Used frying oil can come in handy… to lubricate an engine. This is not a paradox, but the summary of research presented by Irene Anguillesi from the University of Pisa at the III National Conference of the SCI Division of Chemistry for Technologies and the XIV AICIng Conference, as part of the national CO-SMART project dedicated to sustainable mobility.
Her talk, titled “Synthesis and Characterization of Waste Cooking Oil-Derived Polyols for Use as Biolubricants”, outlined a virtuous journey of green chemistry and circular innovation, in which a common waste—waste cooking oil (WCO)—is transformed into a high-performance technical resource: biolubricants.
From fats to lubricants: the recipe of sustainable chemistry
The research team focused on the synthesis of polyols—chemical compounds containing hydroxyl groups—through a two-step process: epoxidation of the used oil, followed by ring opening with ethanol to produce products with high hydroxyl numbers (up to 177 mg KOH/g).
These polyols were then subjected to structural characterisation (FTIR), thermogravimetric analysis (TGA), and tests to evaluate their rheological and tribological properties. The results were highly promising: the polyols exhibited stable Newtonian behaviour across a wide temperature range (25, 40 and 100 °C), constant viscosity, and an excellent viscosity index (up to 132)—well above the 100 threshold considered optimal for lubricants.
Tribological performance—linked to friction reduction—was also favourable, with an average coefficient of friction of 0.19, making them suitable for boundary lubrication conditions.
Biolubricants: a credible alternative for industry
Today, the industrial lubricant sector is dominated by fossil-based products, often with a high environmental impact. The research conducted by Anguillesi and colleagues demonstrates that comparable (or even superior) performance can be achieved using a waste material—making the process both economically advantageous and environmentally sustainable.
This is more than a lab-scale innovation: waste oil-based biolubricants are emerging as a viable technical solution for industrial applications, opening up new opportunities in the automotive, mechanical, and agricultural sectors.
CO-SMART: where mobility meets green chemistry
Irene Anguillesi’s presentation added another piece to CO-SMART’s broader vision: transforming the mobility of the future not only through electrification or new transport models, but also by rethinking the materials and fluids that make movement possible.
From kitchens to workshops, waste cooking oil finds a second life—and proves that even the simplest waste, with the right scientific approach, can become the driving force of truly sustainable mobility.
