LCA-aided chemical recycling of textile waste for polyurethane foams production

The aim of this work is to study the chemical recycling of PET and PET/Spandex textile waste via glycolysis for the production of recycled polyols suitable for rigid polyurethane foam formulations. Glycolysis reactions were initially performed on pure PET textile waste, varying reaction temperature, PET/glycol mass ratio and catalyst type in order to optimize depolymerization conditions. Based on the obtained results, diethylene glycol (DEG) was selected as glycolysis agent and titanium(IV) butoxide (TiButO₄) as catalyst. The glycolysis of PET/Spandex textile waste was then investigated to assess the effect of spandex content on the process. Textile blends containing 5%, 20% and 40 wt% of spandex were treated at two different reaction temperatures, and the influence of elastomer content on reaction efficiency and polyol properties was evaluated. Finally, under the optimized conditions (220 °C, waste/glycol mass ratio 60/40 wt%, reaction time 4 h), glycolysis was carried out on textile waste containing 10 wt% of spandex. The recycled polyols obtained from PET and PET/Spandex glycolysis were used in the production of rigid polyurethane foams at different recycled polyol contents. These foams were characterized in terms of mechanical properties and thermal conductivity. The results demonstrated that the recycled foams exhibited optimal compressive strength and successfully met the thermal insulation performance targets with respect to the virgin foam. Finally, a life cycle assessment (LCA) is planned to evaluate the environmental impact of the proposed recycling process.