METHOD FOR REDUCING AVERAGE MOLECULAR WEIGHT OF COPOLYMERIZED POLYETHER GLYCOL CONTAINING POLYOXYTETRAMETHYLENE GLYCOL OR OXYTETRAMETHYLENE GROUP

摘要

PURPOSE: A method for reducing average molecular weight of copolymerized polyether glycol is provided to exclude the needs on severe conversion of PTMG or PTMG-type polyether glycol to pre-monomer. CONSTITUTION: A method for reducing average molecular weight of PTMG or PTMG-type polyether glycol according to the present invention comprises the steps: a) reacting PTMG or PTMG-type polyether glycol having high molecular weight and perhalobenzoic acid at a temperature of 100 to 250°C for 0.1 to 8 hrs to produce PTMG ester of PTMG-type polyetherglycol ester having a number average molecular weight lower than that of initially charged PTMG or PTMG-type polyether glycol; and b) hydrolyzing or alcohol-added decomposing the said produced PTMG ester of PTMG-typed polyetherglycol ester to obtain PTMG or PTMG-type polyether glycol having low molecular weight.