In this study,2,3,5,6-tetrafluoro-bis (1,2,4-triazole-1-methyl) benzene (Fbtx) and 4,5-dichloro phthalic acid (H2dcpa) were selected as ligands,and reacted with cobalt acetate through hydrothermal method to obtain a new cobalt-based metal organic framework material [Co(Hdcpa)2(Fbtx)2]n (Co-MOF).The Co-MOF was structurally characterized by X-ray single-crystal and powder diffraction technologies,infrared spectroscopy,and other characterization methods.The crystal structure analysis showed that Co-MOF had a two-dimensional layered structure.The thermal stability of the Co-MOF was examined by thermogravimetric analysis,and the results revealed that its framework remained stable up to 300℃,implying good thermal stability.On the basis of PLA,ammonium polyphosphate (APP) and Co-MOF,a series of PLA/APP/Co-MOF composite materials were prepared by melt blending method,and the effect of addition amount of APP and Co-MOF on the flame-retardant performance was investigated in detail.The results indicated that the composite material had better flame-retardant performance when the addition amounts of APP and Co-MOF were 13.5wt% and 1.5wt%,respectively,in which the LOI value was 36.0%,and UL-94 could reach up to the V-0 level while the droplet phenomenon of the PLA sample was suppressed.Meanwhile,the results of conical calorimetry tests showed that a continuous and dense carbon layer was formed during the combustion process of PLA/APP/Co-MOF,and the PHRR and THR values reduced by 55.7% and 48.5%,respectively,thus effectively controlling the smoke release.
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基金资助
国家自然科学基金(21676030)
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