摘要 聚羧酸系减水剂是国内外公认的新型、绿色环保减水剂，具有掺量低、保塑性强、坍落度损失低、水泥适应性广等优点，研究开发该类减水剂具有良好的研究与应用前景，并且目前在我国的研究尚处于起步阶段。本文主要以水解聚马来酸酐（PMA）为主链，以聚乙二醇单甲醚(MPEG)为长支链，在催化剂的作用下，并加入一定量的溶剂 N-N-二甲基甲酰胺，通过酯化反应合成出具有具有梳形结构的高性能减水剂，并对其性能进行了评价。本文采用正交设计试验法，考察了酯化反应的酸醇摩尔比、反应温度、催化剂掺量、溶剂掺入量等对聚羧酸系高效减水剂性能的影响。最终确定理想的反应条件是：酸醇官能团摩尔比比为 15：1，酯化温度为 85，催化剂掺入量为4，溶剂掺入量为 30。同时采用单因素条件试验法，确定了三乙胺作为催化剂的效果明显优于用 NaOH 做催化剂的。本文还设计一套完整有效的聚羧酸减水剂的提纯方法：逐步降温沉降法和萃取工艺，使减水剂的综合性能大幅度提高，进一步完善和提高了 PMA- MPEG 型聚羧酸系高效减水剂的制备工艺。性能测试结果表明，聚羧酸系高效减水剂减水率可达30，掺入量为03时，水泥净浆流动度达到235 mm，通过提纯后可达285mm；掺入该高效减水剂0.3%的混凝土，120min坍落度经时损失仅为1.5cm；掺入该高效减水剂0.43%的混凝土，28天混凝土抗压强度比空白实试验高近20Mpa。此外，该高效减水剂与水泥有良好的相容性。因此，通过优化合成工艺，制得的新型聚羧酸系高效减水剂是性能优越的高效减水剂。关键词：聚羧酸；高效减水剂；酯化；步降温沉降法；萃取；净浆流动度；塌落度；强度ABSTRACTPolycarboxylate-type water-reducing agents are reconized both home and abroad as the new and environment-friendly water reducers with a lot of characteristics such as low dosage,strong maintaining plastic,low slump loss and wide adaptability to cement. Researching and developing such water-reducing agent have good prospects for research and application, and current research in our country is still in its infancy.In this paper, together with the hydrolysis of maleic anhydride (PMA)- backbone, with polyethylene glycol monomethyl ether (MPEG) for the long branched-chain, in the role of catalyst and solvent by adding a certain amount of NN-dimethyl-carbamoyl amines, were synthesized through esterification with comb-shaped structure with a high-performance water-reducing agent, and its performance was evaluated. In this paper, orthogonal design test method was used to study the esterification of molar ratio of acid to alcohol, reaction temperature, catalyst content, the volume of solvent and so on ,affecting polycarboxylate superplasticizer performance. Ultimately determined the ideal reaction conditions were: acid alcohol functional group molar ratio of 15:1 , esterification temperature of 85 , catalyst incorporation of 4%, mixed solvent of 30%. At the same time, the conditions of single-factor test to determine the triethylamine as a catalyst was better than the use of NaOH as catalyst. This article also designed a set of complete and effective purification methods of polycarboxylate superplasticizer: Settlement gradually cooling and crafts of extraction process, so that superplasticizers overall performance increased Significantly ,further improved and enhanced the PMA-MPEG-type polycarboxylate superplasticizer Preparation.Test results show that the water reducing rate of polycarboxylate-type superplasticizer can be as high as 30The fluditity of cement can be as high as 235mm,but can be as high as 285mm after purification ,when the dosage of polycarboxylate-type superplasticizer is 0.3. The concrete with 0.3% superplasticizer, slump loss was only 1.5cm after 120min; the concrete with 0.4% superplasticizer, the 28-day compressive strength of concrete was more nearly 20Mpa than the blank test.Furthermore,the com -patibility of polycarboxylate-type superplasticizer and different cements is very goodSo throhgh optimizing the synthesis process ,the Obtained novel polycarboxylate-type high range water reducer is a sort of waterreducing admixture which has great propertiesKeywords: polycarboxylate；superplasticizer；esterification； Sedimentation step cooling； extraction；Paste fluidity； Slump； intensity目 录摘要绪论Abstract 第 1 章 绪论 11.1 聚羧酸系高效减水剂概述 11.1.1 聚羧酸系高效减水剂的定义 11.1.2 聚羧酸系高效减水剂的分类 11.1.3 聚羧酸系减水剂的性能特点 21.1.4 聚羧酸系高效减水剂在工程中的应用 31.2 聚羧酸系高效减水剂的研究现状 71.2.1 研究背景71.2.2 国外聚羧酸系高效减水剂的研究及应用现状71.2.3 国内聚羧酸系高效减水剂的研究及应用现状91.2.4 聚羧酸系高效减水剂的发展方向 101.3 本课题的提出及研究方案111.3.1 本课题的提出 111.3.2 本课题的研究方案12第 2 章 聚羧酸系高效减水剂的分子设计131.1 聚羧酸系高效减水剂作用机理132.1.1 分散作用机理132.1.2 抑制坍落度损失机理172.2 聚羧酸系高效减水剂结构与性能的关系192.3 聚羧酸系高效减水剂分子结构21第 3 章 原材料与实验方法253.1 实验原料253.1.1 制备减水剂原料的选择253.1.2 合成用助剂263.2 仪器设备263.3 聚羧酸系高效减水剂性能测试方法273.3.1 净浆流动度的测试方法273.3.2 混凝土塌落度的测试方法283.3.3 混凝土抗压强度测试方法283.4 合成方法的选择293.4.1 聚羧酸减水剂的合成方法293.4.2 本实验采用合成方法303.4.3 合成工艺流程313.5 实验设计323.5.1 聚羧酸系高效减水剂的合成条件选择323.5.2 采用正交实验酯化实验设计333.5.3 采用单因素酯化实验设计333.6 聚羧酸系高效减水剂复合提纯343.6.1 采用逐步降温沉降法初步提纯353.6.2 采用萃取法精细提纯35第 4 章 聚酸酸系高效减水剂的实验结果及分析374.1 采用正交试验结果分析374.2 不同催化剂对实验结果的影响404.3 采用逐步降温沉降法初步