Synthesis of fire retardants based on N and P and poly(sodium silicate-aluminum dihydrogen phosphate) (PSADP) and testing the flame-retardant properties of PSADP impregnated poplar wood

Abstract

The development of fire retardants (FRs) is an approximative process of optimization. In this context, a novel water-soluble formulation with poly(sodium silicate-aluminum dihydrogen phosphate) (PSADP) has been developed, aiming at reduced hygroscopicity and enhanced leaching resistance of poplar wood in combination with nitrogen-phosphorus (NP) FR (FRNP). After treatment of wood with FRNP and PSADP in vacuum, the following data of the samples were determined: rate of hydroscopicity, leaching resistance, heat release rate (HRR), total HR (THR), effective combustion heat, mass loss, and concentration of flue gas. FR distribution in the wood’s inner surface was investigated by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDXA). Results show that PSADP and FRNP have favorable synergistic effects on moisture resistance and flame retardance. Smoke density (SD) of NP and PSADP treated samples shows a significant reduction relative to that of NP. NP-PSADP treated samples form more char with carbon layers of higher density. At the same time, FRNP-PSADP is evenly distributed over the inner wood surfaces and penetrates the cell cavities of the poplar wood.

Polymeric Micro- and Nanosystems for Wood Artifacts Preservation

“…The consolidation effect of the polymer resins is significantly improved by the nanodispersion in these solutions of mineral materials with reinforcing effect (especially metal oxides) [37]. The nanoinsertions of these nanocomposites into the wood support, besides the role of physical consolidation, also provide an important increase in resistance to oxidative and biological degradation (fungus mildew) and increased flame retardancy [38][39][40][41]. The most suitable polymers for wood preservation are aliphatic and aliphatic epoxy acrylic resins due to their stability to oxidative degradation, their adhesion, and processability.…”

“…Systems containing both phosphorous and nitrogen components are good substitutes for halogenated FR due to their synergistic effect [38,39]. In [40], nitrogen-phosphorous FR dispersed in poly(sodium silicate-aluminum dihydrogen phosphate) (PSADP) was used to reduce poplar wood hygroscopicity and to improve its fire resistance. These two components present a synergic effect on the two properties being distributed over the inner surface and penetrate the cell cavities of wood.…”

Surface Characteristics of Poplar Wood with High-Temperature Heat Treatment: Wettability and Surface Brittleness

“…Many studies have used different modification processes, including acetylation, fire retardants, preservatives, impregnation with resins, as well as heat treatment, to improve wood performance (Esteves and Pereira 2009;Hamdan and Islam 2012;Ajdinaj et al 2013;Adebawo et al 2015;Kumar et al 2015;Zhang et al 2015). Unlike other modifications, heat treatment is one of the oldest and most environmentally friendly, and it has recently received renewed interest because of the limitations on the use of natural lumber and restrictive regulations on the use of toxic chemicals (Hillis and Rozsa 1985;Boonstra et al 2006a,b).…”

Functionalized Surface Layer on Poplar Wood Fabricated by Fire Retardant and Thermal Densification. Part 1: Compression Recovery and Flammability

“…This indicates that the compression was mostly in the surface layer (about 3 mm). It has been reported that the NP has a catalytic dehydration effect on wood polysaccharides during HT [32], and this could also make the wood surface layer more likely to be compressed because of the softening effect at higher moisture and temperature conditions [25]. From NP fire retardants can be produced softener-NH 3 , which reduces glass transition temperature of lignin, i.e., decrease Tg from approximately 170 • C [39].…”