Microencapsulated melamine phosphate via the sol–gel method and its application in halogen‐free and intumescent flame‐retarding acrylonitrile‐butadiene‐styrene copolymer

In this paper, a facile method is introduced to modify melamine phosphate ( MP ) via the sol–gel process. The aim was simultaneously to increase the water resistance of MP and improve the dispersion and compatibility of MP in acrylonitrile‐butadiene‐styrene copolymer ( ABS ). In addition, the incorporation of SiO 2 particles into the MP /dipentaerythritol ( DPER ) system can further ameliorate the char‐forming ability and enhance the flame retardant properties of polymer composites. The chemical structure and surface morphology of SiO 2 @ MP were confirmed and observed by Fourier transform infrared ( FTIR ) spectroscopy, SEM and TEM , respectively. The results demonstrate that ABS / SiO 2 @ MP / DPER (3/1) at a loading of 30 phr reaches 31.2% limiting oxygen index and achieves a UL ‐94 V‐0 rating. Moreover, FTIR spectra indicate that the main char‐forming process of the SiO 2 @ MP / DPER system occurs at 365–420 °C. A potential condensed flame retardant mechanism of SiO 2 @ MP and DPER in ABS composites is proposed via the systematic analysis of char residue after combustion by FTIR spectroscopy, SEM and X‐ray photoelectron spectroscopy.