Catalytic behavior of a ZnO/TiO2 composite in the synthesis of polycarbonate diol

Abstract

ZnO/TiO₂ catalysts with different ZnO contents have been prepared through equal volume impregnation method, characterized by XRD, SEM, Py-IR, ICP, XPS, NH₃-TPD and N₂ adsorption/desorption, and evaluated in the synthesis of polycarbonate diol (PCDL) through transesterification. The results showed that titanium zinc oxide formed in these catalysts, and the content of acidic sites varied with the ZnO content, and ZnO/TiO₂ (10%) has the highest acid amount. The ZnO/TiO₂ (20%) with medium acidic sites showed the highest catalytic activity. The synthesis process of polycarbonate glycol was also optimized. Under the optimal reaction conditions, the yield of PCDL was 72.5%, and the M_n reached 4829 g mol⁻¹ with a PDI of 1.6.