Porous and Stable Zn-Series Metal–Organic Frameworks as Efficient Catalysts for Grafting Wood Nanofibers with Polycaprolactone via a Copolymerization Approach

作者：Qifeng Gao, Tanlin Jiang, Weizhou Li, Dengfeng Tan, Xiuhai Zhang, Jinying Pang, Shu‐Hua Zhang · 发表于：Inorganic Chemistry · 年份：2023 · DOI：10.1021/acs.inorgchem.2c03721 · 被引用次数：13 · 研究领域：Metal-Organic Frameworks: Synthesis and Applications、Carbon dioxide utilization in catalysis、biodegradable polymer synthesis and properties

A hydrothermal method was used to synthesize two highly stable Zn(II) metal–organic frameworks (MOFs), namely, [Zn 2 (L) 2 (HIPA)] n ( 1 ) and [Zn 9 (L) 6 (BTEC) 3 (H 2 O) 4 ·6H 2 O] n ( 2 ) (H L = 3-amino-1 H -1,2,4-triazole, H 2 HIPA = 5-hydroxyisophthalic acid, H 4 BTEC = benzene-1,2,4,5-tetracarboxylic acid). The physicochemical properties of 1 and 2 were characterized using a range of analytical techniques. The scanning electron microscopy images confirmed the stability of the MOFs under heating at 120 °C for 12 h. Following their preparation, the two MOFs were used as catalysts in the grafting of poly(ε-caprolactone) on wood nanofibers (WNFs) by means of a homogeneous ring-opening polymerization protocol in an ionic liquid. The grafting ratio achieved using catalyst 1 was higher than that achieved for catalyst 2, wherein a maximum of 92.43% was obtained using the former. Under comparable reaction conditions, the grafting ratio of 1 was found to be significantly higher than those achieved using 4-dimethylamino pyridine, Sn(Oct) 2, and UiO-67 catalysts. In addition, fluorescence emission was detected from the residual catalysts present in the products. The calculated electrostatic potentials and average local ionization energies indicated that the grafting of ε-caprolactone on the WNFs follows a “coordination–insertion” mechanism. Overall, these two new and efficient MOF catalysts have the potential to replace highly toxic traditional catalysts in polymerization reactions...