Polycarboxylic acid slump retaining agent and preparation method thereof

The invention relates to the technical field of building chemical materials, in particular to a polycarboxylic acid slump retaining agent and a preparation method thereof.The polycarboxylic acid slump retaining agent is prepared by conducting polymerization reaction on unsaturated carboxylic acid, functional monomers and unsaturated polyether macromonomers under the action of an initiator and a molecular weight modifier, the weight-average molecular weight of the prepared slump retaining agent is 20000-25000, and the slump retaining agent is a polycarboxylic acid slump retaining agent. In a low-temperature environment, a main chain of the slump retaining agent is relatively short, many functional groups are exposed outside, and the slump retaining agent is very easy to contact with OH to generate hydrolysis reaction, so that more slump retaining agent molecules exist in a slurry solution and can be further adsorbed to play a dispersion role, and the problem of bleeding caused by concentrated and rapid hyd