Preparation Of Functional CD-MOFs Composite Intumescent Flame Retardant Materials And Fire Safety Performance Study

Intumescent flame retardant materials can effectively improve the fire safety performance of composite materials,curb the spread of fire and reduce the occurrence of major fire accidents.However,traditional intumescent flame retardant coatings still have disadvantages such as poor compatibility and dispersion,which affect the flame retardant efficiency of the coatings.Cyclodextrin-based metal-organic framework materials（CD-MOFs）as organic-inorganic hybrid materials can not only improve the compatibility with the substrate and the thermal stability and flame retardant properties of the materials,but also impart other excellent properties such as adsorption properties.In this thesis,CD-MOFs were firstly prepared and their properties were analyzed.Secondly,CD-MOFs modified aqueous silicone coating was prepared and the effect of CD-MOFs on the combustion behavior and formaldehyde adsorption properties of the coating was investigated.Finally,based on the flame retardant mechanism,two kinds of CD-MOFs composite intumescent flame retardant coatings were prepared and their effects on the flame retardant properties of the coatings were investigated.The progress of the research achieved is as follows:（1）The novel CD-MOFs with regular cubic structure were synthesized by an optimized methanol vapor diffusion method using the green biomaterialγ-cyclodextrin（γ-CD）and alkali metal potassium hydroxide.infrared analysis and X-ray diffraction techniques initially demonstrated the chemical structure of the synthesized materials,and the elemental composition of the synthesized CD-MOFs was confirmed by X-ray photoelectron spectroscopy.the CD-MOFs had a The BET specific surface area of CD-MOFs was 451 cm²-g^-1and showed good thermal stability in the range of 30-600℃.The formaldehyde adsorption rate of 12 g of CD-MOFs reached 95.26%.（2）The effect of CD-MOFs on the fire safety and formaldehyde adsorption of silica-propylene coatings was studied.The degradation process of CD-MOFs-modified silica-propylene coatings and their degradation products in the gas and condensed phases were investigated.the addition of CD-MOFs significantly improved the thermal stability and flame retardancy of the coatings.p-SPR of 12 g CD-MOFs-doped silica-propylene coatings decreased by 35%,TSP by 20.5%,p-HRR decreased by 29.6%,FRI increased by 22%,and the residual carbon was 7.85%at1000℃ with the best flame retardant effect.CD-MOFs increased the activation energy E_αof the coating by 10.4%in the interval from 89 to 229℃.Due to the synergistic effect of the porous structure of CD-MOFs and the hydrogen bonding interaction with the host-guest,14g CD-MOFs made the coating have 82.13%formaldehyde adsorption rate.（3）Ammonium polyphosphate（APP）@CD-MOFs and DOPO@CD-MOFs composites were prepared,and their effects on the fire safety performance of the coatings were comparatively analyzed.the flame retardant and smoke suppression performance of APP@CD-MOFs composite intumescent flame retardant coatings was better than that of DOPO@CD-MOFs,APP@CD-MOFs resulted in a 45.5%decrease in p-SPR,a 32.9%decrease in TSP,a 57.8%decrease in p-HRR,a 3.5-fold increase in FRI,a 59.5%decrease in FGI,and the highest carbon residue rate of 17.5%at 1000℃ for the coating.In summary,the APP@CD-MOFs composite intumescent flame retardant coating prepared in this paper has higher fire safety,and the flame retardant mechanism mainly includes the filling,adsorption and catalytic ablation of metal salts,and the continuous residues formed have a blocking effect,which provides some help and reference for further improving the fire safety of the material and developing functional materials in the future.