DMC polyether polyols

prepared by the polymerization of propylene oxid with dimetallic catalyot

have been found to suffer obvious degradation and decrease their viscosity and molecular weight during storage. The degradation was found to be influenced by free-radicals

temperature light

and oxygen．However．the degradation can not be stopped by isolation from air and may be eliminated by addition of anti-oxidants．This implies that the degradation is not an stoichiometric oxidation reaction with oxygen in air

but some kind of free-radical induced chain reaction.