| abstract |
The invention relates to a method for purifying polyalkylene glycols obtained by adding alkylene oxide to alkylene glycol, whereby after addition, the polyalkylene glycol is treated at a pH value of > 7 with a bleaching agent from the group consisting of peroxide, peracids, percarbonates, perborates, peroxide sulfates or oxygen, optionally using a bleach activator. The method is particularly useful for the production of polyethylene glycol with molecular weights ranging from 196 to 203 g/mol, complying with pharmacopoeial requirements. |