The Charring Effect and Flame Retardant Properties of Thermoplastic Elastomers Composites Applied for Cable

The halogen-free flame retardant (HFFR) thermoplastic elastomers (TPEs) composites filled with aluminum hypophosphite had been prepared by twin-screw extruder. The flame retardancy, thermal stability, charring-effect, mechanical and rheological properties of TPE composites had been investigated by cone calorimeter, limiting oxygen index (LOI), UL-94 (vertical flame) test, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), ultimate tensile and rheometer. The research results indicated that the flame retardancy and thermal stability of flame retardant (FR) TPEs had been dramatically improved. Obvious char-forming effect can be found for the samples with the addition of polyphenylene oxide (PPO) during high heat flow conditions, which presented more content and more compact of residue compared to the samples without PPO after combustion of cone calorimeter. Mechanical and rheological characteristics showed that the tensile strength and processability can be well maintained for FR TPEs composites, which was very important for industrial applications.