Study on Flame Retardancy of PBT Matrix Composites With Layered Gradient Structure

In order to solve the problem of low flame retardant efficiency caused by the traditional composite preparation process. Firstly, nano antimony trioxide (nano-Sb2O3) was compounded and modified by cetrimonium bromide(CTAB) and 3-glycidoxypropyltrimethoxysilane(KH560), and then nano-Sb2O3 composites with gradient distribution of nano-Sb2O3 were prepared by utilizing the laminated hot pressing technique. The results show that: CTAB and KH560 are successfully coated on the surface of nano-Sb2O3; the content of the Sb element shows a gradient distribution from top to bottom of the composite section with the pattern of high-low-high. Compared with the homogeneous composites, the flame retardant properties of gradient composites are improved. Among them, the LOI of G828 gradient composite material was increased by 6%. The HRR and SPR of G747, G828, and G909 are higher than those of homogeneous composites at the beginning and the end of combustion, and G828 has the best flame retardant performance among the different gradient structures, with its THR decreasing by 10% and TSP decreasing by 13%.