Effect of Poly(acrylamide-acrylic acid) on the Fire Resistance and Anti-Aging Properties of Transparent Flame-Retardant Hydrogel Applied in Fireproof Glass

Abstract

Poly(acrylamide-acrylic acid) (P(AM-co-AA)) was synthesized via the copolymerization of acrylamide and acrylic acid and well characterized by Fourier transform infrared spectroscopy. Afterward, the obtained P(AM-co-AA) was blended with flame retardants to prepare transparent flame-retardant hydrogel applied in the fireproof glass. The influence of poly(acrylamide-acrylic acid) on fire resistance and anti-aging properties of the transparent flame-retardant hydrogels were studied by assorted analysis methods. The optical transparency analysis shows that the light transmittance of the transparent flame-retardant hydrogel gradually decreases with the decreasing mass ratio of acrylamide to acrylic acid in P(AM-co-AA). Heat insulation testing shows that the heat insulation performance of fireproof glass applying the transparent flame-retardant hydrogel firstly decreases and then increases with decreasing mass ratio of acrylamide to acrylic acid in P(AM-co-AA). When the mass ratio of acrylamide to acrylic acid is 1:2, the obtained P(AM-co-AA) endows the resulting flame-retardant hydrogel applied in fireproof glass with the lowest light transmittance of 81.3% and lowest backside temperature of 131.4 °C at 60 min among the samples, which is attributed to the formation of a more dense and expanded char to prevent the heat transfer during combustion, as supported by the digital photos of char residues. The results of TG analysis indicate that P(AM-co-AA) imparts high thermal stability to the resulting hydrogels due to the hydrogen bonds between carboxyl and amide groups. The accelerated aging test shows that the transparent flame-retardant hydrogel containing P(AM-co-AA) is less affected by aging conditions. Especially, when the mass ratio of acrylamide to acrylic acid in P(AM-co-AA) is 4:1, the resulting transparent flame-retardant hydrogel shows a light transmittance of 82.9% and backside temperature of 173.1 °C at 60 min after 7 aging cycles, exhibiting the best comprehensive properties among the samples.

Fabrication and Performance of Multisensory Flexible Hydrogel toward Strain, Temperature, and Flame Sensing

“…When the test temperature rises to 350 °C, the polyacrylamide main chain depolymerizes into imide, acrylonitrile, and CO 2 , accompanied by the formation of a molten carbon layer. Compared to PAM-D hydrogel, the PAM/GO 1.4 /Ni 21.4 -D hydrogel exhibits less mass loss in the first stage, which is attributed to the greater difficulty of volatilizing physically bound water and dehydrating hydroxyl groups compared to free water . This phenomenon can be explained by the fact that the introduction of −NH 2 and GO interaction the hydrogel’s water retention properties, resulting in excellent thermal stability and carbonization efficiency …”

“…Compared to PAM-D hydrogel, the PAM/GO 1.4 /Ni 21.4 -D hydrogel exhibits less mass loss in the first stage, which is attributed to the greater difficulty of volatilizing physically bound water and dehydrating hydroxyl groups compared to free water. 35 This phenomenon can be explained by the fact that the introduction of −NH 2 and GO interaction the hydrogel's water retention properties, resulting in excellent thermal stability and carbonization efficiency. 36 Figure 7b shows a schematic diagram of the PAM/GO 1.4 /Ni 22.4 hydrogel burning under an alcohol lamp.…”

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

“…6 Wang et al have observed an enhancement in fire resistance and anti-aging property of polyacrylamide hydrogel by introducing acrylic acid and methacrylic acid, respectively. 7,8 Chen et al revealed that the addition of ammonium polyphosphate to shear stiffening gel can provide effective impact resistance and fire resistance. 9 In summary, the construction of the interpenetrating polymer network can bring high stability to hydrogels, but there are few reports of their application to fireproof glass.…”

“…Li et al found that hydrogels formed by acrylamide, acrylic acid and water glass can effectively improve their water retention and compression resistance 6 . Wang et al have observed an enhancement in fire resistance and anti‐aging property of polyacrylamide hydrogel by introducing acrylic acid and methacrylic acid, respectively 7,8 . Chen et al revealed that the addition of ammonium polyphosphate to shear stiffening gel can provide effective impact resistance and fire resistance 9 .…”

Facile Fabrication of Multifunctional Transparent Flame-Retarded Hydrogel for Fire-Resistant Glass with Excellent Transparency, Fire Resistance and Anti-Ageing Property

“…Therefore, it is crucial to enhance the fire resistance of transparent flame-retarded hydrogels via chemical modification of hydrogel network and physical adding flame retardants. Ammonium polyphosphate (APP), ammonium dihydrogen phosphate (ADP), ammonium hydrogen phosphate and other phosphorus-based flame retardants are widely used in the field of flame-retarded hydrogels to protect the hydrogel from burning [7]. Zheng et al introduced basalt fibers and ammonium polyphosphate (APP) into polyacrylamide hydrogels to improve the fire resistance properties and found that APP can effectively delay the thermal decomposition process of the hydrogel by forming an expanded char layer [8].…”