They are basically fatty acids or esters of fatty acids namely, Palmitic Acid CH3(CH2)14COOH Stearic Acid C18H36O2, or CH3(CH2)16COOH Oleic Acid CH3(CH2)7CH=CH(CH2)7COOH.
All materials are made from chemicals and have a chemical composition. Doesn't matter if its steel, iron, bronze, brass or plastic. It is this chemical composition and the ratios of its chemistry...