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

Abstract

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.