Acrylamide is mainly used in fire-resistant glass to form a polyacrylamide hydrogel interlayer, which plays a central fireproof role. Under high temperatures, this interlayer absorbs heat through evaporation and expands to form an insulating ｃｈａｒ layer, effectively blocking heat transfer and maintaining the structural integrity of the glass. 

Detailed Mechanism 

Polymerization to Form Hydrogel 

Acrylamide monomers polymerize with crosslinking agents (such as N,N'-methylenebisacrylamide) in water to form a transparent three-dimensional network hydrogel, securely bonding multiple glass layers. 

Fire Response Process 

Heat Absorption and Cooling: The hydrogel contains a large amount of bound water, which evaporates upon heating and absorbs a significant amount of heat (latent heat of vaporization about 2260 kJ/kg), delaying the rise in glass temperature. 

Expansion and Foaming: As the temperature continues to rise, the polymer decomposes to produce non-combustible gases (such as nitrogen and carbon dioxide), causing the interlayer to expand dozens of times and form a dense, porous foam ｃｈａｒ layer. 

Thermal Insulation Barrier: The ｃｈａｒ layer has a very low thermal conductivity, physically blocking flame heat transfer to the back face of the glass, ensuring that its temperature remains below the 140°C safety limit for an extended time. 

Structural Protection Function 

Even if the fire-exposed glass breaks, the expanded gel can still adhere to the fragments, preventing the formation of penetrating holes and ensuring the fire-resistant integrity. 

Current Applications and Challenges 

Mainstream Process: Currently, most domestic composite fire-resistant glass uses acrylamide-based grouting processes and is widely applied in indoor settings such as fire doors and fire windows. 

Performance Limitations: This type of glass has poor weather resistance, with potential yellowing and loss of transparency over long-term use, and residual monomers pose environmental and health risks. 

Technological Upgrades: New environmentally friendly alternative materials are under development, aiming to eliminate toxicity and improve durability.