COPOLYMERIZATION OF TETRAHYDROFURAN AND PROPYLENE OXIDE INITIATED BY FUMING SULFURICPERCHLORIC ACID SYSTEM

<正> Copolymer of tetrahydrofuran （THF） and propylene oxide （PO） of the medium molecular weight （1000—2000） is important in the preparation of polyurethane elastomer, which is characterized by superior properties at low temperature. Such copolyether is usually produced by BF2-diol or BbCl5-diol catalyst system with the following unsolved problems. （ⅰ） The yield is too low, as the PO feed is low. （ⅱ） The m. w. of the product determined by the hydroxyl value method is always higher than by the VPO method, and the calculated functionality is lower than 2, so the composition of the product is compli-