Graphene-Borate as an Efficient Fire Retardant for Cellulosic Materials with Multiple and Synergetic Modes of Action

Abstract

To address high fire risks of flamable cellulosic materials, that can trigger easy combustion, flame propagation, and release of toxic gases, we report a new fire-retardant approach using synergetic actions combining unique properties of reduced graphene oxide (rGO) and hydrated-sodium metaborates (SMB). The single-step treatment of cellulosic materials by a composite suspension of rGO/SMB was developed to create a barrier layer on sawdust surface providing highly effective fire retardant protection with multiple modes of action. These performances are designed considering synergy between properties of hydrated-SMB crystals working as chemical heat-sink to slow down the thermal degradation of the cellulosic particles and gas impermeable rGO layers that prevents access of oxygen and the release of toxic volatiles. The rGO outer layer also creates a thermal and physical barrier by donating carbon between the flame and unburnt wood particles. The fire-retardant performance of developed graphene-borate composite and mechanism of fire protection are demonstrated by testing of different forms of cellulosic materials such as pine sawdust, particle-board, and fiber-based structures. Results revealed their outstanding self-extinguishing behavior with significant resistance to release of toxic and flammable volatiles suggesting rGO/SMB to be suitable alternative to the conventional toxic halogenated flame-retardant materials.

Establishment of the mechanism and fireproof efficiency of wood treated with an impregnating solution and coatings

“…It agrees with data known from articles [7,10], whose also attributed a change in the process of smoke generation when treated with swelling coatings. In contrast to research results [8,11], obtained data on the influence of a coating on the process of the formation of a foamed layer of coke and a change in the thermal insulation properties allow us to argue that: -the main regulator of the process of thermal insulation is not only the formation of a layer of coked cellular material but thermal resistance of a fireproof coating; -a significant impact on the process of transition of a combustible material at application of a fireproof coating is exerted by a transition to the group of materials that are difficult to ignite, which spread the flame over surface slowly at low smoke-generating capacity.…”

“…In most cases, they are modified with polymer complexes and flame retardants, but such coatings relate to the mate- [7,8].…”

“…Research into determining a group of flammability of wood, the Flame Spread Index and smoke generation, treated with impregnating solutions and the coating was carried out in accordance with [8].…”

Influence of dry mixtures in a coating on the effectiveness of wood protection from the action of a magnesium flame

“…Their authors also associate a change of the process of swelling with the addition of mineral fillers. In contrast to the results of studies [11,12], the obtained data on the influence of fillers on the process of transition of a coating to a foamed layer of coke and the change of insulation properties gives opportunity to state the following:…”

“…They are modified by polymeric complexes and fire-retardant agents in most cases, but such coatings relate to easily washable materials and are suitable for indoor spaces [10,11].…”