<p>The chemical modification of Jatropha oil (JO) through sulfonation presents significant potential for application as a fatliquoring agent in leather processing. Fatliquoring is one of the key steps in leather treatment that enhances properties such as softness, flexibility, and water resistance. This study explores the sulfonation process and the physicochemical and thermal properties of sulfonated Jatropha oil (SJO). The sulfonation introduces sulfonic acid groups into Jatropha oil, enhancing its emulsifying properties and compatibility with collagen fibers in leather. Differential scanning calorimetry (DSC) was used to evaluate the oil’s thermal stability and performance across a range of temperatures. The results showed that SJO exhibits superior thermal stability, making it well suited for the demanding conditions of leather processing. Comprehensive analysis of the physicochemical properties, including electrical conductivity, viscosity, particle size, zeta potential, and surface morphology (examined through scanning electron microscopy, SEM), confirmed the oil’s enhanced functional characteristics. These evaluations revealed improved stability, penetration, and performance, establishing SJO as an effective and sustainable fatliquoring agent. This research highlights the potential of Jatropha oil as an eco-friendly alternative in leather manufacturing, reducing reliance on synthetic materials while ensuring high-quality leather production. The findings advocate for the broader integration of plant-based solutions in industrial processes, promoting sustainable practices without compromising performance.</p> Graphical abstract <p></p>