《萘系高效减水剂的合成及性能研究》-毕业论文.doc

PAGE 萘系高效减水剂的合成及性能研究 摘 要 本文采用工业萘、硫酸、甲醛、液碱为原料，经磺化、水解、缩合、中和等步骤生产混凝土高效减水剂β—萘磺酸甲醛缩合物钠盐(FDN)，以净浆流动度及坍落度为指标对工艺指标、控制方法，工业生产设备进行了选择及优化。 本文研究了工业萘和硫酸的不同比例、反应温度，水解温度及加水量、缩合条件对所得产物减水性能及保坍性能的影响。通过分析比较确定了工业上合成β—萘磺酸甲醛缩合物钠盐(FDN)的较好工艺为: n( 甲基萘) ：n( 浓硫酸) ：n( 水解加水量) ：n( 甲醛) ：n( 缩合加水量)=1：1.4：2.2：0.90：4.6；磺化反应温度为160~165℃，反应时间为2.5~3小时；水解反应温度为120℃；缩合时控制酸度在28%左右，缩合温度为110℃，缩合时间为4小时；缩合完毕后用30%的液碱中和至pH为7~9。产品在国标掺量下水泥净浆流动度可达到240mm，同时在坍落度经时损失、混凝土抗压强度、泌水率等方面均取得较好的效果，生产工艺可以在工业生产上应用。 关键词：萘系高效减水剂；混凝土；工业萘；硫酸；甲醛 Research on the synthesis and performance of naphthalene superplasticizer Abstract By using of industrial naphthalene, sulfuric acid, formaldehyde, NaOH as raw material, β—naphthalene sulfonic acid formaldehyde condensate sodium salt (FDN)，which is concrete superplasticizer，was synthesized after sulfonation, hydrolysis, condensation and neutralization reaction process. Effect of technology and control methods on paste fluidity and slump degree have been investigated, and technology factors, control methods and production equipment have been selected and optimizated. In this paper, the influence of industrial naphthalene and sulfuric acid ratio, reaction temperature, hydrolysis temperatures, the addition conent of water, and condensation condition on plastic and slump performance were studied. By analysis and comparison of technology factors, the industrial synthesis of β-naphthalene sulfonic acid formaldehyde condensate sodium salt (FDN) was determined as follows: n (DMN): n (sulfuric acid): n (hydrolysis plus water): n (formaldehyde) : n (condensation adding water) = 1:1.4:2.2:0.90:4.6; sulfonation reaction temperature was 160~165 ℃, reaction time was 2.5~3 hours; hydrolysis reaction temperature was 120℃; control acidity was 28% during condensation process , condensation temperature was 110℃, the condensation time was 4 hours; after condensation process, the pH of production was adjusted to 7~9 by NaOH sloution. the paste fluidity was 240mm under the addition conent of FDN at the GB