SBIR Phase I: Mesoporous Nanoparticle Flame Retardants

This Small Business Innovation Research Phase I project investigates the properties of mesoporous silicate nanoparticles and the use of these particles as non-toxic, char-forming flame retardants (FRs) for thermoset and thermoplastic polymers. The project elucidates the relationship between the physiochemical properties of the silicate compositions (e.g., surface area, pore size, pore volume, surface polarity and chemical composition) and the effectiveness of the mesophases in forming carbonaceous and ceramic chars that function as a barrier toward the three components that support combustion (heat, oxygen, and volatile fuel). In order to accomplish this objective, the quality of the two forms of char is being improved by doping the silicate surfaces to enhance catalytic surface acidity (carbonaceous char) and by integrating the silicates with low temperature inorganic sintering aids (ceramic char). The research program also investigates the dispersion of conventional FR agents within the framework's pores and surfaces for improved flame retardant efficacy through synergistic and additive interactions with the silicate mesophase. The multi-component FR formulations of interest include agents that function in the condensed phase (e.g., intumescent polyphosphates, endothermic metal hydroxides) and the gaseous phase (e.g., molecular phosphorus agents and halogenated compounds). The broader impact/commercial potential of this project is to further the global efforts to reduce the consumption of halogenated flame retardant agents in polymers, due to their negative impact on the environment when they are produced, discarded, and/or burned. Manufacturers are further challenged because the addition of all existing FR compounds diminishes the mechanical properties of the polymer into which they are compounded. The outcome of this project will directly address both of these concerns. Our completely non-toxic, silica-based, mesoporous nanoparticles provide both flame retardation and mechanical property enhancement for a broad range of polymers. The proposed research provides a number of broad, societal and commercial impacts. Further improving the efficacy of mesoporous silicate compositions as FR agents for polymers will advance knowledge by yielding a better understanding of the mechanisms underlying the combustion of plastics. Scaling our production facility to meet customer demand will result in job creation and increased use of environmentally friendly and domestically sourced raw materials. As these products become broadly adopted, both domestically and around the world, human exposure to endocrine-active chemicals will be reduced, in accord with the anticipated reduction of dependence on halogenated FR agents.