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

Autor: Qianfang Zheng, Xiong Shanxia, Peng Jiang, Qi Wang, Ting Xiao, Wenbin Cao, Jianlei Kuang, Wenxiu Liu
Rok vydání: 2021
Předmět:
Zdroj: International Journal of Minerals, Metallurgy and Materials. 28:1868-1874
ISSN: 1869-103X
1674-4799
DOI: 10.1007/s12613-020-2197-7
Popis: 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 H2O were applied to the surfaces of wood-based panels to obstruct formaldehyde release. The Si/Al, Na/Al, and H2O/Na2O 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 H2O/Na2O 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 H2O/Na2O 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%.
Databáze: OpenAIRE
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