Influences of montmorillonite on fire protection, water and corrosion resistance of waterborne intumescent fire retardant coating for steel structure

• Published in: Surface & coatings technology Vol. 239; pp. 177 - 184
• Main Authors: Wang, Junbo, Wang, Guojian
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 25.01.2014; Elsevier
• Subjects: Applied sciences; Corrosion; Corrosion environments; Corrosion resistance; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fire protection; Fire retardant coating; Materials science; Metals. Metallurgy; Organic-modified montmorillonite (OMMT); Physics; Production techniques; Surface treatment; Surface treatments; Water resistance; Corrosion resistance; Fire retardant coating; Fire protection; Water resistance; Organic-modified montmorillonite (OMMT); Metallic structure; Water corrosion; Surface treatments; Coatings; Protection
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2013.11.037

Organic-modified montmorillonite (OMMT) was used as nano-layer filler to improve the fire protection, water and corrosion resistance of waterborne intumescent fire retardant coating. The influence of OMMT on the properties of fire retardant coating and the mechanism of OMMT effect on the coating were investigated in detail by X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric (TGA) analysis, Fourier transform infrared spectroscopy (FTIR), fire protection test, water and corrosion resistance test. It was found by XRD that OMMT could be exfoliated and dispersed well in the coating with the addition of 1wt.%, while excessive OMMT was easy to aggregate and dispersed badly. SEM micrographs and EDS analysis results showed that well-dispersed OMMT nano-layers were parallelly distributed in the coating. The results of fire protection test and the observation results of morphology of char layers indicated that the fire protection of the coating and foam structure of the char layer were remarkably improved by adding suitable content of OMMT. TGA analysis demonstrated that OMMT could enhance the combustion residual weight and thermal stability of the coating. Based on the results of water and corrosion resistance test, the parallel-arranged OMMT could significantly slow down the migration and solvation of fire retardant additives through its barrier effect, thereby improving the water and corrosion resistance of the coating. •Suitable OMMT could be exfoliated and parallelly distributed in the coating.•Excessive OMMT produced negative effect on the properties of the coating.•OMMT improved fire protection and char layer of the coating by barrier effect.•The thermal property of the coating was enhanced by adding OMMT.•Parallel-arranged OMMT could delay the escape of fire retardant additives.