磺化三聚氰胺-尿素-对氨基苯磺酸-甲醛树脂减水剂的合成

Synthesis of sulfonated melamine-urea-sulfanilic acid-formaldehyde resin superplasticizer

以三聚氰胺(M)、尿素(U)、对氨基苯磺酸(PAS)和甲醛(F)为主要原料,氨基磺酸(S)为磺化剂,采用四步法合成了SMUPASF(磺化三聚氰胺-尿素-对氨基苯磺酸-甲醛树脂)高效减水剂。系统探讨了合成工艺条件对SMUPASF分散性能的影响规律。研究结果表明:合成SMUPASF的最佳工艺条件是n(M)∶n(U)∶n(PAS)∶n(F)∶n(S)=1∶1∶1.0∶10∶1.2,羟甲基化阶段的反应温度为70℃、反应时间为1.5 h和p H=8.5,磺化阶段的反应温度为85℃、反应时间为2.5 h和p H=12.0,酸性缩聚阶段的反应温度为80℃、反应时间为1.5 h和p H=5.0,碱性重整阶段的反应温度为80℃、反应时间为1.0 h和p H=8.5;此时,SMUPASF的综合性能良好,当w(SMUPASF)=1.0%(相对于水泥质量而言)时,其分散性能较好,水泥净浆初始流动度(达235 mm)相对最大。

With melamine （ M）, urea （U）, sulfanilic acid （PAS） and formaldehyde （F） as main raw materials, sulfamic acid （S） as sulfonating agent, a SMUPASF （sulfonated melamine- urea- sulfanilic acid- formaldehyde resin） superplasticizer was synthesized by four steps method. The influence rule of the synthesizing process conditions on the dispersibility of SMUPASF was systematically discussed. The research results showed that the optimal process conditions of synthesizing SMUPASF were obtained when molar ratio of n （M） ： n （U） ：n （PAS） ： n（F） ： n（S） was 1： 1： 1.0： 10： 1.2, reaction temperature, reaction time and pH were 70 ℃, 1.5 h and 8.5 at hydroxymethylation stage, 85 ℃, 2.5 h and 12.0 at sulfonate stage, 80 ℃, 1.5 h and 5.0 at acidic polycondensation stage, 80 ℃, 1.0 h and 8.5 at alkaline reforming stage, respectively. Here, the SMUPASF had the good combination property, and its dispersibility was better because the initial cement paste fluidity （235 mm） was relatively maximal when mass fraction of SMUPASF was 1.0% in cement.