Polyether graft poly-carboxylic acid concrete water reducer preparation

Abstract

Production of polyether graft poly-carboxylic acid concrete water reducer is prepared by sulfonating styrene-anhydride multipolymer with anhydride content 10í½50 mol% and relative molecular mass 2000í½20000 from sulfonating agent of non-destructive acid anhydride group, esterifying grafting polyether side chain on acid anhydride key, and dissolving in water. Its advantages include simple process, no catalyst, higher fluidity of cement concrete and compression strength.

Description

technical field [0001] The invention relates to a preparation method of polyether grafted polycarboxylic acid concrete water reducing agent. Background technique [0002] The water reducing agent is used in concrete, which can reduce the water required for cement hardening, has a strong dispersion effect on cement, makes the physical structure of concrete more uniform after solidification, and improves the strength of concrete. According to the water reducing effect, the water reducing agent includes ordinary water reducing agent and high efficiency water reducing agent. Ordinary water reducing agents such as sodium rosinate, lignin sulfonate, stearic acid soap and other organic substances have a low water reducing rate, generally around 10%, which can only improve the strength of concrete to a limited extent, and are generally only used for concrete with low strength requirements middle. In order to meet the increasingly complex and large-scale requirements of concrete en...

AI Technical Summary

Problems solved by technology

At present, representative high-efficiency water reducers include melamine formaldehyde condensate and naphthalenesulfonate formaldehyde condensate. The former has limited application due to its high production cost; the latter has low production cost and is widely used, but due to its low water reducing rate High, and has the disadvantage of rapid loss of concrete slump

Both of the above two high-efficiency water reducers use volatile and toxic formaldehyde in the preparation process, which inevitably causes environmental pollution and is not conducive to sustainable development

Modified waste polystyrene is used as a high-efficiency water reducer. Although it has high environmental protection value, it is easily restricted by the source of raw materials, and the water reduction rate is generally lower than 30%.

At the end of the 1980s, Japan researched and developed a sulfamic acid-based water reducer with a single-ring aromatic structure. This is a non-air-entraining water-soluble resin with a water-reducing rate of up to 30%. The sag loss is small, but the product stability is poor, and it is easy to bleed when the dosage is too large, thus affecting the industrial production and application of the water reducer

The above synthetic methods are to first prepare a macromonomer with polymerization activity (usually methoxy polyethylene glycol methacrylate), and then mix a certain proportion of monomers together to directly adopt solution polymerization to obtain the finished product. The premise of the synthesis process is to synthesize a macromolecular monomer, which is difficult to synthesize, and the intermediate separation and purification process is relatively complicated. The raw material of the synthesized macromolecular monomer is unstable, difficult to store, unable to be marketed, and the cost of industrialization is relatively high