Bin Li,Wubin Wu,Tianyong Zhang,Shuang Jiang,Xingwei Chen,Guanghui Zhang,Xia Zhang
UiO-66 with high dispersibility and a cuboctahedron morphology was synthesized by an improved solvothermal method. The morphology of UiO-66 was adjusted using benzoic acid as a modulator. UiO-66 with a regular morphology was then used as the support to load ferrocene (Fc). A series of Fc@UiO-66 composites were prepared via a facile impregnation method. The composites were characterized by powder X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), SEM/EDX mapping, FT-IR, UV/vis, TG analysis, N2 adsorption–desorption, and X-ray photoelectron spectroscopy (XPS). The results showed that Fc was incorporated into UiO-66, thus preventing the agglomeration of Fc particles in water. The Fc@UiO-66 composites with a Fc loading of 5% (FU-5) exhibited the highest catalytic activity for hydroxylation of phenol with H2O2 at room temperature in water, which gave a phenol conversion of 38.5% and 87.4% selectivity for dihydroxybenzenes (DHB). UiO-66 played a crucial role in the enhancement of catalytic performance compared with conventional supports such as γ-Al2O3, etc. A hydroxyl radical mechanism was proposed for this catalytic hydroxylation process and the high selectivity was attributed to the interaction between Fc particles and UiO-66.
In this paper, we report on the synthesis of a new aluminum bis(hydroxy-phenyl-methyl)phosphinate, AlBPi, under mild reaction conditions. The product structure was confirmed via characterization, and its thermal stability and flame retardant properties were assessed. To improve the flame retardant properties, we employed ammonium polyphosphate (APP) as a synergist with AlBPi. The PLA composite material containing 10% AlBPi and 5% APP achieved an LOI of 28.1% and a UL-94 rating of V-1. Cone calorimetry tests showed a significant reduction in PHRR, THR, PSPR, and TSP for the PLA/AlBPi/APP composite compared to the pure and PLA/AlBPi materials. SEM analysis revealed a continuous and dense char layer on the residual surface of the synergistic flame retardant sample. AlBPi and APP exhibited excellent synergistic flame retardant effects, with both releasing a large amount of PO·free radicals. APP was also able to release inert gas, exhibiting excellent flame retardant effects in the gas phase. Additionally, APP improved the charring performance of AlBPi and formed a compact char layer on the material surface, achieving good flame retardant effects in the condensed phase. Therefore, the AlBPi and APP synergistic flame retardant system can be considered a viable flame retardant additive for PLA. Highlights A novel flame retardant AlBPi was synthesized. AlBPi and APP demonstrate good synergistic flame retardant performance in PLA. AlBPi and APP play a flame retardant role in both gas and condensed phases.
危险品化学品经营许可证（带存储）