THERMAL-DEGRADATION OF FLAME-RETARDANT COMPONENTS IN FILLED AND UNFILLED ABS PLASTICS

The thermal degradation of filled and unfilled flame-retarded acryloni trile-butadiene-styrene (ABS) plastics was studied using X-ray and SEM analyses. It was shown that the inorganic filler CaCO3 changes the ki netics of the reactions that take place during the thermal degradation of flame-retarded ABS, although CaCO3 does not take part in the react ions. The formation of a char laver on the surface of the plastic was observed when ABS was filled with CaCO3. This char layer decreases the diffusion of oxygen into the specimen and diffusion of the flammable pyrolysis products out. A more homogeneous char layer was obtained whe n an organic flame-retardant was polymerized on the surface of the CaC O3.