256results about How to "Shorten spin time" patented technology

The invention discloses a method for preparing polyether polyol in a recycling manner by the aid of a DMC (double metal cyanide) catalyst. The method includes carrying out polymerization reaction on first low-molecule alcohol and alkylene oxide to obtain polymers with low molecular weights; carrying out reaction on the polymers with the low molecular weights, DMC, acid and alkylene oxide, simultaneously filling the polymers with the low molecular weights with a certain quantity of second low-molecule alcohol used as a raw material to obtain intermediate target polymers; preparing target polymers from a part of the obtained intermediate target polymers and preparing other intermediate target polymers from another part of the obtained intermediate target polymers in a recycling manner. The first low-molecule alcohol is used as a raw material. The polymers with the low molecular weights are used as initiators, the DMC is used as the catalyst, and the acid is used as an auxiliary. The average molecular weight of the intermediate target polymers is identical to the average molecular weight of the polymers with the low molecular weights. The method has the advantages that the polyether polyol can be prepared by the aid of the method in the recycling manner without alkali manufacturing initiators, and accordingly loss of materials and discharge of filter residues and wastewater can be reduced; the DMC catalyst in reaction systems for initial reaction is already activated under the condition that the concentration of the DMC in the target polymers keeps identical, accordingly, the dehydration time and the initiation time can be shortened to a great extent in production procedures, and the utilization efficiency of devices can be improved.