Synthesis method of methyl allyl alcohol polyethenoxy ether

Abstract

The invention discloses a synthesis method of methyl allyl alcohol polyethenoxy ether, which comprises the following steps: 1) reacting 5-20 wt% of prescribed methyl allyl alcohol and a catalyst, adding the reaction product into residual prescribed methyl allyl alcohol, and introducing epoxyethane to react, thereby obtaining methyl allyl alcohol polyethenoxy ether low polymer; and 2) reacting 5-20 wt% of prescribed methyl allyl alcohol polyethenoxy ether low polymer obtained in the step 1) and a catalyst, adding the reaction product into residual prescribed methyl allyl alcohol polyethenoxy ether low polymer, and introducing epoxyethane to react, thereby obtaining the methyl allyl alcohol polyethenoxy ether. The methyl allyl alcohol polyethenoxy ether product prepared by the method disclosed by the invention has the advantages of low content of byproducts (polyethyleneglycol and the like), narrow molecular weight distribution, high double-bond protective rate and the like, and is suitable for synthesizing polycarboxylic-acid high-performance water reducing agents.

Description

technical field [0001] The invention relates to a synthesis method of methallyl alcohol polyoxyethylene ether, which belongs to the technical field of synthesis of polyether compounds in organic chemistry. Background technique [0002] Polycarboxylate water reducer has the advantages of high water reducing rate, small slump loss over time, low dosage, low concrete shrinkage, strong controllable molecular structure and environmental friendliness, which can greatly improve the working performance of concrete , greatly improve the compressive strength and durability of concrete, and are widely used in the field of concrete engineering construction such as railways and bridges. There are two ways to synthesize polycarboxylic acid-based water reducers. One is polyether without unsaturated double bonds, such as polyethylene glycol monomethyl ether MPEG. Acrylic acid is reacted to produce methacrylate or acrylate of polyethylene glycol monomethyl ether, and then it is copolymerize...

AI Technical Summary

Problems solved by technology

[0003]The existing synthesis technology of methallyl alcohol polyoxyethylene ether, the US published patent number is US2003199616, and the patent name is: Cement admixture and cement composition. Under the catalysis of sodium hydroxide, methallyl alcohol reacts with ethylene oxide to generate methallyl alcohol polyoxyethylene ether, but it will produce more by-products such as polyethylene glycol, etc., resulting in a decrease in effective content , Molecular weight distribution widens, double bond retention rate decreases, thus affecting its application performance

The patent number is CN 102134313 A, and the patent name is: the preparation method of methallyl alcohol polyoxyethylene ether introduces the methallyl alcohol under the catalysis of sodium methallylate or potassium methallylate and Ethylene oxide reacts to produce methallyl alcohol polyoxyethylene ether. The amount of catalyst is based on methallyl alcohol, which is 0.1~0.6wt%, which can increase the degree of unsaturation of the product by 10%, but the catalyst methyl The preparation conditions and quality of sodium allyl alcoholate and the addition method of catalyst sodium methallyl alcoholate will still affect the quality of methallyl alcohol polyoxyethylene ether, resulting in the generation of by-products such as polyethylene glycol and the broadening of molecular weight distribution , The double bond retention rate is reduced, thereby reducing the application effect of methallyl alcohol polyoxyethylene ether