Polymer having dispersing function, polycarboxylic acid cement dispersant, preparation method therefor and use thereof

A polycarboxylic acid cement dispersant having a thickening index not more than 1.5 at a temperature of 120° C. or more;

• a 24 h compressive strength index not less than 0.8 at a temperature of 110° C.;
• a consistency coefficient not more than 0.8 at a temperature of 85° C.;
• and a liquidity index n not less than 0.6 at a temperature of 85° C.

A method for preparing a polycarboxylic acid cement dispersant, the method comprising:

• subjecting a monomer mixture to a polymerization reaction in water under the solution polymerization conditions in the presence of an initiator, wherein the monomer mixture comprises a monomer-A which is an unsaturated polyether, a monomer-B which is an unsaturated acid and/or a salt thereof and/or an anhydride thereof, and a monomer-C which is a silane and/or siloxane comprising a polymerizable group and having no less than five carbon atoms;
• and the molar ratio of the monomer-A, the monomer-B and the monomer-C in the monomer mixture is 1:(1-20):(0.01-0.5);
• the polymerization conditions cause that the obtained polymer has a weight average molecular weight of 20,000-90,000.

(canceled)

(canceled)