Effect of different catalysts on recovery and reuse of waste polyurethane rigid foam

The sharp increase of waste polyurethane rigid foam has caused great harm to the natural environment. Ethylene glycol (EG) and propylene glycol (PG) was the alcoholysis agents, and KOH and Zn 3 [Co(CN) 6 ] 2 (DMC) were used as catalysts for alcoholysis of waste polyurethane rigid foam. Regenerated polyols were prepared. The effects of different catalysts on the infrared, viscosity and hydroxyl content of alcoholysis products were discussed. Regenerated polyurethane rigid foam was prepared from alcoholysis products and analyzed by compression strength, thermal conductivity, water absorption, scanning and thermogravimetry. The effects of different catalysts on the recycling of waste polyurethane rigid foam were studied. The experimental results show that DMC catalyst is more effective than KOH catalyst under the same conditions.The alcoholysis product of DMC system has lower viscosity and higher hydroxyl content, which is more suitable for the preparation of regenerated polyurethane rigid foam., The compressive strength of the prepared regenerated polyurethane rigid foam is 254 Kpa, and the thermal conductivity is 0.0213 W m −1 ·K −1 when the amount of DMC added is 0.04%. Meanwhile, the regenerated polyurethane rigid foam has good hydrophobicity, excellent heat preservation performance, complete cell morphology and good thermal stability. It can replace the traditional polyols to prepare the regenerated polyurethane material which meets the national standard ‘rigid polyurethane foam for building insulation’ (GB/ T21558-2005).