Production of leather-like composites using chemically modified short leather fibers. I: Chemical modification by emulsion polymerization

In order to evaluate the possible use of short leather fibers to produce leather‐like composites, five kilograms of fibers (extracted from leather wastes) were modified by in situ emulsion polymerization of methyl methacrylate (MMA). This treatment was performed in order to increase the compatibility of leather fibers with several commodity polymers used in the shoe and furrier industries. The chemical modification was carried out by aqueous emulsion polymerization initiated by a redox system (potassium persulfate and sodium metabisulfite). The effects of the monomer and redox initiator content as well as the reaction temperature were evaluated. The modified short leather fibers were characterized by instrumental techniques such as Infrared Spectroscopy (IR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), X‐ray Diffraction and Scanning Electronic Microscopy (SEM). The results show that the polymer is formed on the exterior of fibers (deposited fraction) as well as in the interior (by grafting or forming interpenetrated networks). The treatment significantly improves the thermal stability of fibers. It also reduces their water adsorption capacity, as a coating of PMMA is produced over the leather surface, as microscopic analysis has revealed. The last characteristic could be an advantage in certain applications.