Solid flaky polycarboxylate slump retaining agent prepared by surfactant-free emulsion polymerization and method

Abstract

The invention provides a solid flaky polycarboxylate slump retaining agent prepared by surfactant-free emulsion polymerization and a method. The solid flaky polycarboxylate slump retaining agent is prepared from the following components in parts by weight: 18-27 parts of a surfactant-free emulsion ester-based hydrophobic monomer, 0.48-0.72 parts of an initiator a, 9-18 parts of a surfactant-free hydrophilic small monomer, 0.41-0.69 parts of a chain transfer agent a, 765-810 parts of a polyether macromonomer, 32-68 parts of unsaturated dicarboxylic acid, 12-28 parts of an unsaturated sulfonic small monomer, 50-74 parts of alkyl acrylate, 2.3-3.8 parts of a chain transfer agent b, 3.2-5.9 parts of an initiator b, 2.6-4.6 parts of an initiator c, 3.2-4.7 parts of a chain transfer agent c, and7.7-11.5 parts of a pH regulator. The method comprises the following operation steps: (1) preparing a surfactant-free polymer; (2) preparing solutions A, B and C; (3) dropwise adding the solutions A,B and C; and (4) preparing the solid flaky polycarboxylate slump retaining agent. The slump retaining agent can effectively slow down cement hydration, effectively keep concrete slump for a long time, slow down the time-dependent loss of the concrete slump and keep the fluidity and workability of concrete, and the properties in all aspects are more stable.

Description

technical field [0001] The invention relates to the technical field of building materials and polycarboxylic acid slump-retaining agents, in particular to a solid-chip polycarboxylate slump-retaining agent prepared by a soap-free emulsion method and a method thereof. Background technique [0002] As the fifth component of modern concrete, polycarboxylate superplasticizer has been widely used in the field of concrete engineering technology due to its excellent low dosage, high slump performance, and large degree of freedom in molecular design. At present, most widely used polycarboxylate slump-retaining agents are solution products with a concentration of 10-50%. Due to the remote distance of some construction sites, the lower solid content will increase the transportation cost; in addition, the wide application of dry powder mortar also puts forward an urgent demand for the production and application of solid polycarboxylate slump-retaining agents. When using slump retainin...

AI Technical Summary

Problems solved by technology

[0008] The object of the present invention is to provide a kind of solid sheet polycarboxylate slump-retaining agent and method prepared by soap-free emulsion method, solve the problem of prior art that slump-retaining agent can not slow down cement hydration for a long time, is not suitable for high temperature and dry environment

Images