Preparation of polyethylene glycol/polyacrylamide interpenetrating network hydrogel for simultaneously enhancing the fire protection and aging resistance of fireproof glass

To enhance the flame retardancy and aging resistance of grouting fireproof glass, different molecular weights of polyethylene glycol (PEG) were mixed with acrylamide (AM) to construct interpenetrating network hydrogels, then the obtained hydrogels were mixed with flame retardants to prepare a series of transparent flame-retarded hydrogels applied in the fireproof glass. The effects of PAM/PEG hydrogel with varying PEG molecular weight on the optical transparency, heat insulation and aging resistance of fireproof glass were investigated. Optical transparency analysis shows that the light transmittance of grouting fireproof glass decreases with the increase of PEG molecular weight in the PAM/PEG interpenetrating network. Fire tests show that PAM/PEG hydrogel significantly enhances the heat insulation and aging resistance of the grouting fireproof glass compared to the single PAM network hydrogel. The flame-retarded and anti-aging effects of PAM/PEG hydrogel in the fireproof glass varies with the PEG molecular weight, and the order is PAM/PEG2000 > PAM/PEG1500 > PAM/PEG1000 > PAM/PEG800. Accelerated aging test shows that PAM/PEG interpenetrating network hydrogel is less affected by aging conditions and exerts durable heat insulation and transmittance. Especially, the backside temperature of 3600 s and transmittance of PAM/PEG2000 system after 264 h aging test only changed 38.3°C and 1.3%, respectively, compared to the unaged PAM/PEG2000 system.