摘要 |
A process for purifying dipropylene glycol tert-butyl ethers (DPTB) is disclosed. DPTB is made by reacting dipropylene glycol with isobutylene in the presence of an acidic catalyst and the product mixture includes di-tertiary butyl ether impurities derived from dipropylene glycol. The purification process comprises extractive distillation of the product mixture using a glycol extracting agent, preferably dipropylene glycol, which allows removal of di-tert-butyl ether impurities as an overhead product, and then distillation of the DPTB product to separate it from the glycol extracting agent. High-purity DPTB, substantially free of diethers and exceptionally useful as a solvent, is obtained from the process. The process for forming the DPTB and then purifying it is also described. <IMAGE> |