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机构地区:[1]华南理工大学化工与能源学院,广东广州510640
出 处:《现代化工》2004年第9期40-43,共4页Modern Chemical Industry
基 金:广东省科技攻关项目资助课题(2002C1030305)
摘 要:采用三步法代替以往的四步法并以廉价的尿素代替部分价格昂贵的三聚氰胺,合成了具有高减水分散性能的磺化三聚氰胺脲醛树脂(SMUF),简化反应工艺,使羟甲基化和磺化同时进行。研究了磺甲基化反应、缩聚反应和重整反应工艺参数对SMUF分散性能的影响,适宜的反应条件为:原料比n(甲醛):n(三聚氰胺):n(尿素):n(磺化剂)=6:1:1:2时,磺甲基化反应(pH值11.0-11.5,60 min)、酸性缩聚反应(pH值4.5,60-75 min)及碱性重整反应(pH值7-8)温度均在80℃下进行。初步探索了三步法中磺甲基化反应机理。A new three-step synthetic route, including sulfomethylation, low pH condensation and high pH rearrangement, for synthesizing sulfonated melamine urea-formaldehyde resins (SMUF) was proposed. The factors affecting the properties of SMUF as superplasticizer in cement were studied. The optimal conditions for preparation are as follows: 6:1:1:2 of sulphite/melamine/urea/sulfonating reagent molar ratio, and the temperature of all three steps is 80°C; the sulfomethylation stage taking place under 11.0-11.5 of pH value for 60 min, the low-pH condensation stage under 4.5 of pH value for longer than 60 min, and the high-pH rearrangement stage under 7-8 of pH value. The mechanism of the reaction of SMUF was elementally studied.
关 键 词:磺化三聚氰胺脲醛树脂 超塑化剂 三步法合成路线
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