摘要 |
The content of cyclic oligomeric ethers in polytetramethylene ether glycols or polyoxybutylene polyoxyalkylene glycols is reduced by a process in which a polytetramethylene ether glycol or polyoxybutylene polyoxyalkylene glycol which contains the said ethers and has a mean molecular weight of from 200 to 450 is mixed with a mixture of water and a hydrocarbon, and, after phase separation, the purified polytetramethylene ether glycol or polyoxybutylene polyoxyalkylene glycol is isolated from the aqueous phase.
|