Study on surface modification and flame retardants properties of ammonium polyphosphate for polypropylene

Microencapsulation ammonium polyphosphate used as flame‐retardant in polypropylene was prepared with hydroxyl silicone oil (HSO) and melamine‐formaldehyde (MF) resin in this article. Fourier transform infrared and energy dispersive spectrometer were used to identify the structure of HSO‐MFAPP. For the HSO‐MFAPP/polypropylene (PP) composites, the flame retardant effect was evaluated by the limiting oxygen index and UL‐94 testing, the compatibility was observed with scanning electron microscope, and the thermal stability was studied by thermogravimetric analysis. The results showed that the microencapsulation of ammonium polyphosphate (APP) with HSO‐MF was prepared by in situ polymerization, and the flame retardant properties and water resistance of the PP/HSO‐MFAPP/pentaerythritol (PER) composites were much better than the ones of the PP/APP/PER composites. Moreover, the compatibility of HSO‐MFAPP with PP was better than that of unmodified APP. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012