| 摘要: |
| 采用水溶液自由基共聚法，将乙二醇单乙烯基聚乙二醇醚与丙烯酸共聚合成了聚羧酸系减水剂（PCEs），深入研究了反应温度、滴加时间和链转移剂用量3个主要因素对PCEs分子结构和分散性的影响及机理.结果表明，反应温度和链转移剂用量对乙二醇单乙烯基聚乙二醇醚的转化率、PCEs的相对分子质量及其分布影响较大，导致PCEs在水泥净浆中的分散性和分散保持性有明显的区别，而滴加时间的影响相对较小. |
| 关键词: 聚羧酸系减水剂 乙烯醚类大单体 反应条件 分子结构 分散性 |
| DOI：10.3969/j.issn.1007-9629.2024.02.005 |
| 分类号:TU528.042.2 |
| 基金项目:国家自然科学基金资助项目（52278272）；上海市科委项目（19DZ1202702，19DZ1201404）；上海市建委专项课题（住建管2021-001-002）；重庆市科技局专项项目（cstc2020kqjscx-phxm1594）；内蒙古自治区科技计划项目（2022YFDZ0063）；上海市科委外国专家项目（22WZ2502400）；云南省科技厅专家工作站项目（202105AF150243）；中铁上海工程局课题（SH-2020-重点-19） |
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| Effect and Mechanism of Reaction Conditions on Molecular Structure and Dispersion of PCEs |
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ZHAO Xuesong1,2, SUN Zhenping1,2,3, YANG Haijing1,2, LUO Qiong4, MA Yuefei5
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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;4.Satellite Chemical Co.， Ltd.， Jiaxing 314004， China;5.Ulanhot Shengyi Commercial Concrete Co.， Ltd.， Ulanhot 137499， China
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| Abstract: |
| Polycarboxylate superplasticizers（PCEs） were synthesized by free radical copolymerization of vinyl ethylene glycol monovinyl polyethylene glycol ether and acrylic acid in aqueous solution. The effects of reaction temperature， dropping time and chain transfer agent dosage on the molecular structure and dispersion of PCEs were investigated. The results show that the reaction temperature and chain transfer agent dosage have a great influence on the conversion rate of ethylene glycol monovinyl polyethylene glycol ether， the molecular weight and its distribution of PCEs， resulting in the significant differences in the dispersibility and retention of PCEs in cement paste，while the effect of dropping time is relatively small. |
| Key words: polycarboxylate superplasticizer ethylene ether macromonomer reaction condition molecular structure dispersion |
