聚醚大单体溶液pH对减水剂性能的影响  

Effect of pH of Polyether Macromolecule Solution on Properties of Water Reducer

作　　者：张国宏 李晓利 张瑞琳 魏晓波[1] 李虹阳 ZHANG Guo-hong;LI Xiao-li;ZHANG Rui-lin;WEI Xiao-bo;LI Hong-yang(School of Chemical Equipment,Shenyang University of Technology,Liaoyang 111003,Liaoning,China)

机构地区：[1]沈阳工业大学化工装备学院

出　　处：《精细化工》2019年第11期2297-2301,2308,共6页Fine Chemicals

摘　　要：以甲基烯丙醇聚氧乙烯醚和丙烯酸为主要原料,对聚醚单体溶液(底料)pH进行调控合成聚羧酸减水剂。通过测定聚醚转化率及减水剂相对分子质量及其分布以及评价减水剂的应用性能,确定了聚醚大单体溶液pH变化范围以及不同酸种类对减水剂性能的影响。结果显示,通过控制底料pH提高了聚醚大单体转化率,并且当底料pH控制为3时其转化率最高,由未调控pH的87.41%提升至pH为3时的95.43%,此时合成减水剂的分子量分布指数较小,由未调控pH时的3.183降至2.884;采用硫酸控制底料pH时,溶液中存在的硫酸盐为硫酸钠,其快速溶解减少了聚羧酸减水剂被水泥水化产物的包裹和消耗,更有利于提高聚羧酸减水剂分散性能。结果表明,通过控制聚醚大单体溶液pH的方式,在不改变减水剂合成工艺操作的前提下也可提升聚羧酸系减水剂的整体性能。A polycarboxylate-based water reducer was synthesized with methyl allyl alcohol polyoxyethylene ether and acrylic acid as main raw materials by controlling p H of polyether monomer solution(base material). The pH range of polyether macromonomer solution and the effect of different acid types on the performances of water reducer were determined by measuring the conversion of polyether, the water reducer’s relative molecular weight and molecular weight distribution index, and evaluating the application performances of water reducer. The results showed that the conversion rate of polyether monomer was increased by controlling the pH of the base material. When the pH was controlled at 3, the conversion rate of polyether was the highest, which increased from 87.41% of the blank to 95.43%. Moreover, the molecular weight distribution index of synthetic water reducer was the lowest, decreasing from 3.183 to 2.884. When sulfuric acid was used to control the pH of the base material, sodium sulfate was present in the solution, its rapid dissolution reduced the encapsulation and consumption of polycarboxylate superplasticizer by cement hydration products, which was more conducive to improving the dispersibility of polycarboxylate superplasticizer. The results revealed that the overall performance of polycarboxylate superplasticizer can be improved by controlling the pH of polyether macromonomer solution without changing the synthetic process of water reducer.

关 键 词：聚羧酸系减水剂 聚醚转化率 分子量分布指数 底料pH调控 建筑用化学品 

分 类 号：TU528.042.2[建筑科学—建筑技术科学]