Polycarboxylate superplasticizers(PCEs)behaved outstanding advantages of low dosage,high dispersibility,and environmental friendliness,etc.have already become the most indispensable component in the preparation of concrete especially(ultra)high strength concrete.However,in practical application they are often accompanied with unexpected problems such as poor compatibility,low water reduction ratio and large slump loss which results from too high content of clay in concrete aggregates.In this paper,through precise design of polymer structures,quasi poly(amino acid)macromolecules(PAAs)were prepared by polymerization of polyether macromonomers(TPEG)and glycidyl methacrylate(GMA),and followed with grafting reaction between its functional epoxy groups and glycine(GA).The polymer structures and its aggregation behavior,water-reducing and dispersing properties of PAAs were investigated by gel chromatography(GPC),dynamic light scattering(DLS),net cement slurries fluidities and concrete experiments.The results show that PAAs exist in the form of aggregates in aqueous solution with a particle size about 30～120 nm,and just the steric hindrance effect of PAAs aggregates could adsorb and disperse cement particles effectively,and also accompanied with preventing competitive intercalation adsorption of clay to PAAs.Therefore,PAAs have excellent water-reducing dispersion and clay insensitivity properties,and thus behave broad application prospects.
关键词
聚羧酸减水剂/类聚氨基酸大分子/自组装/减水分散/抗泥敏感
Key words
polycarboxylate superplasticizers/quasi poly(amino acid)macromolecules/self-assembly/water reducing and dispersion/clay insensitivity
维普
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