Flame-resistant and thermally-insulating aerogels with a double-network structure via benzoxazine/melamine composite precusors

Polybenzoxazine/Melamine (PBa/MS) double network aerogels were prepared using melamine foam (MS) as the backbone and bisphenol A-type benzoxazine (Ba) as the maxtrix. The effect of Ba concentration in the sol-gel on the performance of the double network aerogel was investigated. During the combustion, the PBa/MS composite aerogel exhibited self-extinguishing performance. Compared with PBa-18%, the contact angle of PBa-18%/MS composite aerogel was 18 degrees higher, and the heat release peak (PHRR) and total smoke production (TSP) of the composite aerogel decreased by 7% and 39%, respectively. These values indicate that MS can significantly reduce the release of heat and smoke from the PBa aerogel, thus improving its flame retardancy. In addition, the composite aerogel formed a denser , more complete carbon layer during combustion, which blocks both heat and mass transfer. Thus, the resulting PBa/MS dual-network composite aerogels obtained in the current work are expected to meet the demands for flame-retardant, hydrophobic thermal insulation materials in many fields.