Preparation method of modified natural chitin polymer sodium phosphate cathode rust inhibitor

Abstract

The invention relates to a preparation method of a modified natural chitin polymer sodium phosphate cathode rust inhibitor, which starts from molecular design and dominant functional group theory of acathode steel bar rust inhibitor and uses natural chitin, sodium hydrogen phosphite and formaldehyde as raw materials. Firstly, a natural chitin polymer undergoes deacylation reaction under the condition of a compound strong alkali to prepare a chitosan polymer containing amino group; then under the action of a strong oxidant and a composite catalyst, the macromolecular chitosan containing the amino group is degraded into low molecular weight chitosan; finally, under acidic conditions, the low molecular weight chitosan, sodium hydrogen phosphite and formaldehyde undergo condensation reactionto prepare a novel modified natural chitin polymer sodium phosphate cathode rust inhibitor containing CH2OH, -OH and -PO3 groups. The preparation of the modified natural chitin polymer sodium phosphate cathode rust inhibitor widens the application field of natural chitin polymer materials and reduces the cost of raw materials in the preparation process of the cathode rust inhibitor.

Description

technical field [0001] The invention relates to the technical field of building materials, in particular to a preparation method of a modified natural chitin polymer sodium phosphate cathode rust inhibitor. Background technique [0002] As a widely used civil engineering material, reinforced concrete has been widely used in the construction of large buildings, viaducts, embankments, subsea tunnels, cross-sea bridges, deep-sea port terminals and offshore oil platforms. For reinforced concrete, the pH value of hardened concrete is 12-13, and in a strongly alkaline state, an alkaline oxide film is formed on the surface of the steel bar, which is firmly adsorbed on the surface of the steel bar, making the steel bar in a passivated state and free from corrosion. But for reinforced concrete structures in the environment, chloride ions in the environment can easily penetrate into the steel surface, and OH - Competitive adsorption on the surface of steel bars leads to shrinkage and...

AI Technical Summary

Problems solved by technology

At the same time, the raw materials for the preparation of traditional imidazole, pyrimidine, pyridine and other five- or six-membered heterocyclic alcohol ammonia-based cathodic rust inhibitors are mostly artificially synthesized chemicals, which have limited sources, expensive prices, complex preparation processes, and production processes that are harmful to the surrounding environment. and highly toxic exhaust gases harmful to health

These shortcomings have hindered the widespread application of traditional alcohol ammonia cathodic rust inhibitors in reinforced concrete structures.

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