The invention discloses a vinyl-terminated hyperbranched
polymer, a
viscosity-reducing type polycarboxylate water
reducing agent with a hyperbranched structure and preparation methods of the vinyl-terminated hyperbranched
polymer and the
viscosity-reducing type polycarboxylate water
reducing agent, and belongs to the technical field of concrete admixtures. The
viscosity-reducing type polycarboxylate water
reducing agent with the hyperbranched structure is composed of the following raw materials in percentage by
mass: 3 to 18 percent of unsaturated
carboxylic acid, 1 to 10 percent of unsaturated anhydride, 0 to 1 percent of unsaturated
phosphate, 75 to 93 percent of unsaturated polyether, 1 to 6 percent of a hyperbranched
functional monomer, 0.1 to 1 percent of an initiator and 0.2 to 3.0 percent of a
chain transfer agent. The prepared water reducing agent has the characteristics of special branched topological molecular structure, low
intrinsic viscosity and the like, effectively weakens the intermolecular chain winding effect of the polycarboxylic
acid water reducing agent, improves the dispersing performance of the water reducing agent, and reduces the dosage of the water reducing agent; and the thickness of an adsorption layer on the surface of a cementing material particle is increased, the thickness of a
solvation layer on the surface of the particle is reduced,
free water is released, and the viscosity of the high-strength concrete is reduced.