Abstract: Two types of aluminum trihydrate (ATH), with or without surface treatment, and mica were incorporated into TPU composites. The flame retardancy of these composites was subjected to vertical burning (UL 94) and oxygen index test. When the loading of ATH was between 70 and 80 phr, the composites showed a good flame retardacy with those containing surface treated ATH being better. The inclusion of mica did not affect the flame retardancy of the composites. However, it may improve the processability of the composites.

Key words: polyurethane thermoplastic, elastomer, aluminum trihydrate, mica, flame retardant