SYNTHESIS OF NOVOLAC-BASED CHAR FORMER AND ITS SYNERGISTIC EFFECTS WITH MAGNESIUM HYDROXIDE ON FLAME RETARDANCY OF POLYAMIDE-6

Abstract

A novel flame-retardant synergist,thermalplastic boron-containing phenol-formaldehyde resin(BPF),was designed and successfully synthesized to modify Magnesium hydroxide(MH) flame retardant polyamide-6(PA6).The synthesized BPF was characterized by FTIR,1H-NMR,XRD and TGA,etc.The experiment results showed that BPF possessed good charring performance,about 61.4 wt% solid residue remained even after heating to 750℃ for MH/BPF/PA6 system.The degraded BPF produced glassy B2O3 covering on the surface of the burning material,and effectively isolated the oxygen from interior material,therefore remarkably enhanced the flame retardancy of the material,reaching UL94-1.6mm V0 rating.BPF also served as an efficient lubricant and greatly improved the processability of the material.In addition,BPF did not deteriorate the mechanical properties of the flame retardant material,showing comprehensive modification effects on MH flame retardant PA6.