Method for synthesizing trimethyl allyl polyoxypropylene ether

Abstract

The invention relates to a method for synthesizing trimethyl allyl polyoxypropylene ether, belonging to the field of alkyl-terminated polyether preparation technologies. The method comprises an alcohol salinization reaction, a terminating reaction and a refining process, namely adding triol polyoxypropylene ether and an alcohol salinization reagent into a reactor, uniformly stirring, then, controlling the temperature and pressure of alcohol salinization, carrying out the alcohol salinization reaction, removing byproducts after the reaction, then, terminating a remaining product, and refining a terminated crude product so as to remove byproducts, thereby obtaining a final product. By adopting the method disclosed by the invention, the phenomenon of the conventional one-step reaction processes that side reactions are increased due to moisture produced during alcohol salinization reaction is avoided, and the problems that secondary hydroxyl polyether is contained, the reaction activity of high-molecular-weight polyether is poor and the termination rate is low are solved.

Description

technical field [0001] The invention relates to a method for synthesizing trimethylallyl polyoxypropylene ether, and belongs to the technical field of preparation of alkyl-terminated polyether. Background technique [0002] The trimethylallyl polyether molecule is the product generated after the triol polyoxypropylene ether is capped with methallyl, and has the following general formula: [0003] [0004] where R can be etc., n is usually a positive integer ≤ 100, [0005] Since the trimethylallyl polyether molecule contains 3 methylallyl groups with high reactivity, it is an ideal crosslinking agent for polymerization, and its molecular structure has good flexibility, so it is very suitable for modification It can be used to prepare reticulated silicones with different characteristics, so that it can be used in a wider range of applications, so it can be used as a building sealant with excellent comprehensive performance. Trimethylallyl polyether products have broad m...

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Problems solved by technology

[0007] 1. The products are mainly polyol allyl ethers with low molecular weight, and the molecules do not contain polyoxyethylene polyoxypropylene ether segments, such as trimethylolpropane allyl ether and trimethylolpropane diallyl ether , Pentaerythritol triallyl ether, etc., are not suitable for methallyl capping of high molecular weight polyethers;

[0008] 2. Phase transfer catalysts, solvents, etc. need to be used in the reaction, and as the reaction progresses, the by-product water produced by the reaction of polyols with sodium hydroxide and potassium hydroxide cannot be removed, side reactions increase, and the end-capping rate decreases, often It is necessary to increase the end-capping agent to increase the end-capping rate, and excessive allyl chloride and sodium (potassium) hydroxide will generate a highly toxic by-product allyl alcohol;

[0009] 3. This method is only suitable for polyols with primary hydroxyl groups at the end, and for molecules containing polyoxypropylene ethers, because the ends are secondary hydroxyl groups with poor reactivity, the secondary hydroxyl groups cannot be polyoxypropylene ethers in this way. Synthesis of products

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