Controllable adjustment of loading capacity of Cu-Zr bimetallic MOF on wood substrate to promote flame retardancy
Introducing novel bimetallic metal–organic frameworks (Cu/Zr-MOF) into wood cellulose scaffolds via an in situ growth strategy represents an effective approach to enhance the fire retardancy of wooden products. This work evaluates the effects of Cu/Zr-MOF loading content embedded in wood composite on the MOF morphology and flame retardancy of natural wood (NW). We discovered that MOF loading has a significant impact on the morphology of Cu/Zr-MOF. Specifically, with an increase in the amount of MOF precursors, the morphological transformation is from spherical to regular octahedra. Furthermore, the incorporation of high MOF loading remarkably enhanced the thermal stability at the early stage and exhibited significantly improved residual content. With 24 mass% loading of Cu/Zr bimetallic MOF, the highly flame-retardant wood composite (Cu-U-W-3) was obtained. Compared to pure NW, the peak heat release rate (pHRR) and total heat release (THR) were reduced to 25.25 W g −1 and 5.0 kJ g −1 , respectively. The limiting oxygen index (LOI) of the treated sample reached 24.81%, showing outstanding self-extinguishing ability. According to the char residue analysis, it was found that Cu-Zr bimetallic MOF anchored on the cell wall exhibited catalytic carbon-forming effect, thereby facilitating the generation of high-quality residual char. The enhanced fire safety of natural wood can be attributed to the oxygen barrier and the reduced heat transfer characteristics of the dense carbon layer. This work presents a novel methodology for the fabrication of bimetallic MOF hybrid flame retardants, with the objective of enhancing the flame retardancy of wooden products.
危险品化学品经营许可证（带存储）