Abstract:

Two component alcoholysis agents， ethylene glycol （EG） and diethylene glycol （DEG）， were used to degrade the waste polyisocyanurate foams （PIR） to obtain polyol as the degradation product. The regenerated PIR foams were obtained through foaming the degradation product. The infrared spectrum and viscosity of the degradation product were and analyzed. The apparent density， compression strength， thermal conductivity and thermal stability of the regenerated PIR were investigated. The results indicated that the degradation of waste PIR and regeneration of PIR obtained an optimal effect at a mass ratio of mEG to mDEG of 1/2 and a NaOH catalyst amount of 1.0 g under the degradation reaction condition at 180 ºC for 1 h and then at 190 ºC for 1 h. In this case， the viscosity of the degradation product was 2 246 mPa∙s. The apparent density of regenerated PIR was 0.044 8 g/cm³， its compressive strength was 0.398 MPa， and its thermal conductivity was 0.025 W/m∙K. All performance parameters can meet a requirement of national standards.

Key words: polyisocyanurate foam, degradation, recovery, reuse, alcoholysis agent