The properties of glass fiber-reinforced polyethylene terephthalate (GF-PET) composites were investigated using limit oxygen index (LOI) measurement, vertical burning test, cone calorimeter test, thermogravimetric analysis, mechanical properties testing, and hot deformation temperature (HDT) testing. The results showed that appropriate amounts of boehmite (BM) and aluminum diethylphosphinate (ADP) in GF-PET had synergistic flame-retardant effects, and an appropriate amount of BM could improve the hot deformation temperature, mechanical properties, and thermal properties of the ADP/GF-PET composite. When 4% ADP was replaced by 4% BM, the 4-BM/ADP/GF-PET composite achieved a UL-94 V0 rating (2.0 mm) with an LOI of 31 vol%, and the peak of heat release rate (PHRR), average effective heat of combustion (AEHC), total heat rate (THR), and total smoke release (TSR) decreased by 13.9%, 16.7%, 18.8%, and 19.7%, respectively, while the time to ignition (TTI) and fire performance index (FPI) increased by 14.9% and 23.5%, respectively, compared with the ADP/GF-PET composite.

Keywords: boehmite, aluminum diethylphosphinate, synergistic flame-retardant effects, glass fiber-reinforced polyethylene terephthalate, hot deformation temperature.