Novel high-performance sustainable polyurethane nanocomposite foams: Fire resistance, thermal stability, thermal conductivity, and mechanical properties

Owing to the pervasive global consciousness surrounding environmental concerns, there has been a growing need for the development of sustainable insulating materials and diminishing the dependence on petrochemical resources. In this study, liquefied bio-polyol from bamboo powder was used in bio-based rigid polyurethane foams (B-PU) incorporating nano silica (3–7 php) and different environmentally halogen-free flame retardants (FRs) including aluminum diethyl phosphinate, diammonium phosphate, and aluminum trihydroxide. The purpose of this study was to investigate the influence of nano silica and flame retardants on cell structure, flammability, thermal properties as well as apparent density, and mechanical property of B-PU. B-PU with optimized nano silica and additives had an LOI value above 21% and passed the V-0 rating. The cone calorimeter test indicated that the peak heat release rate of the nanocomposite foams in the presence of FRs was reduced by 32.37–41.68% compared to that of neat B-PU nanocomposite. Moreover, the compressive strength and thermal properties of flame-retardant nanocomposite foams, compared to neat B-PU, were significantly improved. Finally, the B-PU foam and its nanocomposites demonstrated effective thermal insulation with a low thermal conductivity range when compared with other current bio-based insulation panels. The findings of this research hold significant implications for the progress in fabricating polyurethane nanocomposites derived from biomass resources, which exhibit great flame retardancy and high insulation performance, possess heightened thermal stability, and align with the ongoing path of sustainable development investigations.