采用原位生长策略成功制备了一系列新型金属-有机骨架@轻木气凝胶[MOF@WA,MOF=UiO-66,MIL-53(Al)和ZIF-8]复合材料,系统地分析研究了其微观组织结构及阻燃性能。结果表明,将三种不同的MOF引入WA基体骨架后,MOF颗粒均匀分布在WA内部管腔表面并保持了高结晶度。相比于UiO-66@WA和ZIF-8@WA,MIL-53(Al)@WA表现出更为优异的热稳定性和阻燃性能,其中残炭率提升了25.4%,极限氧指数(LOI)从28.9%增加到32.4%;热释放峰值(pHRR)从UiO-66@WA和ZIF-8@WA的97.2W/g和130W/g急剧降低至18.3W/g,总热释放量(THR)则从7.5kJ/g和8.4kJ/g降低至1.4kJ/g。燃烧后的残炭结构分析显示,MOF的引入促使其金属组分转化为金属氧化物并表现出一定的催化成炭效应,从而促进了致密炭层的形成。这一屏障有效抑制了易燃挥发物和热量的传递,其中MIL-53(Al)的成炭效果最为显著。本研究提出了一种新颖的MOF复合阻燃剂的制备方法,旨在提高木材衍生材料的阻燃性能。

In this study,we successful synthesized a series of novel metal-organic framework@balsa wood aerogel composites (MOF@WA,MOF=UiO-66,MIL-53(Al),and ZIF-8) through an in-situ growth approach,coupled with a comprehensive analysis of their microstructural characteristics and flame-retardant properties.The results indicated that after introducing three distinct MOFs into the WA matrix,MOF particles uniformly distributed on the inner lumen surfaces of WA,while maintaining high crystallinity.Compared to UiO-66@WA and ZIF-8@WA,the MIL-53(Al)@WA composite showed enhanced thermal stability and flame-retardant performance,as demonstrated by a 25.4% increase in residual char yield and an elevation of the limiting oxygen index (LOI) from 28.9% to 32.4%.Additionally,its peak heat release rate (pHRR) sharply declined from 97.2W/g(UiO-66@WA) and 130W/g(ZIF-8@WA) to 18.3W/g,with the total heat release(THR) decreasing from 7.5kJ/g and 8.4kJ/g to 1.4kJ/g.Post-combustion char analysis revealed that MOF incorporation facilitated the transformation of metal constituents into metal oxides,inducing a catalytic charring effect that promoted the formation of a compact char layer.This barrier efficiently inhibited the transfer of flammable volatiles and heat,with MIL-53(Al) demonstrating the highest charring efficacy.This work presented an innovative approach for developing MOF-based nanocomposite flame retardants,aiming to enhance the flame retardant properties of wood-derived materials.