Taiyuan Ligong Daxue xuebao (May 2024)
Effect of Mineral Fillers on Properties of Water-based Ultra-thin Fireproof Coatings
Abstract
Purposes The effects of different mineral fillers and their compound ratio on the properties of water-based ultra-thin fireproof coatings are worth studying. Methods Aqueous epoxy/acrylic composite emulsion was used as film material. Ammonium polyphosphate, pentaerythritol, and melamine were used as expansion systems. Titanium dioxide (TiO2), coal gangue (CG), bentonite (BT), and hydrotalc (LDH) were used as mineral fillers. Findings The results show that the fire resistance of single mineral filler is as follows: TiO2>CG>BT>LDH. When the single TiO2 filler fireproof coating burns for 80 min, the carbon expansion rate reaches 13.6, the back temperature of steel plate is 274.9 ℃, and the carbon layer structure is in strength weak. The compound mineral fillers can achieve the goals of high efficiency fire prevention, low energy consumption, cost-effectivenes and environmental protection, and provide a new way to the high value utilization of mineral fillers When m(TiO2)∶m(BT)∶m(LDH) composite ratio is 6∶2∶2, the expansion ratio of carbon layer is 14.9, and the back temperature of steel plate is only 268.8 ℃. When the m(TiO2)∶m(BT)∶m(CG) mixture ratio is 8∶1∶1, the expansion ratio is 14.5, the steel plate back temperature is only 261.0 ℃, and the fire resistance performance is better than that of single mineral filler. Scanning electron microscopy mages show that the addition of BT, CG, and LDH makes the surface structure of the carbon layer more compact and stronger. Infrared spectroscopy analysis results show that phosphide and metal oxides in the residue of burned carbon layer enhance the structural strength of the carbon layer. Thermal gravimetric analysis data show that the carbon residues of the two coatings are 36.35% and 36.92%, which improves the thermal shielding performance of the carbon layer.
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