Using different catalysts in the chemical recycling of waste from flexible polyurethane foams

Abstract

Due to their versatility, polyurethane (PU) foams have many different applications, such as sponges, filling materials in furniture, automotive seats and clothes, among others. It is also one of the main refrigerator components serving as a heat insulating material. As PUs find different application niches, they must be largely produced and, consequently, lots of waste are generated. In this work we intend to contribute to the recycle of this waste. The recovery of polyol from flexible polyurethane foams was carried out using the glycolysis process and testing different catalysts. Grounded polyurethane and a solvent, diethyleneglycol (DEG), were kept at 200 °C and under nitrogen atmosphere during three hours in the presence of a catalyst. All catalysts tested promoted the polyol mixture formation, with Zinc acetate producing the best depolymerization rate. The catalysts efficiency for the depolymerization reaction follows the order: DBTDL< BTO< HBTO< DEA ≈ Ba(Ac)2< MEA ≈ KAc< Zn(Ac)2.