Effects of Si/Al, Na/Al, and H2O/Na2O molar ratios on formaldehyde barrier properties of inorganic aluminosilicate coatings

• Published in: International journal of minerals, metallurgy and materials metallurgy and materials, 2021-11, Vol.28 (11), p.1868-1874
• Main Authors: Xiong, Shan-xia, Kuang, Jian-lei, Zheng, Qian-fang, Xiao, Ting, Liu, Wen-xiu, Wang, Qi, Jiang, Peng, Cao, Wen-bin
• Format: Article
• Language: English
• Subjects: Adhesives; Aluminosilicates; Aluminum; Aluminum silicates; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Coatings; Composites; Corrosion and Coatings; Degree of polymerization; Formaldehyde; Fourier transforms; Glass; Marine corrosion; Materials Science; Mechanical properties; Metakaolin; Metallic Materials; Natural Materials; Panels; Particle size; Ratios; Silica; Silica fume; Silicon; Sodium hydroxide; Surfaces and Interfaces; Thickness; Thin Films; Tribology; Urea; Urea formaldehyde resins; VOCs; Volatile organic compounds
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-020-2197-7

Wood-based panels containing urea-formaldehyde resin result in the long-term release of formaldehyde and threaten human health. In this study, inorganic aluminosilicate coatings prepared by combining metakaolin, silica fume, NaOH, and H 2 O were applied to the surfaces of wood-based panels to obstruct formaldehyde release. The Si/Al, Na/Al, and H 2 O/Na 2 O molar ratios of the coatings were regulated to investigate their effects on the structure and formaldehyde-resistant barrier properties of coatings. Results showed that the cracks in the coatings gradually disappeared and the formaldehyde resistance rates of the barrier increased as the Si/Al molar ratio was increased from 1.6 to 2.2. This value also increased as the Na/Al molar ratio was increased from 0.9 to 1.2 because of the improvement of the degree of polymerization. As the H 2 O/Na 2 O molar ratio was increased from 12 to 15, the thickness of the dry film decreased gradually and led to the reduction in the formaldehyde resistance rate. When the Si/Al, Na/Al, and H 2 O/Na 2 O molar ratios were 2.2, 1.2, and 12, respectively, the inorganic aluminosilicate coating showed good performance as a formaldehyde-resistant barrier and its formaldehyde resistance rate could reach up to 83.2%.