Institute of Safety Science and Engineering, School of Mechanical and Automotive Engineering, South China University of Technology, Wushan Road 381, Guangzhou 510641, P. R. China.
Soft Matter. 2021 May 26;17(20):5231-5239. doi: 10.1039/d1sm00435b.
Wood is one of the oldest building materials and commonly employed in construction. However, the inherent fire hazard of wood restricts its practical application. Application of fire retardant coatings has been proved to be a highly efficient method for improving the fire retardancy of structural materials during combustion. However, developing sustainable, renewable and environmentally-friendly coatings is challenging because of the dependence on traditional flame retardants. In this study, a self-healable, fully-recyclable and biodegradable biogel coating was proposed, derived entirely from natural and food-safe constituents, which has rarely been demonstrated for wood safety. A uniform and strongly-adhesive coating could be obtained on wood surfaces via a facile preparation process without compromising the inherent mechanical properties of wood. Meanwhile, the coating showed excellent self-healing properties after damage, full degradability and good recyclability when disposed. Remarkably, biogel-coated wood exhibited enhanced fire-retardant properties, reflected by a 24.0% decrease in peak heat release rate and 17.2% reduction in total heat release with a 350 μm thick coating, along with a sixfold enhancement in ignition delay time and self-extinguishing behavior. We merged all merits in one fire-retardant coating which can be easily reproduced, and is low cost and scalable, making the biogel-coated wood a promising candidate for widespread application in green buildings.
木材是最古老的建筑材料之一，常用于建筑。然而，木材固有的火灾隐患限制了其实际应用。阻燃涂料的应用已被证明是提高结构材料在燃烧过程中阻燃性的一种非常有效的方法。然而，由于依赖传统的阻燃剂，开发可持续、可再生和环境友好的涂料具有挑战性。在本研究中，提出了一种自修复、完全可回收和可生物降解的水凝胶涂层，完全由天然和食品安全成分制成，这在木材安全方面很少有报道。通过简单的制备工艺，可以在木材表面获得均匀且具有强附着力的涂层，而不会损害木材的固有机械性能。同时，该涂层在损坏后表现出优异的自修复性能，完全可降解，当处理时具有良好的可回收性。值得注意的是，水凝胶涂层木材表现出增强的阻燃性能，其峰值放热率降低了 24.0%，总放热量降低了 17.2%，涂层厚度为 350 μm，点火延迟时间提高了六倍，具有自熄行为。我们将所有优点集于一身，形成一种易于复制、成本低且可扩展的阻燃涂料，使水凝胶涂层木材成为广泛应用于绿色建筑的有前途的候选材料。
