Some physico-chemical characteristics of the polyesters obtained using double metal cyanide catalyst

Abstract

High-molecular branched polyethers (PP) on the basis of propylene and ethylene oxides are used as an active base for oil emulsions demulsifying agent compositions. The present investigation focused on the features of the propylene oxide polymerization in the presence of double metal cyanide catalyst on the example of PP based on the mono ethylene glycol and glycerol by varying the molecular weight in the interval 6000–150000. The polymerization was carried out in a laboratory reactor at 110–120 °С, the catalyst concentration from 50 to 300 ppm. For PP samples viscosity, iodine number, molecular-mass characteristics are defined. It is shown that the PP with a molecular weight 6000–40000 are characterized by narrow molecular weight distribution (MWD), a low content of unsaturated impurities. With further increase of the PP molecular weight the broadening of the MWD is observed, the polydispersity reaches a value of 2,5–3,9, which is associated with the formation of low molecular weight unsaturated and bifunctional PP. The results can be used to create the PP technology with using double metal cyanide catalyst.