Abstract: In this study， flame-retardant reinforced PBT compounds were prepared through a multi-component combination of halogen flame retardants with phosphorus， nitrogen， and phosphorus-nitrogen-based flame retardants， and their glow-wire ignition temperature （GWIT） was investigated. Brominated polystyrene， antimony trioxide， diethylaluminum hypophosphate， melamine cyanurate， melamine polyphosphate， and carbon-based composite halogen-free flame retardant were used as flame retardants to compound with the reinforced PBT for flame-retardant experiments. The enhanced PBT compound only with halogen flame retardant or with halogen-free flame-retardant system cannot meet the requirements of IEC60335-1 for the GWIT of current carrying components in unmanned electrical appliances. By a combination of different types of flame retardants and the use of bromine-nitrogen-phosphorus synergistic flame retardant， the enhanced PBT could ultimately achieve the best flame-retardant performance and simultaneously meet the requirements of flame-retardant standard at GWIT>825 ℃， GWFI>960 ℃， and UL 94 V-0.

Key words: polybutylene terephthalate, flame retardant, high glow-wire ignition temperature, ignition temperature, reinforcement