Synthesis of polycarbonate diols catalyzed by calcined hydrotalcites doped with the transition metal Ni2+
Abstract
Calcined hydrotalcites doped with Ni2+ (HTC-Ni-T) were prepared and used as catalysts for the synthesis of polycarbonate diols (PCDLs) via transesterification between dimethyl carbonate (DMC) and 1,4-butanediol (BDO). The effects of the content of doped Ni2+ and calcination temperature of HTC-Ni-T on the BDO conversion were investigated. The results showed that the catalytic activity is positively correlated with the content of doped Ni2+ (0.1–0.7 mmol g−1 HT) and calcination temperature (573–773 K), and is determined by the basicity and the structure of the catalyst. HTC-Ni with a Ni2+ doping content of 0.7 mmol g−1 HT calcined at 773 K exhibited the maximum activity. Based on this, the effects of reaction conditions on the conversion of BDO and the yield of PCDLs were studied. Under optimal reaction conditions, the conversion of BDO can reach 80.9% for the transesterification and the yield of PCDLs with an Mw of 1880 can reach 95% for the polycondensation. Moreover, the catalyst was reused four times without a significant loss of the catalytic activity.