Polyether Polyols Primary Hydroxyl End Groups Double Metal Cyanide Catalysis

The patent uses a double metal cyanide catalyst as an intermediary substance to enable the polymerization reaction to produce polyether polyols with primary hydroxyl end groups. This catalyst mediates the reaction between the starter compound and epoxide, achieving the desired product structure without requiring complex purification processes. The catalyst works by facilitating the ring-opening polymerization of epoxide monomers while maintaining primary hydroxyl end groups, thus resolving the contradiction between product quality and process complexity.

The patent changes the catalytic parameters from conventional KOH base catalysis to double metal cyanide catalysis. This parameter change fundamentally alters the reaction mechanism, allowing the polymerization to proceed without generating olefinic end groups as secondary products. The double metal cyanide catalyst enables a different reaction pathway that maintains primary hydroxyl end groups while avoiding the formation of unwanted olefinic groups, thus resolving the contradiction between achieving primary hydroxyl content and avoiding harmful byproducts.

The patent employs a double metal cyanide catalyst that can be used in small quantities and does not require extensive purification or neutralization steps. Unlike KOH which requires laborious separation and neutralization, the double metal cyanide catalyst system is designed to be easily removable or deactivatable, significantly reducing the time and complexity of purification steps. This approach treats the catalyst as a disposable or easily removable component, resolving the contradiction between achieving primary hydroxyl content and minimizing purification time.