Preparation method and application of a straw-based ester ether sulfonated composite water reducer

Abstract

The invention discloses a preparation method and application of a straw-modified ester ether sulfonated composite water-reducer. The water-reducer is made from crop straw hydrolyzed powder through primary oxidation-sulfonated esterification of straw lignocellulose Modification, secondary oxidation-sulfonated esterification modification and primary methylolation-etherification modification. The straw hydrolyzed powder is obtained by hydrolyzing the straw powder after primary crushing, washing, drying, finely crushing and finely crushing pretreatment of crop straw. In the present invention, the raw materials of crop straws are pulverized and hydrolyzed for pretreatment, and straw lignin and cellulose are subjected to step-by-step sulfonation modification to form sulfonate esters, and then lignocellulose etherification modification is carried out to obtain straw-based ester ethers. The sulfonated composite water reducer has improved the low water reducing rate of 10-15% of the straw-based water reducer, and the obtained water reducer can be directly used in the situation where the water reducing rate is about 25% and the retarding time is moderate , the process is continuous and compact, easy to operate, low in cost, anti-sedimentation and easy to industrialize.

Description

technical field [0001] The invention relates to the preparation of a biomass-based water reducer by modifying crop straws, in particular to a preparation method and application of an ester ether sulfonated composite water reducer based on straw modification. Background technique [0002] At present, with the increasing shortage of petrochemical raw materials required for the preparation of a new generation of high-performance petroleum-based polycarboxylate water reducers for concrete admixtures, the outstanding problem of rising prices has restricted the new generation of high-performance polycarboxylate water reducers. The rapid development of additives has led to rising production costs, making polycarboxylate superplasticizers that have higher performance advantages than naphthalene-based, aliphatic-based, sulfamate-based, and lignin-based water-reducing agents unable to be used in the market. The vigorous promotion and application of the construction industry. Scholars...

AI Technical Summary

Problems solved by technology

The water reducing agent prepared by this method has a low water reducing rate and can only be used as the most common water reducing agent

Chinese patent CN 101759856 B "Preparation method of sodium lignin sulfonate water reducer", using corn cob, corn cob acid hydrolysis residue, bagasse or corn stalks as raw materials through alkali boiling black liquor, after coarse filtration, ultrafiltration Membrane concentration, sulfonation and spray drying to prepare sodium lignosulfonate superplasticizer with low water content. This process has no pollution to the environment, simple process and low cost, but straw raw materials cannot be fully utilized and the waste is serious

However, the results of these two studies are just laboratory shake-flask experiments. One is that the degree and method of crushing the straw are not proposed, only the straw is crushed. Bringing in excess chloride ions and sulfate ions will affect the performance of the water reducer. Third, there is no idea and idea for industrial testing, and there is still a long way to go before industrialization.

Images