Application of oxazolidine in wet-white tanning

The commitment to sustainable development has been one of the main concerns of the world. In this sense, this work aims to develop a process for the application of oxazolidine in wet-white tanning and its viability for increasing the thermal stability of leather, reducing in this way the environmental impact of the tanning process. In order to achieve the higher shrinkage temperature, different parameters have been tested, such as time of reaction of the gluteraldehyde; the time of reaction and concentration of oxazolidine; the effect of synthetic and vegetable tannins at different conditions. Important conclusions were achieved, such as the direct relation between thermal stability and oxazolidine concentration, and the direct relation with the application time of tannins. The main result, a shrinkage temperature of 84.2°C, was obtained with a concentration of 6% w/w of oxazolidine and a contact time of 8 hours. Although the shrinkage temperature is high, there are still many improvements that must be done to achieve higher stability and then be exported to a pilot scale.