Hierarchically tailored hybrids via interfacial-engineering of self-assembled UiO-66 and prussian blue analogue: Novel strategy to impart epoxy high-efficient fire retardancy and smoke suppression

With the aim of achieving fire safe epoxy (EP), a hierarchical hybrid (UiO66-PDA-PBA) was designed with metal-organic framework (MOF, UiO-66) as the core structure, self-assembled prussian blue analogues (PBA) as surface layers, and polydopamine (PDA) as the link between the two. The tailored hierarchical structure equipped with target functions enabled the enhancement of the intrinsic fire retardancy of the inner UiO-66, through the significant interfacial catalytic effect. The results demonstrated that with the addition on of 3% UiO66-PDA-PBA, EP composites exhibited a 50% decrease in peak heat release rate (pHRR) and a 66% decrease in production of carbon monoxide (COP), accompanied with the suppression of smoke. Meanwhile, the adequate characterizations showed that the interfacial catalyst of nickel species derived from PBA exhibited high activity transforming into residue with a polyaromatic structure and exhibited catalytic oxidation effect for CO through Py-GC-MS and XRD results. The interfacial engineering between this hierarchical fire retardant and polymer may enhance quality of the char residue, which attributed to the ability for efficient catalytic effect, thus enhancing the fire safety of EP. In perspective, constructing the structure tailored hierarchical fire retardants with target functions is an effective means of achieving fire safety in epoxy.