▎ 摘　　要

In this manuscript, an in situ layered intumescent flame retardant (IFR) of graphene oxide (GO) was used to produce a polybutylene terephthalate (PBT) flame-retardant material with different flame-retardant concentration gradients. IFR was introduced into the GO layered structure via a chemical reaction to achieve an in situ flame-retardant effect. The elements of the composite were characterized using energy dispersive spectroscopy. The results showed that although the subsequent PBT-based flame-retardant composites displayed low flame-retardant content, it exhibited excellent flame retardancy and mechanical properties. Due to the introduction of GO, the flame retardancy of the composites was improved significantly. The lamellar structure of GO provided a barrier allowing it to absorb condensed nucleus compounds. Therefore, continuous and compact scaly carbon layers were formed in the matrix during the burning process.