Characterization and Determination of the Kinetics of the Interaction During the Preparation of Fat‐Liquor From Waste Fat

ABSTRACT Fat‐liquoring chemical, an emulsified formulation of alkali and fat or sulfited oil, is added slowly to processed hides during leather making, penetrating into the empty cells of the leather matrix and acting as filler. Waste tallow‐fat is used to prepare present value‐aided products through steps, namely amidation, esterification, and sulfitation. These steps are optimized in terms of feed, auxiliary, duration, and temperature. It was found that 9% tallow reacts with 35% diethanolamine and 1.2% maleic anhydride at 120°C for 3.5 h. The conversion was found to be 97.2%. Triglycerides react with diethanolamine to form amide, which, after esterification with maleic anhydride and sulfited with sodium bisulfite, yields a product. The fat‐liquor is characterized using UV, SEM, FTIR, and NMR studies. In order to achieve low foaming, better emulsion, flame retardant, and low surface tension properties, the auxiliaries were added to the intermediate product to yield sulfosuccinate fat‐liquor, an anionic emulsifier, whose surface activity was determined. The product sulfosuccinate fat‐liquor showed the desired properties for application in the leather industry due to its good biodegradability and economic feasibility.