Abstract: PMMA/fly ash/Mg(OH)2 composites were prepared through gradient temperature bulk polymerization. The microstructure of the composite was viewed by using JCM5000 desktop scanning electron microscope (SEM). Its combustion and heat insulation performance had been studied. When the loading of Mg(OH)2 was 35 phr, its fire retardant level was HB. When the content of the fly ash was 60~80 phr, and the sample thickness was less than or equal to 20 mm, and its heat insulation effect was very good.

Key words: composite, fire retardant, heat insulation, fly ash, magnesium hydroxide, polymethyl methacrylate