Owing to their inherent flexibility, compressibility, breathability, and convenient fabrication process, polyurethane foam (PUF)-based triboelectric nanogenerators (TENGs) are an excellent choice for the development of energy harvesting devices and self-powered sensors. However, the vast majority of foams are victims of fire due to the extreme flammability of PUF. The addition of fillers during foam synthesis is proposed as a cost-effective means to overcome this problem. However, the addition of fillers significantly decreases the foamability and expansion ratio of the composite, thereby greatly affect the compressibility, flexibility, and density of the polymer/filler composite foam. Herein, a graphite (Gr)/carbon black (CB)/PU foam has been successfully fabricated using 1-butylimidazole diethylphosphonate ([Bmim]DEP) ionic liquid as a catalyst. During polymerization, [Bmim]DEP catalyzes the isocyanate/H<sub>2</sub>O reaction and generates CO<sub>2</sub> gas in the form of bubbles. These bubbles act as a blowing agent and enhance the foamability and expansion of the polymer/carbon composite. Thus, the resultant Gr/CB/PU sponge with high filler loadings (&gt;33 wt%) had low density and possessed excellent flexibility and compressibility. Besides, the resultant sponge exhibited excellent flame retardancy by self-extinguishing to a butane flame (~1400 °C, applied for 20 s) and reduce the peak heat release rate (a critical flammability metric) by 60%. Moreover, the addition of Gr and CB significantly enhanced the TENG performance of the foam. This work offers a new and facile strategy for fabricating flame-retardant and functional polymeric nanocomposites.

Ionic liquid-catalyzed synthesis of polymer/carbon nanocomposite foam: Enhanced flame-retardant and triboelectric performances

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.