Synthesis of MoO3 with different morphologies and their effects on flame retardancy and smoke suppression of polyurethane elastomer.

Molybdenum trioxide (MoO₃) microrods, nanofibers, and nanoplates were synthesized via the hydrothermal method and high-temperature calcination method, respectively. Then the MoO₃ was added into polyurethane elastomer, respectively. The flame retardancy and smoke suppression of the composites added with different MoO₃ were studied by thermal gravimetric analysis, cone calorimeter, and smoke density. The results show that the three kinds of MoO₃ with different morphologies could promote the formation of char and possess flame retardancy and smoke suppression, and MoO₃ nanofibers exhibit a higher degree of flame retardancy, and 1 wt% addition could make the peak heat release rate of polyurethane elastomer composites reduce from 881.6 kW m⁻² for a pure sample to 343.4 kW m⁻², a decrease by 61.0%. As for smoke suppression, MoO₃ nanoplates possess the best smoke suppression; 5 wt% could decrease a pure sample's smoke density by 41.3% from 361 to 212. Moreover, the char residue of composites after combustion was analyzed by Raman spectra and X-ray photoelectron spectroscopy, and the flame retardancy and smoke suppression mechanisms of MoO₃ were discussed. [ABSTRACT FROM AUTHOR]