초록 |
The copolymerization of propylene oxide (PO) with carbon dioxide (CO2) catalyzed by mesoporous double metal cyanide (mDMC) catalysts, prepared by reacting aqueous zinc chloride (II) and potassium hexacyanocobaltate (III) with various complexing agents (CAs) were systematically studied. Compared to existing DMC catalysts, mDMC was synthesized using manganese sulfate (II) and P123 as a template. P123 also acts as a co-complexing agent. The activity and CO2 selectivity of DMC catalysts depend on the types of CAs. The resultant polycarbonate polyols produced in the presence of poly(propylene glycol) (PPG) starter were analyzed by using fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry and hydroxyl value. The hydroxyl functionality of polycarbonate polyols is successfully controlled by the type of PPG starter. |