Synthesis of Polycarbonate Diol Catalyzed by Metal-organic Framework Based on Zn2+ and Terephthalic Acid

Metal-organic framework based on Zn2+ and terephthalic acid (TPA) was prepared and characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. It was then used as the catalyst for the transesterification between diphenyl carbonate (DPC) and 1, 6-hexandiol (1,6-HD) to polycarbonate diol (PCDL). Compared to Mg-Al layered double hydroxide, triethylenediamine, sodium ethoxide and sodium methoxide, it exhibits the highest catalytic activity for the synthesis of PCDL. Under optimal reaction conditions(n(1,6-HD)/n(DPC) = 1.2, w(catalyst) = 0.03%, 198 degrees C), the yield of phenol is up to 90.1% in the transesterification process, and PCDL with higher M-n and lower hydroxyl value can be synthesized.