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A tetrakis (melamine)‐1‐hydroxyethylidene‐1,1‐diphosphonic acid salt (EA‐MEL) was synthesized by a straightforward acid–base neutralization reaction between 1‐hydroxyethylidene‐1,1‐diphosphonic acid (EA) and melamine (MEL). This compound, which contains phosphorus and nitrogen elements, exhibits a 40% carbon residue at a temperature of 800°C. When combined with diethyl aluminium hypophosphite (OP1230) as a flame‐retardant composite in polylactic acid (PLA)/polyamide 11 blends through melt blending, a synergistic effect between the two flame retardants is observed. Consequently, the limiting oxygen index value significantly increases to 34.3, showcasing a remarkable 64.6% improvement. Additionally, the material achieves a V‐0 rating according to UL‐94 standards, and the peak heat release rate drops to 269 kW∙m−2 with the addition of just 5 wt% EA–MEL. These results demonstrate that EA‐MEL and OP1230 contribute to the generation of phosphoric acid derivatives and the formation of a crosslinked (PN)n or (PON)n network. This network enables the formation of a complete, compact, and expanded char residue, effectively isolating heat and oxygen. [ABSTRACT FROM AUTHOR]

Particle boards are manufactured through a hot pressing process using wood materials (natural polymer materials) and adhesive, which find common usage in indoor decorative finishing materials. Flame-retardant particleboard, crucial for fire safety in such applications, undergoes performance analysis that includes assessing temperature distribution across its facing surface and temperature increase on the backside surface during facade combustion, yielding critical insights into fire scenario development. In this study, a compact flame spread apparatus is utilized to examine the flame retardancy and combustion behavior of particle boards, with a specific emphasis on the application of cost-effective flame retardants, encompassing aluminum hypophosphite (ALHP), an intumescent flame retardant (IFR) comprising ammonium polyphosphate (APP), melamine (MEL), and Dipentaerythritol (DPE), alongside magnesium hydroxide (MDH), and their associated combustion characteristics. The D300°C values, representing the vertical distance from the ignition point (IP) to P300°C (the temperature point at 300 °C farthest from IP), are measured using a compact temperature distribution measurement platform. For MDH/PB, APP + MEL + DPE/PB, and ALHP/PB samples, the respective D300°C values of 145.79 mm, 117.81 mm, and 118.57 mm indicate reductions of 11.11%, 28.17%, and 27.71%, compared to the untreated sample's value of 164.02 mm. The particle boards treated with ALHP, IFR, and MDH demonstrated distinct flame-retardant mechanisms. MDH/PB relied on the thermal decomposition of MDH to produce MgO and H2O for flame retardancy, while APP + MEL + DPE/PB achieved flame retardancy through a cross-linked structure with char expansion, polyphosphate, and pyrophosphate during combustion. On the other hand, ALHP/PB attained flame retardancy by reacting with wood materials and adhesives, forming a stable condensed P-N-C structure. This study serves as a performance reference for the production of cost-effective flame-resistant particleboards and offers a practical method for assessing its fire-resistant properties when used as a decorative finishing material on facades in real fire situations. [ABSTRACT FROM AUTHOR]

[Display omitted] • A micro-protective coating was applied to the multi-scale microstructure of wood. • The porous structure of wood is preserved, maintaining its permeability. • Multi-scale micro-coatings provide wood with excellent fire safety properties. • Wood gains antibacterial, photoaging-resistant, and corrosion-resistant properties. • This strategy has been proven reliable, versatile, and durable for various metals. Wood, a naturally renewable material with a porous structure and breathability, rendering it a green construction material that can absorb sound, isolate heat and regulate moisture. Efforts to enhance wood's resistance to combustion while maintaining its porous nature are hindered by the potential impact of physical and chemical treatments on its porous structure, posing a challenge in achieving flame-retardant wood that retains its breathability. Inspired by the multi-layer coating decoration method used on walls of various rooms in frame structure buildings, the study applies multi-scale micro-coating strategy to the multi-scale microstructure of wood. This strategy applied polyamino polyether methylene phosphonate (PAP), metal ions (Al3+/ Mg2+/ Ca2+), and alkali solutions to create a persistent multifunctional protective coating for the multi-scale wood structure. This coating effectively preserved the wood's vessel, ray tissue, cell cavity, and pit structure, protecting its permeability. The modified wood demonstrated an increased limited oxygen value from 19.7 % to 38.4 % and a 55.9 % decrease in the total smoke release compared to natural wood, obtaining high fire safety. Furthermore, the modified wood exhibited adjustable antibacterial, photoaging-resistant and corrosion resistance properties depends on the type of metal. This strategy demonstrated proven reliability, versatility, and durability in the treatment of various metal ions, enabling the production of functional wood with tailored properties. [ABSTRACT FROM AUTHOR]

