Recovery of polyols from flexible polyurethane foam by “split-phase” glycolysis: Glycol influence

Scrap of flexible polyurethane foams from slabstock manufacturing comprises about 10% of the total production, leading to not only an environmental problem but also an economic one. The general purpose of polyurethane chemical recycling is to recover a valuable constituent, the polyol. Among the processes suitable, glycolysis, and specially glycolysis in two phases seems to be the method that allows better quality products. In this study glycolysis of flexible polyurethane foams in “split phase” was conducted with different glycols, in order to study their activity and select a system to obtain the highest quality recovered polyol. Reaction kinetics and the products obtained were investigated. Times required to reach complete conversion, chemical properties of the polyol phase and its purity depended on the glycol employed. Diethylene glycol proved to be the most suitable glycol to obtain a high purity in the polyol phase.