Synergistic effect of boron containing substances on flame retardancy and thermal stability of clay containing intumescent polypropylene nanoclay composites

The functions of nanoclay and three different boron containing substances, zinc borate (ZnB), borophosphate (BPO(4)), and boron silicon containing preceramic oligomer (BSi), were studied to improve the flame retardancy of polypropylene (PP)-nanoclay-intumescent system composed of ammonium polyphosphate (APP) and pentaerythritol (PER). The flame retardancy of PP composites was investigated using limiting oxygen index (LOI), UL-94 standard, thermogravimetric analysis (TGA), and cone calorimeter