Effect Of Hydrophobic Modification Of The Flame Retardant On The Properties Of The Water-borne Intumescent Fire Retardant Coatings

Water-borne intumescent fire retardant coatings become an important development trend because of its low energy consumption and low volatile organic compound. But their comprehensive properties may be influenced because of poor water resistance of the flame retardant. Therefore, hydrophobic modification of the flame retardant is needed.The surface of the flame retardant was treated by hydrophobic modifiers in physical methods which had the advantages of short-cut process, low cost and convenient post-processing in this dissertation. First, the water resistance, fire resistance, acid and alkali resistance of the fire retardant coatings have been investigated after ammonium polyphosphate (APP) modified by hydrophobic modifiers. Next, effect of interaction between modified PER and modified APP on the water resistance of the fire retardant coatings has been investigated. Finally, interaction among the components of the fire retardant coatings and effect of the surface modification of the flame retardant on this interaction has also been investigated by thermal gravimetric analysis. The key works and conclusions were listed as following:The water resistance was effectively improved with modified APP in physical method. Methylsilicone oil showed better hydrophobicity by the water-soluble and water resistance testing. Fire retardant coatings after modification showed better water resistance without bubbles after 48 h water resistance testing. The residual weight of the fire retardant coatings increased after adding methylsilicone oil. The residual weight increased by 5% at 800℃. Modified APP with methylsilicone reduced the back temperature, improved the fire resistance. But modified APP with methylsilicone had less effect on the acid and alkali resistance of the fire retardant coatings. Carbon foam became more uniform with increase of content of methylsilicone oil.The synergistic effect of modified APP and modified PER strongly improved the water resistance of the fire retardant coatings, which showed better water resistance than the fire retardant coatings with modified APP, as well as that with modified PER. Synergistic effect existed not only among the flame retardants, but also between the flame retardants and BP108. This synergy improved the high-temperature heat stability of the residues. The obvious synergy between silicone fluid and the components of fire retardant coatings improved the residual weight. The effect of methylsilicone oil on thermal behavior of APP was larger than PER. The residual weight of modified APP increased by 14% than unmodified APP at 800℃. The residual weight of the fire retardant coating with modified APP increased by 4% than that with modified PER, as well as that with modified APP and modified PER at 800℃.