A kind of preparation method of ester type highly dispersed high slump retention polycarboxylate water reducer

Abstract

The invention discloses a preparation method of an ester type high-dispersity and high-slump-retaining polycarboxylic acid water reducer. The preparation method comprises the following steps: (1) carrying out esterification reaction; (2) carrying out copolymerization reaction; (3) carrying out neutralization reaction. According to the preparation method disclosed by the invention, unsaturated acidanhydride and polyether diol are esterified to obtain an esterified product containing carboxyl and multi-ester groups; the ester groups in a molecular structure are gradually hydrolyzed under an alkaline condition of cement slurry to release the carboxyl with a water reducing effect, so that the slump-retaining performance is improved; the esterified product with an ester and ether copolymerizedtype side chain, an esterified monomer and isopentenol polyethylene glycol ether are copolymerized to form a polyester and polyether type side chain, a polyester type side chain and a polyether typeside chain which have different lengths; long and short side chains with different types are organically combined, so that the steric hindrance effect can be increased and the initial dispersion performance is improved; the ester type high-dispersity and high-slump-retaining polycarboxylic acid water reducer also has a good slump degree retaining capability and also has a certain air entraining effect.

Description

technical field [0001] The invention belongs to the technical field of building admixtures, and in particular relates to a preparation method of an ester-type highly dispersed and high slump polycarboxylate water reducer. Background technique [0002] In today's world, social economy is developing vigorously, urban construction is advancing by leaps and bounds, followed by the rapid rise of construction related to transportation, water and electricity, municipal administration, etc., the continuous emergence of high-rise buildings and the improvement of construction material construction requirements, the reliability of concrete The requirements for pumpability are getting higher and higher, and high-efficiency water reducers are an essential part of pumping, and polycarboxylate water reducers have become an important part of it. However, for a long time, the use of concrete has been troubled by how to effectively control the slump loss. The pumped concrete produced from th...

AI Technical Summary

Problems solved by technology

However, for a long time, the use of concrete has been plagued by the problem of how to effectively control the slump loss

The pumped concrete produced from the concrete mixing plant often needs long-distance transportation, and the construction environment is different, which will inevitably lead to the loss of concrete slump, which will affect the construction of concrete

Although its slump retention ability can be improved by adding retarders such as sodium gluconate, sucrose or organic phosphate, it cannot fundamentally solve the problem of slump loss

However, most slow-release polycarboxylate superplasticizers have a low initial water-reducing rate and too fast a slow-release speed, which often causes bleeding and segregation in long-distance mixer trucks, causing great difficulties in the construction process.

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