摘要 |
A method for controlling the molecular weight distribution of polyether glycol in producing polyether glycol having a specified number average molecular weight by polymerizing tetrahydrofuran as a starting monomer with the use of a heteropoly-acid as a catalyst, which method comprises conducting the polymerization in the presence of an amount of water which can form two phases of the organic phase and a catalyst phase, sampling the polymerization product during the polymerization to determine the molecular weight distribution and, when the molecular weight distribution thus found is narrower than the specified molecular weight distribution, making the residence time distribution of the starting monomer in the catalyst phase wider, while, when the found molecular weight distribution is wider than the specified molecular weight distribution, making the residence time distribution of the starting monomer in the catalyst phase narrower.
|