Synergistic Flame Retardant of Acid or Alkali-treated Montmrillonite/Phosphate Flame Retardant in PC/ABS Blends

Acid-treated montmrillonite(a-MMT) and alkali-treated montmrillonite(b-MMT) were prepared by modifying Na-montmorillonite(Na-MMT) with hydrochloric acid or sodium hydroxide,which were used with phosphate to synergistic flame retard polycarbonate/acrylonitrile-butadiene-styrene(PC/ABS) blends.Effects of a-MMT and b-MMT on the flammability property and thermal stability of the blends were investigated by X-ray diffraction(XRD),thermogravimetry(TG),microscale combustion calorimeter(MCC),scanning electron microscope(SEM) and so on.The results show that 1,3-benzenenediol polymer with phosphoric trichloride phenyl ester(BDP) modified montmorillonite(BDP-MMT) decreased the initial decomposition temperature of the flame retardant PC/ABS blends,while a-MMT and b-MMT increased it.The addition of BDP-MMT deteriorated the barrier property of carbon layer.But a-MMT and b-MMT enhanced the thermal stability of carbon layer and delayed the time of second peak of heat release rate(PHRR2).Moreover,PC/ABS blends flame resisted by montmrillonite treated with proper acid concentration were classified as UL-94 V-0.