Polyalkylene oxide catalyst with medium-low molecular weight and preparation method thereof

Abstract

The invention relates to a polyalkylene oxide catalyst with medium-low molecular weight and a preparation method thereof. The catalyst is characterized by being an organic compound of metal calcium, metal strontium and metal barium in a weight ratio of 1 to (0.01-1.7) to (0.01-2) and being prepared by making alkaline earth metal with high purity, anhydrous liquid ammonia, an active agent and a dispersant react in a liquid-phase environment. Compared with the prior art, the catalyst prepared by the method has the advantages of a plurality of activity centers, high low-temperature activity, high aggregation efficiency, stable and controllable aggregation process and short aggregation time. The catalyst of the invention is utilized to prepare a polyethylene glycol oxide product with a medium-low molecular weight at a 0.2-1 million stage and can adjust the molecular weight according to a catalyst prescription. The catalyst of the invention has easily obtained raw materials, simple and convenient preparation, low cost and safe transportation and storage without aging.

Description

technical field [0001] The invention relates to a preparation method of a catalyst for alkylene oxide polymerization. More specifically, it refers to a medium and low molecular weight polyalkylene oxide catalyst and a preparation method thereof. Background technique [0002] Alkylene oxide polymer is a water-soluble polymer with excellent coagulation, dispersion and thickening effects. Because of these excellent effects, alkylene oxide polymers are widely used in pulp dispersants, resin modifiers, binders, coagulants, detergents, food, personal care products, sanitary materials, cosmetics, medical supplies and quasi- in the field of pharmaceuticals. [0003] Starting from metal oxides and their hydrolyzates that can polymerize ethylene oxide and obtain polymers, a series of catalysts for the ring-opening polymerization of alkylene oxides have been developed successively, including the oxidation of alkaline earth metal elements calcium, strontium, and barium. It is an effe...

AI Technical Summary

Problems solved by technology

Chinese patent CN1611523A introduces that during the polymer synthesis process, a compound with active hydrogen is added as a molecular weight regulator to prepare medium and low molecular weight polyethylene oxide, but this method is completed in the polymerization process and has not been improved on the catalyst

U.S. Patent U.S.4200704 describes the purpose of preparing medium and low molecular weight polyethylene oxide by decomposing high molecular weight polyethylene oxide with peroxide in the presence of oxygen, but the process is complicated and the production cost increases

The preparation methods of medium and low molecular weight alkylene oxide polymers involved in the above patents all use secondary processing to achieve the goal, which increases the production process, poor product quality, low economy, and is difficult to control the molecular weight.