新型聚羧酸系高效减水剂的合成及性能研究

结合高分子科学及混凝土科学的“分子设计”原理,将丁氧基聚氧乙烯甲基丙烯酸酯（BPEOMA）、AA、MAA、不饱和磺酸盐单体通过自由基水溶液共聚合的方法合成了一种新型梳状聚羧酸系高效减水剂SP,通过傅立叶变换红外光谱表征了减水剂的分子结构.重点研究了磺酸盐种类、用量,不饱和羧酸及引发剂对减水剂性能的影响.结果表明,减水剂SP具有良好的分散性及分散保持性能,折固掺量为0.3%,水灰比为0.29时,水泥净浆流动度可达290mm,90min内坍落度基本不变,且无泌水现象.

Preparation and properties of a novel polycarboxylic superplasticizer

Based on the molecular design theory of polymer and concrete science, a novel comblike high-performance water reducing agent(superplasticizer) SP with anionic groups and nonionic butylpolyethylene oxide (BPEO) side chain for concrete was prepared through free radical solution copolymerization. The structure of copolymer was characterized by FTIR. The influences of sulfonic groups, carboxylic groups, and initiator on dispersing properties were discussed in details. Results indicate that SP exhibits excellent dispersity and fluidity retention ability to cement grout. The fluidity of cement grout can reach as high as 290 mm at the neat copolymer usage of 0.3wt%, water-cement ratio 0.29 and no slump loss occurs within 90 minutes.