Enhanced Thermal Insulation and Flame-Retardant Properties of Polyvinyl Alcohol-Based Aerogels Composited with Ammonium Polyphosphate and Chitosan

Polyvinyl alcohol- (PVA-) based aerogels have attracted widespread attention owing to their low cost, eco-friendliness, and density. However, the applications of PVA-based are limited by flammability. In this study, a flame retardant, ammonium polyphosphate (APP), biopolymer, chitosan (CS), were added polyvinyl alcohol (PVA), polymer was further crosslinked using boric acid (H3BO3). PVA aerogels, negatively charged APP positively CS formed polyelectrolyte complex (PEC) through ionic interaction. Cone calorimetry vertical burning tests (UL-94) indicated that composite excellent retardancy; they could decrease heat release rate, total carbon dioxide (CO2) generation. Both PVA/H3BO3 APP-CS in aerogel be burned carbon, foamed char layer act together impart with good retardancy. Further, temperature at backside increasing content, as determined flame-spraying experiment, can also serve thermal insulation materials. This work provides an effective promising method for preparation retardancy property construction