高保坍降黏型聚羧酸减水剂的合成研究

高强度等级混凝土因施工中存在黏度大、流速慢等问题使其发展受到限制.利用聚羧酸高性能减水剂分子的可设计性,引入具有保坍和降黏功能的分子基团,采用不同分子质量的聚醚大单体、丙烯酸、甲基丙烯酸羟乙酯和不饱和功能单体进行自由基共聚常温合成高保坍降黏型聚羧酸减水剂,并探讨了各共聚单体对合成减水剂性能的影响.结果表明,合成高保坍降...

Study on synthesis of polycarboxylate superplasticizer with high slump retention and viscosity reduction

The application of high strength grade concrete is restricted because of its high viscosity and low flow.By making use of the designability of polycarboxylate superplasticizer molecules,the polycarboxylate superplasticizer with high slump retention and viscosity reduction was prepared by grafting molecular groups with slump preservation and viscosity reduction functions.In this paper,the high-slump viscosity-reducing polycarboxylate superplasticizer was prepared by free radical copolymerization of polyether macromonomers with different molecular weight,acrylic acid,hydroxyethyl methacrylate and unsaturated functional monomers,and the effect of each comonomer on the performance of the synthetic water reducing agent was discussed.The results showed that the optimum technological conditions were as follows:acid-ether ratio 3.0,the dosage of AMPS,HEMA and H₂O₂ is 1.6%,1.2%,1.0%of total mass of HPEG respectively.Compared with the same kind of viscosity-reducing polycarboxylate superplasticizer at home and abroad,the synthetic product can significantly reduce the viscosity of high-grade concrete,have better slump-retaining performance in 2 hour,and higher compressive strength in 7 day and 28 day.