Patent ID: 7157607

Claim:
A process of manufacture of poly-trimethylene ether glycol comprising; (a) polycondensing reactant comprising diol selected from the group consisting of 1,3-propanediol, 1,3-propanediol dimer and 1,3-propanediol trimer or mixtures thereof in the presence of acid polycondensation catalyst to form polytrimethylene ether glycol; (b) adding water to the polytrimethylene ether glycol to form an aqueous mixture; (c) heating the aqueous mixture to hydrolyze acid esters formed during the acid catalyzed polycondensation; (d) adding to the hydrolyzed aqueous mixture water-immiscible organic solvent that is miscible with polytrimethyl-ene ether glycol to form (i) organic phase containing the poly-trimethylene ether glycol and residual acid polycondensation catalyst from the polycondensing and (ii) aqueous phase; (e) separating the aqueous phase and the organic phase; (f) adding base to the separated organic phase to neutralize the residual acid polycondensation catalyst by forming salts of the residual acid polycondensation catalyst; (g) separating the organic phase into (i) liquid phase comprising the polytrimethylene ether glycol, the organic solvent and any residual water, and (ii) solid phase comprising the salts of the residual acid polycondensation catalyst and the base which is unreacted; and (h) removing the organic solvent and the residual water from the liquid phase to obtain polytrimethylene ether glycol.