ENHANCED FIRE RETARDANCY BY USING LARGE SURFACE AREA OF POLYALUMINUM HYDROXIDE ON SILICA SPHERES

Fire retardancy was greatly enhanced by using large surface area of polyaluminum hydroxide (PAH) attaching on the surface of uniform size silica spheres. The PAH was synthesized on the surface of silica spheres by simple hydrolysis and condensation reaction using KOH or NH4OH as a catalyst. Although partial segregation between silica spheres and PAH was observed when KOH was used as a catalyst, there was no such segregation was observed when NH4OH was used as a catalyst. Characteristic absorption peaks of Al-OH and Si-O-Al were detected by FTIR spectra after completely washing silica spheres. Field emission scanning electron microscope (FESEM) images show large amount of long chain of PAH. Various amounts of PAH were attached on the surface of silica spheres and mixed with cellulose acetate for testing fire retardancy. The fire retardancy was greatly enhanced by increasing the amount of PAH and proved by FESEM images.