Synthesis Of Polycarboxylic Series Of High Performance Water Reducer

The polycarboxylic series of water-reducing agent was characteristic of high water-reducing ratio and preventing concrete mix from slump loss with duration of time. Nowadays, it has become the modern frontier research of high performance water reducer.Based on the key group theory, the chemical configuration and working principle of high performance water reducer, a comb-like copolymer structure of polycarboxylic type water reducer with carboxylic group-ether link-sulphonic link was modified and synthesized in this thesis. The synthesis and performance of the polycarboxylic series of dispersant are both discussed in this paper.The best experimental conditions and mixing proportion to synthesized methyl acrylate with different polymerization of polyoxyethylene side chain groups were determined. Based on the conditions, a comb-like polycarboxylic series of superplasticizer was synthesized with the methyl acrylate and other monomer. By way of orthogonal testing analysis, study was carried out on effects of molar ratio on unsaturated monomers with carboxylic groups, sulphonic groups, polyoxyethylene side chain groups and different usage of initiator on performance of polycarboxylic series of water reducer. Different optimum formulas for synthesizing polycarboxylic series of high performance superplasticizer with different polyoxyethylene side chains were proposed. Through the study of IR spectrum and chemical test, it was proved that polycarboxylate-type superplasticizer can be synthesized in the aqueous system by tri-copolymerization of vinyl monomers with carboxylic groups, sulphonic groups, polyoxyethylene side chain groups.Comparing with other kinds of high performance water-reducing agent, the concrete experimental results showed that SP23 has the advantages of high water-reducing ratio, good slump-loss resistant property and strength enhancement.