Preparation method of isopentenol polyoxyethylene ether

Abstract

The invention discloses a preparation method of isopentenol polyoxyethylene ether. The method comprises the steps of: 1) firstly reacting 5-20wt% of prescribed dosage isopentenol with a catalyst, then putting the product into the remaining prescribed dosage isoprene, and introducing ethylene oxide to react so as to obtain an isopentenol polyoxyethylene ether oligomer with a molecular weight of 300-500; 2) reacting the prepared 5-20wt% of prescribed dosage isopentenol polyoxyethylene ether oligomer with the catalyst, then putting the product into the remaining prescribed dosage isopentenol polyoxyethylene ether oligomer, and introducing ethylene oxide to react so as to obtain isopentenol polyoxyethylene ether with a molecular weight of 500-5000. The product prepared by the invention has the advantages of low content of polyethylene glycol and other by-products, narrow molecular weight distribution, and high double bond protection rate, and is suitable for synthesis of polycarboxylate type high performance water reducing agents.

Description

technical field [0001] The invention relates to a preparation method of prenol 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 copolymerized with mo...

AI Technical Summary

Problems solved by technology

[0003] Existing synthesis technology about prenyl alcohol polyoxyethylene ether, China's published patent number is CN101928392A, patent name is: a kind of synthetic method of prenyl alcohol polyoxyethylene ether, introduces prenyl alcohol polyoxyethylene ether in solid methanol Sodium, sodium methoxide methanol solution, potassium hydroxide solid or aqueous solution, sodium hydroxide or aqueous solution, sodium, sodium isoenolate or a mixture of one or more of them react with ethylene oxide to form isopentene Alcohol polyoxyethylene ether, but for solid sodium methoxide and sodium methoxide methanol solution, more by-products such as polyethylene glycol monomethyl ether, etc. will be produced, and the effective content will be reduced, the molecular weight distribution will be broadened, and the double bond retention rate will be reduced. , thereby affecting its application performance; and for potassium hydroxide solid or aqueous solution, sodium hydroxide solid or aqueous solution, more by-products such as polyethylene glycol will be produced, and at the same time, it will lead to a decrease in effective content, a broadening of molecular weight distribution, and double bond retention rate decreases, thereby affecting its application performance; and for sodium and iso-sodium enolate, the preparation conditions and quality of the catalyst sodium prenolate and the addition method of catalyst sodium and sodium prenolate will still affect the prenolate. The quality of polyoxyethylene ether leads to the generation of by-products such as polyethylene glycol, the broadening of molecular weight distribution, and the reduction of double bond retention, thereby reducing the application effect of isopentenol polyoxyethylene ether