Preparation method for methyl alkenyl polyoxyethylene polyoxypropylene ether with high polymerization degree and macromonomer

Abstract

The invention discloses a preparation method for methyl alkenyl polyoxyethylene polyoxypropylene ether with high polymerization degree and macromonomer. The preparation method includes the following steps: 1) utilizing methyl alkenyl alcohol as a starting agent, adding ethylene oxide in the presence of a basic catalyst to carry out a condensation reaction, and performing curing at a maintained temperature after full introduction to obtain a methyl alkenyl alcohol polyoxyethylene ether oligomer; 2) adding the basic catalyst to the oligomer obtained in the step 1), adding propylene oxide for performing the condensation reaction, and performing the curing at the maintained temperature after the full introduction; and 3) continuing to introduce the ethylene oxide in a reactor for performing the condensation reaction until no pressure in the reactor, and then adding acetic acids for performing neutralization to obtain methyl alkenyl alcohol polyoxyethylene polyoxypropylene ether. Synthesisof the methyl alkenyl polyoxyethylene polyoxypropylene ether with the high degree of polymerization and the macromonomer is performed in two steps, the mass growth ratio is up to 1:100, a product is high in degree of polymerization and is high in reactivity, and a synthetic polycarboxylate-type water reducing agent is excellent in slump loss resistant property and comprehensive performance.

Description

technical field [0001] The invention belongs to the technical field of organic chemistry, and in particular relates to a method for preparing a high degree of polymerization macromonomer methylalkenyl polyoxyethylene polyoxypropylene ether. Background technique [0002] In recent years, my country's national economy has grown rapidly, and the construction industry has continued to develop rapidly. The construction of major projects such as high-speed railways, highways, airports, bridges and tunnels, hydropower, seaports and wharves has a great impact on high-performance concrete, self-compacting concrete, high-flow The demand for permanent concrete is increasing, the quality requirements are getting higher and higher, and the workability requirements for concrete mixtures are also comprehensive and diversified, such as high fluidity, low slump loss, no bleeding and no segregation, Good pumpability. [0003] After years of development, the water reducer products have gone thr...

AI Technical Summary

Problems solved by technology

Due to the reactive structural characteristics of the methyl alkenyl alcohol polyether macromonomer and the trace moisture in the raw materials that are not easily removed during production, PEG is easy to form; the macromonomer is also prone to rearrangement reactions during synthesis, resulting in "internal "ene" and other impurities; in the production of block and random polyether, the chain transfer rearrangement reaction of propylene oxide also causes low molecular weight and wide molecular weight distribution

These factors make it difficult to increase the molecular weight and high impurity content in the synthesis of high-polymerization polyether macromonomers, resulting in its performance not meeting the polymerization requirements of polycarboxylate superplasticizers.