Fire retardant materials-filler flame retardant When inorganic fillers are used as flame retardants, the negative impact of fillers on the properties of polymer substrates should be minimized, the combustible components generated by high temperature cracking of materials should be reduced, and the thermal physical properties of materials should be improved. Prevent physical transformation of fillers.


Asbestos, talc, mica powder, wollastonite powder, etc., can also be used as flame retardants. They are actually fillers, and their flame retardant mechanisms include dilution, heat storage, heat conduction, cooling, surface effects, etc. to the polymer. Fillers can be divided into two categories, active and inert, but this classification is only relative. For example, below 900°C, asbestos is only an inert diluent with low thermal conductivity, but at 900°C to 1400°C, asbestos can release crystal water; when above 1400°C, asbestos can undergo an endothermic reaction that changes its chemical structure , and some components in asbestos may also react with some thermal degradation products of high polymers, and asbestos becomes an active filler. When inorganic fillers are used as flame retardants, the negative effects of fillers on the properties of polymer substrates should be minimized, the combustible components generated by pyrolysis of materials should be reduced, the thermal-physical properties of materials should be improved, and physical transformations of fillers should be prevented. It is worth noting that some inorganic compounds that can be used as flame retardants are catalysts for polymerization and polycondensation reactions, and they also have catalytic effects on the combustion or decomposition products of polymers, so they can promote char formation. For example, certain titanium, cobalt oxides, etc. can catalyze the dehydrocyclization and aromatization of polyolefins. [2]