Treatments and modification to improve the reaction to fire of wood and wood based products—An overview

Abstract

SUMMARYWood and wood‐based products are widely used for structural building elements, but due to their composition, they are susceptible of combusting if exposed to fire. Fire safety is an important issue of building safety, especially when the building's fire load contents enhance the risks of fire spread. Therefore, the involved materials are very important to address the fire safety requirements. When existing timber structures are involved, the most usual way to improve its reaction to fire is to treat wood with fire retardant materials.The idea of this paper is to give an overall overview, on the existing fire‐retardant and intumescent coating materials, modification, and treatments that can be applied to wood and wood‐based products in order to improve their reaction to fire.

The Flame Retardancy of Polyethylene Composites: From Fundamental Concepts to Nanocomposites

“…In addition to the water-soluble boron compounds including sodium borate (borax), BA, and boron oxide, water-insoluble ones and more commonly ZBs, are widely used as boron-derived FRs, former for application in cellulosic materials and latter in thermoplastics [52]. Boron based FRs possess low cost, high thermal stability, non-toxicity, and ease of handling, which have resulted in their wide use in PE systems [90]. Employment of ZB, with the most commercial importance, not only improves flame retardancy but also helps with the smoke suppression and anti-arcing in condensed phase [52].…”

“…Silicon-containing FRs always have been in the frontline of co-additives in FR systems for PE products due to their high versatility, compatibility, low toxicity, and environmentally friendly characteristics [47,97]. This class of compounds can be mainly categorized into silicones, silica, organosilanes, silsesquioxanes, and silicates, functioning in FR systems as additives or other forms [52,90]. Silicon-comprising materials are inherently thermal stable and during a fire, they can produce an insulative layer upon decomposition.…”

“…The reduction of HRR, PHR rate in CCT, and the rate of combustibles are most evident in silicone and siloxane. Besides fire retardancy through the condensed phase, the functionalization of silicone-based FRs with phosphorous or nitrogen groups makes them more efficient through contribution to the gas phase by trapping of dynamic radicals in the vapor phase [90,125].…”

Evaluation of Mechanical and Flame Retardant Properties of Medium Density Fiberboard Using Artificial Neural Network

“…When the acids in the wood combine with acidic fire retarding agents, they can destroy most formations of the wood such as hemicellulose and cellulose that are the main elements solidifying the wood by the hydrolysis process and can decrease the length of the cellulose molecule and reduce the strength properties in micro dimensions (Popescu and Pfriem, 2020). During this cellulose depolymerization, the increase in the brittleness of the panels treated by acidic fire retarding agents such as ammonium phosphate can be due to the brittleness of the wood fibers as a result of the formation of crystals…”

“…According to the studies conducted, it became clear that as the level of fire retarding agents such as borax increases during TG test, the level of the flammable gases decreases in the compound (Baysal, 2002). Exothermic reactions occurring during cellulose firing result in the formation of flammable gases and create less charred residues (Popescu and Pfriem, 2020). In the presence of the fire retardants, not only there is a lower exothermic temperature, but also other exothermic reactions related to two other substances making the cell wall are also cancelled out.…”