulphonic acid (PTSA) as a catalyst. Reaction parameters, including catalyst concentration, reaction time, and temperature, were systematically optimized to maximize yield. The highest yield of 96.34% was obtained using 0.4 g of PTSA per 5 g of 3-octanol, with an optimal temperature of 80–85°C and a reaction time of 3 hours. Experimental data showed a decline in yield beyond this catalyst concentration and reaction duration, indicating the importance of precise parameter control. Alternate catalysts such as Amberlite and Indion 130 were tested. This study demonstrates a sustainable and scalable approach to converting waste-derived 3-octanol into value-added surfactants, providing an economically viable solution with minimal equipment and investment requirements.