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 SiO2 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 SiO2@MP were confirmed and observed by Fourier transform infrared (FTIR) spectroscopy, SEM and TEM, respectively. The results demonstrate that ABS/SiO2@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 SiO2@MP/DPER system occurs at 365–420 °C. A potential condensed flame retardant mechanism of SiO2@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. © 2015 Society of Chemical Industry Microencapsulation process of MP via sol‐gel method