Quaternary phosphonium salt and application thereof

Abstract

The invention provides quaternary phosphonium salt with a structural formula shown by formula I. The invention also provides application of the quaternary phosphonium salt as a reaction catalyst for preparing an amide / imide type polycarboxylic acid macromonomer. The quaternary phosphonium salt provided by the invention has the advantages of novel structure, large conjugate area, strong alkalinity (pKa=40-45) and high catalytic activity and applicability; the preparation method is simple and feasible, and a water carrying agent and a polymerization inhibitor are not needed in the reaction process; and moreover, the cost and energy consumption are low, and the method is environment-friendly and clean and has a prospect in industrial application.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, in particular to a quaternary phosphorus salt and its preparation method and application. Background technique [0002] With the development of the high-performance concrete industry, higher requirements are put forward for the performance and production capacity of polycarboxylate superplasticizers. Therefore, it is even more urgent to research and develop polycarboxylate superplasticizers with new structures and characteristic properties. It will increase the market competitiveness of polycarboxylate superplasticizer and expand its application range, which is of great significance to the development of the entire polycarboxylate superplasticizer industry. [0003] Amide / imide polycarboxylate superplasticizer has the characteristics of low dosage, high water reducing rate, good slump retention, excellent dispersion performance, and long storage period. It is classified as the third-generation p...

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Problems solved by technology

[0007] Yet the above method of synthesizing amide macromonomer all has following shortcoming: the one, the by-product of condensation reaction is water, and for promoting reaction, needs to add a large amount of water-carrying agent (toluene, hexanaphthene, benzene etc.), is unfavorable for environmental protection and Sustainable development, and after the reaction, the solvent needs to be distilled off, the process is cumbersome; second, the reaction temperature is relatively high, generally at 110-140 ° C, which is contrary to the low-temperature synthesis process advocated by green building materials; third, at higher temperatures, ( Meth)acrylic monomers are easy to self-polymerize and need to add a polymerization inhibitor, which is not economical and applicable; the fourth is that the preparation and post-treatment process are relatively complicated and difficult to control

[0008] And about the amide / imide compound -CO-NH 2 Or the active hydrogen of -CO-NH-initiates the polymerization reaction of epoxy compound, existing literature and patent report, general catalyst such as alkali metal or alkaline earth metal oxide or hydroxide, DMC, alkyl metal, Lewis acid etc. all Not very effective, only strong base catalysts such as phosphazene base, phosphazene oxide, quaternary phosphonium salt and other inorganic or organic salt catalysts are more effective, and the molecular weight of the produced polyether can reach more than 20,000, with narrow distribution and low degree of unsaturation Low, especially small molecules can be used as initiators, and the end can be capped with ethylene oxide and many other advantages. At present, there is almost no research on it in China. Therefore, the research on this catalyst and its application in alkoxylation technology should be strengthened. It is of great significance and has broad economic and social benefits

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