초록 |
Double-metal cyanide complexes (DMCs) are heterogeneous coordinative catalyst by mixing of K3Co(CN)6 with ZnCl2. It is active in propylene oxide (PO) homopolymerization, but also in PO/CO2 copolymerization. The catalytic performance of DMCs is sensitive to the preparation method and conditions. The preparation of DMC catalysts requires tedious washing processes. In this work, we propose a 100 g scale synthesis of H3Co(CN)6, the structure is determined using X-ray crystallography. DMCs prepared by mixing H3Co(CN)6 and Zn(EH)2 (EH = 2-ethylhexanoate) exhibited good activity in PO homopolymerization even in the presence of a propylene glycol (PG) starter. A conventional DMC was inactive in the presence of such a simple PG starter. The prepared DMC was also active in PO/CO2 copolymerization. However, feeding a starter, such as polypropylene glycol (PPG), to obtain low-molecular-weight macrodiol deteriorated the activity. A substantial amount of cyclic carbonate was generated (~30 wt%). |