Synthesis of Polyurethanes with Low Volatile Organic Compounds Content for Upholstery and Automotive Articles

The manufacture of upholstery and automotive articles is linked to the release of Volatile Organic Compounds (hereinafter VOCs) during their manufacture, which have short and long-term effects on the health of users and the environment. In the leather sector, around 40 kg of VOCs are generated per 1000 kg of raw skin. This research work has focused on the synthesis of new and more sustainable urethane-based polymers that, in turn, allow the quality requirements of the finish to be met, which vary depending on the leather article manufactured. The main objective of the study is to minimize the content of VOCs in the different aliphatic polyurethanes synthesized in a pilot-scale reactor, making small modifications to the synthesis formulations. The synthesis route developed is based on the preparation of polymers of ionomeric polyurethanes and their subsequent dispersion in water. In the synthesis processes developed, the content of coalescing solvents and neutralizing agents, which directly contribute to the concentration of VOCs of the urethane polymers, is eliminated and / or minimized as much as possible. The new urethane-based polymers obtained have been analyzed according to the parameters of pH, viscosity, density and percentage of solids in the resin. Likewise, organoleptic tests (color, transparency, hardness, touch and tacking) and physical tests (tensile strength, water absorption, hardness and color change at 100°C for 24 hours) have been carried out on the film corresponding to each synthesized polyurethane resin. These products will be introduced in finishing formulations designed to obtain high-performance upholstery and automotive leather with minimal impact in terms of VOC content at the pilot level. Tests of fastness and physical resistance have been carried out to evaluate the performance of these leathers.