| 摘要: |
| 通过水溶液自由基聚合法，利用丙烯酸羟乙酯、丙烯酰胺、2-丙烯酰胺-2-甲基丙磺酸和马来酸酐取代部分丙烯酸合成了含有不同官能团的聚羧酸系减水剂.通过测试水泥净浆流动度、减水剂在水泥净浆中的吸附量和水解行为，研究了官能团对减水剂缓释效应的影响机理.结果表明：含4种官能团的聚羧酸系减水剂对水泥净浆经时流动性均有不同程度的增强作用，含不同官能团的聚羧酸系减水剂在水泥净浆液相碱性环境下水解能力不同，从而影响减水剂在水泥颗粒表面的吸附量，最终导致缓释效应的差异，其中含酯基的聚羧酸系减水剂的缓释效应最为明显. |
| 关键词: 聚羧酸系减水剂 官能团 水解 缓释效应 |
| DOI：10.3969/j.issn.1007-9629.2022.03.007 |
| 分类号:TU528.042+.2 |
| 基金项目:国家自然科学基金资助项目（51678441）；上海市科委项目（19DZ1201404，19DZ1202702）；上海市建委项目（2021-001-002）；重庆市科技局专项项目（cstc2020kqjscx-phxm1594）；住建部项目（K20200988） |
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| Slow-Release Effect of Polycarboxylate Superplasticizers with Various Functional Groups |
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SUN Zhenping1,2,3, LI Zuyue1,2, PANG Min1,2, WU Lelin1,2, GE Haosheng1,2
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1.Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education , Tongji University , Shanghai 201804 , China;2.School of Materials Science and Engineering, Tongji University, Shanghai 201804 , China;3.Research Center of Intelligent Evaluation and Restoration Engineering Technology of Urban Pipe Network of Shanghai Water Bureau, Shanghai 201900, China
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| Abstract: |
| By replacing part of acrylic acid with hydroxyethyl acrylate（HEA）， acrylamide（AM）， 2-acrylamide-2-methylpropanesulfonic acid（AMPS） and maleic anhydride（MAH）， a series of polycarboxylate superplasticizers（PCE） with different functional groups were synthesized through free radical polymerization. By testing the fluidity of the cement paste， the adsorption capacity and hydrolysis behavior of the PCE in the cement paste， the mechanism of functional groups affecting the slow-release effect of the PCE was investigated. According to the results， the PCE containing these four functional groups enhances the fluidity retention of cement paste separately. The different hydrolysis ability of PCE in the pore solution can affect the adsorption amount of PCE on cement particles， and finally lead to the difference in slow-release effect. PCE with ester group shows the most obvious slow-release effect. |
| Key words: polycarboxylate superplasticizer functional groups hydrolysis slow release |
