Synthesis of Block Poly(carbonate-ether) Diol via Chain Transfer Copolymerization

Abstract

Polycarbonate polyol is highly desired for making high-performance polyurethanes. This work reports a highly effective synthesis of a block diol with poly(carbonate-ether) and polyether blocks from the partially alternating copolymerization of carbon dioxide (CO2) and propylene oxide (PO), using a zinc-cobalt double metal cyanide complex (Zn-Co DMCC) as the catalyst and poly(propylene ether) diol with a number-average molecular weight (Mn) of 400 g/mol (PPG400) as the chain transfer agent. The Mns of the final block copolymers can be linearly adjusted from 14.4 to 3.3 kg/mol by changing the amount of PPG400. The productivities of the Zn-Co DMCC for producing block copolymer with high CO2 content (ca.60-70 mol%) are 1.80-1.97 kg copolymer/g cat., representing the best record for a heterogenous catalyst for making CO2-based polyols with high CO2 content. This work provides a simple chain transfer copolymerization route to CO2-based diol that is promising to the preparation of packaging cushioning polyurethanes materials.