摘要
将柠檬酸作为侧基引入到聚羧酸大分子链中,合成了一种新型聚羧酸系高效减水剂.制备条件为:n(丙烯酸聚乙二醇酯)∶n(马来酸聚乙二醇柠檬酸酯)∶n(丙烯酸甲酯)∶n(丙烯酸)∶n(丙烯磺酸钠)=1.000∶0.100∶0.300∶0.200∶0.050,引发剂(NH4)2SO4为乙烯基单体质量的0.8%,反应温度为90℃,反应时间为2 h.应用结果表明:该减水剂减水率达32%,缓凝时间达5 h;掺该减水剂混凝土强度高、坍落度损失小、无泌浆离析现象.另外,用红外光谱(FTIR)和凝胶渗透色谱(GPC)对该减水剂分子结构进行了表征.
A new polycarboxylic acid type superplasticizer was synthesized by introducing citric acid to polycarboxylic acid molecule as branch in order to solve concrete＇s slump-loss, bleeding and segregation. The excellent superplasticizer was obtained when the molar ratio of polyethylene glycol acrylate （PEGAA）, polyethylene glycol citric acid maleate （PEGCM）, methyl acrylate （MA）, acrylic acid（AA） and sodium allylsulphonate（SAS） were 1. 000 ： 0. 100 ： 0. 300 ： 0. 200 ： 0. 050, the initiator was 0.8% （NH4）2SO4 by mass of vinyl monomers, the reaction temperature was 90℃ and the reaction time was 2 h. The application result shows that the superplasticizer＇s water-reducing ratio reaches 32%, retardation time extends 5 h, the concrete adding the superplasticizer have excellent slump retention, without segregations and with high compressive strength. The molecular structure was characterized by Fourier transform infrared spectroscopy （FTIR） and gel permeation chromatography（GPC）.
出处
《建筑材料学报》
EI
CAS
CSCD
2008年第5期515-521,共7页
Journal of Building Materials
基金
陕西省教育厅产业化项目(06JC21)
关键词
聚羧酸系
高效减水剂
混凝土
缓凝
polycarboxylic acid type
superplasticizer
concrete
retardation
