Influence of phytic acid on flame retardancy and adhesion performance enhancement of poly (vinyl alcohol) hydrogel coating to wood substrate

作者：Zhao, Xiaojiong; Liang, Ziwei; Huang, Yubin; Hai, Yu; Zhong, Xiaodi; Xiao, Shu^*; Jiang, Saihua^*

来源：PROGRESS IN ORGANIC COATINGS, 2021, 161: 106453.

DOI：10.1016/j.porgcoat.2021.106453

• Phytic acid
• Hydrogel coating
• Enhanced adhesion
• Flame retardancy
• Mechanisms

Traditional fireproof strategies for wood mainly involve using organic flame retardants that may affect human health and environment, there is a need to explore a greener and nontoxic method. Herein, we proposed an easy to-process, environmentally friendly and highly efficient polyvinyl alcohol (PVA)/phytic acid (PA) hydrogel coating to improve flame retardancy of wood by freeze-thaw cycles. PA can promote the gelatinization of PVA and further enhance mechanical properties and flame retardancy of PVA coating. The obtained PVA/PA hydrogel coating shows better adhesion and fire-safety performance compared to pure PVA hydrogel coating, including achieving 151.68 kPa of adhesion strength, reaching V0 rating in UL-94 test, a significant enhancement of time to ignition (TTI, from 63 s to 130 s), and 51.47% and 55.47% decrease in the mean heat release rate (HRR) and total release rate (THR), respectively. The PVA/PA coating with enhanced superior adhesion and flame-retardant properties ensures the fire-safety of wood for its wide applications as structural materials in architecture and furniture fields.