Combustion resistant nanocomposites from water/AOT/MMA reverse microemulsions

Summary

A reverse microemulsion domain in the ternary water, AOT, and MMA (methyl methacrylate) system is reported at 22±1°C and compositions in this domain are polymerized at 70°C to produce nanocomposites of surfactant and water in PMMA. While limited microphase separation occurs during polymerization the resulting solids are translucent and no macroscopic phase separation occurs. Optical and thermal analysis indicates that the water is distributed uniformly throughout the nanocomposite and is mostly tightly bound to the surfactant headgroup and cannot freeze. The small amount of incorporated water that is freezable resides in pores or droplets about 12 nm or less in diameter. The translucency can be assigned to some sort of very limited microphase separation of the surfactant that occurs during polymerization. Ignition and TGA analyses indicate that the combustion resistance is mostly due to the incorporated AOT.