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 .

Recycling of polyurethane wastes using different carboxylic acids via acidolysis to produce wood adhesives

“…In fact, Ghaderian et al 27 who recycled poly(ethylene terephthalate) (PET) wastes via glycolysis to be used in the production of PUF reported a reduction of the viscosity of the RP as a result of the higher extend of depolymerization. Similarly, Santos and Carone 28 who used different catalysts in the chemical recycling of wastes from flexible PUF, associated higher extend of depolymerization with the lower viscosity RP. Likewise, Luo and Li 29 who used depolymerized PET wastes via glycolysis in the synthesis of PUF, reported that the lower viscosity of RP was most likely due to the presence of lower molecular weight species.…”

The use of lignin as cross-linker for polyurethane foam for potential application in adsorbing materials

“…Polyurethane foams can be applied in many areas, including as sponges in furniture manufacturing, wastewater treatment, packaging, sound absorbing materials, adhesives, etc. (dos Santos et al 2013;Huo et al 2012;Kumari et al 2016).…”

Organocatalysis for depolymerisation

“…More recently, the efficiency of DEA and EA to degrade PU flexible foams was compared with that displayed by metal catalysts, such as acetate metallic salts, tin oxides, or tin laurates. 60 At 200°C, even though alkanolamines significantly enhanced the depolymerisation rate compared to the control reaction performed without adding catalyst, the highest efficiency was still obtained for a metallic catalyst, namely zinc acetate. Notably, DEA showed the same performance as barium acetate, while EA performed similarly to potassium salt.…”