Synergistic effect of silica sol and K2CO3 on flame-retardant and thermal properties of wood

• Published in: Journal of thermal analysis and calorimetry 2017-05, Vol.128 (2), p.825-832
• Main Authors: He, Shaorui, Wu, Weihong, Zhang, Mengjiao, Qu, Hongqiang, Xu, Jianzhong
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Carbon dioxide; Chemistry; Chemistry and Materials Science; Combustion; Degradation; Fire resistance; Flame retardants; Flammability; Inorganic Chemistry; Leaching; Mass spectrometry; Measurement Science and Instrumentation; Physical Chemistry; Polymer Sciences; Potassium carbonate; Residues; Silicon dioxide; Stability analysis; Synergistic effect; Thermal analysis; Thermal resistance; Thermodynamic properties; Thermogravimetry
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-016-5947-z

In this study, silica sol (SiO 2 sol) and K 2 CO 3 were used as flame retardants for wood. The synergistic effect of SiO 2 sol and K 2 CO 3 on the flame retardancy, leaching resistance, and thermal properties of wood was investigated. The limiting oxygen index results revealed a significant improvement in the flame retardancy and leaching resistance of the wood sample treated with K 2 CO 3 and SiO 2 sol using the double bath technique. The thermal analysis results showed that the synergistic effect of K 2 CO 3 and the SiO 2 sol effectively prolonged the degradation of the wood sample during the charring stage and improved the stability of the char residue. The thermogravimetry–mass spectrometry analysis and scanning electron microscopy results showed that K 2 CO 3 catalyzed the degradation reaction of the wood sample at lower temperatures resulting in an increase in the water and carbon dioxide output, and the SiO 2 sol formed a compact and melted barrier on the surface of the char residue, which hindered the transfer of heat and combustible gases in the condensed phase. Thus, the combination of K 2 CO 3 and SiO 2 sol proves to be a promising flame-retardant system for wood.