POLYTETRAMETHYLENE ETHER GLYCOL WITH REDUCED AMOUNT OF CYCLIC OLIGOMER AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To obtain a polytetramethylene ether glycol(PTMG) having a reduced amount of cyclic oligomers of tetrahydorfuran(THF) dodecamer to eicosamer, and to provide a method for manufacturing the same. SOLUTION: The polytetramethylene ether glocyl having a reduced amount of cyclic oligomers has a sum of ring compounds of tetrahydrofuran dodecamer to eicosamer, measured by matrix support laser desorption mass spectromertry, of >=20%. The method for manufacturing the polytetramethylene ether glycol having a reduced amount of cyclic oligomers by subjecting tetrahydro-furan to ring opening polymerizationin the presence of an acid catalyst and acetic anhydride to obtain a polytetramethylene glycol acetic acid diester, and then transesterifying this acetic acid diester with a lower alcohol comprises conducting the ring opening polymerization reaction at 40 deg.C or below.