Decorative veneer, rotary cut from wood, serving as the outermost layer of decorative plates and is exposed to potential risks of fire hazards and bacterial growth. In this study, following the principle of eco-friendly and cost-effective, the polyamino polyether methylene phosphonate (PAPEMP) and magnesium chloride (MgCl 2) were sequentially impregnated into the veneer, and then the alkaline environment was employed to facilitate the complexation, leading to the formation of cross-linked chains within the porous wood structure. Consequently, the modified wood veneer, endowed with exceptional flame retardancy, smoke suppression, antibacterial properties, and good wettability was successfully achieved. Through optimization in an alkaline environment, the modified decorative veneer exhibits a remarkable increase in limiting oxygen index from 19.7% in the pure veneer to 36.9%, coupled with a significant reduction of 19.38% in total heat release and 65.22% in total smoke release compared to the pure veneer. Additionally, the peak mass loss rate (PLMR) of the modified veneer was 66.41% lower than that of the pure veneer, and the char residue increased to 46.1%, representing a 149.19% improvement over the pure veneer. Compared with pure veneer, the wettability of modified veneer increased by 37.93%. Additionally, the tensile strength parallel to the grain of the modified veneer was enhanced by 22.09% compared to the veneer without NaOH solution treatment, and exhibits strong inhibitory effects on colony reproduction. The developed flame-retardant and antibacterial treatment processes for decorative veneers offer a novel and environmentally friendly method for utilizing precious tree veneers, suitable for a variety of precious woods, and successfully applied to decorative wooden doors and wooden fire-resistant doors. [Display omitted] • The precious wood veneer is modified by an efficient flame-retardant system. • The flame-retardant system is convenient, green and environmentally friendly. • Modified veneer offers excellent flame retardant and antibacterial properties. • Modified veneer exhibits significant wettability and mechanical performance. [ABSTRACT FROM AUTHOR]

Synergistic effects of organically modified montmorillonite (OMMT) in combination with different metal oxides (Bi2O3, Sb2O3, and MoO3) on the fire safety enhancement of the intumescent flame‐retarded epoxy resins (EPs) were systematically evaluated. The results from X‐ray diffraction (XRD) and scanning electron microscopy (SEM) analyses show that the OMMT and metal oxides acquire a uniform distribution in the EP matrix, and OMMT platelets exhibit a fully exfoliated state. The flammability and thermogravimetry (TG) tests show that the intumescent flame retardant (IFR)‐OMMT‐metal oxide ternary system can endow EPs with the higher synergistic efficiencies on the enhancement of flame retardancy, smoke suppression properties, and charring ability compared to those of IFR or IFR‐OMMT system, and the synergistic efficiency is the following order: IFR/OMMT/Sb2O3 > IFR/OMMT/MoO3 > IFR/OMMT/Bi2O3. In particular, the sample, filled with 1.5 wt% OMMT, 1.5 wt% Sb2O3, and 27 wt% IFR, passes the UL94 V‐0 rating and acquires the highest limiting oxygen index value of 28.5% among the samples. The IFR‐OMMT‐metal oxide ternary system exerts a better synergistic effect on the generation of crosslinking and aromatic structures that supply the excellent charring effect and barrier effect for the EPs, and the synergistic efficiency of IFR‐OMMT‐metal oxide ternary system is varied with the types of metal oxides. [ABSTRACT FROM AUTHOR]

The combination effect of organically modified montmorillonite (OMMT) and nano‐SiO2 on the fire behavior of intumescent flame‐retarded epoxy resins (EPs) was evaluated. The results from fire tests show that the combination of intumescent flame retardant (IFR), OMMT, and nano‐SiO2 exerts an outstanding synergistic effect on improving the flame retardancy and smoke suppression properties of EPs. For example, the IFR‐3 sample, filled with 27 wt% IFR, 1.5 wt% OMMT, and 1.5 wt% nano‐SiO2, achieves the limiting oxygen index value of 28.2% and passes the UL 94 V‐0 rating, and exhibits a 33.2% reduction in total heat release and 49.3% reduction in total smoke release compared to those of IFR‐0 filled with 30 wt% IFR. Thermo‐gravimetric analysis shows that the combination of IFR, OMMT, and nano‐SiO2 shows a notable improvement in the char‐forming ability of EPs. More importantly, the combination of OMMT and nano‐SiO2 exerts a better synergistic effect on the char‐forming and fire safety of the intumescent flame‐retarded EPs compared to the case of OMMT or nano‐SiO2 alone. This phenomenon is ascribed to the fact that the uniform dispersions of OMMT and nano‐SiO2 particles can facilitate the formation of a more compact and continuous intumescent char against the transmission of heat and combustible gases, thus effectively reducing the fire hazards of the EP composites. Research Highlights: Organically modified montmorillonite (OMMT)/nano‐SiO2 were well dispersed in EP matrix according to X‐ray diffraction and scanning electron microscopy analyses.OMMT/nano‐SiO2 shows a well synergism in reducing the fire hazards of the epoxy resin (EP) composites.Obvious improvement in char‐forming ability is achieved by addition of OMMT/nano‐SiO2.The synergistic mechanism of OMMT/nano‐SiO2 in the EP composites was well proposed. [ABSTRACT FROM AUTHOR]

A novel mono‐component intumescent flame retardant named pentaerythritol phosphate melamine salt (PPMS)‐hybrid bismuth oxide (PPMS‐Bi2O3) was synthesized and carefully characterized by FTIR, 1H NMR, 31P NMR, SEM‐EDS, and TG analyses. Then, PPMS‐Bi2O3 was utilized as flame retardant for epoxy resins (EPs), and the thermal stability, flame retardancy, and smoke suppression properties of EP composites were investigated. TG results show that PPMS‐Bi2O3 is more conducive to enhance the thermal stability and char forming ability of EP composites compared with the same addition of PPMS or the mixture of PPMS and Bi2O3, and this positive effect is enhanced with the increasing Bi2O3 content. Cone calorimeter test reveals that the PPMS‐Bi2O3 can effectively reduce the heat release and smoke production in comparison with PPMS or the mixture of PPMS and Bi2O3 due to the formation of a more compact and intumescent char against fire, as judged by digital photographs and SEM images. EDS analysis indicates that the combination PPMS and Bi2O3 by hydrogen bonds promotes to generate more phosphorus‐rich and aromatization structures in the condensed phase that enhance the barrier effect and anti‐oxidation ability of the char, thus imparting higher flame retardant and smoke suppression efficiencies to EP composites. [ABSTRACT FROM AUTHOR]