摘要
为高效制备高性能增强型聚羧酸减水剂,以丙烯酸、甲基丙烯酰氧乙基三甲基氯化铵、聚醚为原料,通过水溶液自由基聚合法常温合成了两性聚羧酸减水剂。最佳合成工艺为:聚合温度25℃,反应40 min保温1 h,酸醚比4.0∶1,TGA、H_(2)O_(2)、VC用量分别为EPEG质量的0.30%、0.90%、0.15%,合成的减水剂分散性能能好,增强效果显著。XRD与SEM等分析表明,减水剂折固掺量低于0.2%时,早期均表现对水化微弱的抑制作用,主要影响1 d内氢氧化钙与3 d内钙矾石的生成,掺量越高抑制作用越大;减水剂掺量为0.2%时,3 d内钙矾石的生成减少,但氢氧化钙的分散性能和结晶度提高,7 d龄期时促进生成更多的硅酸盐凝胶,整体密实度高。
In order to prepare high performance enhanced polycarboxylic acid water reducing agent,amphoteric polycarboxylic acid water reducing agent was synthesized by aqueous free radical polymerization method at room temperature with acrylic acid,methacryloyloxyethyl trimethyl ammonium chloride and polyether as raw materials,the polymerization temperature was 25℃,the reaction was 40 min and holding time was 1 h,the acid to ether ratio was 4.0∶1,TGA、H_(2)O_(2) and VC accounted for 0.30%、0.90%and 0.15%of the mass of polyether monomer respectively,the dispersion performance of the water reducing agent is good and the enhancement effect is significant.XRD and SEM analysis showed that when the volume of water reducer was less than 0.2%,it had a weak inhibitory effect on hydration at early stage,mainly affecting the formation of calcium hydroxide in 1 d and calcium alumina in 3 days,and the higher the dosing,the greater the inhibitory effect.When the content of water reducer is 0.2%,the formation of ettringite is reduced within 3 days,but the dispersion and crystallinity of calcium hydroxide are improved.At the age of 7 days,more silicate gel is generated,and the overall compactness is high.
作者
刘衍东
柯凯
吕阳
LIU Yandong;KE Kai;LYU Yang(School of Materials and Chemical Engineering,Hubei University of Technology,Wuhan 430068,China;State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China)
出处
《新型建筑材料》
2023年第3期112-117,共6页
New Building Materials
基金
国家自然科学基金面上项目(51872215)
国家自然科学基金青年科学基金项目(51808420)。
关键词
常温合成
两性聚羧酸减水剂
氢氧化钙
钙矾石
水化硅酸钙
synthesis at room temperature
amphoteric polycarboxylic acid water reducer
calcium hydroxide
ettringite
hydrated calcium silicate
