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以三聚氰胺(M)和甲醛(F)为原料、亚硫酸氢钠(SB)为磺化剂,采用四步法合成了三聚氰胺高效减水剂,并着重探讨了不同因素对该减水剂分散性能的影响。研究结果表明:采用单因素试验法优选出制备该减水剂的最佳工艺条件是n(M)∶n(F)∶n(SB)=1∶6∶1.3,羟甲基化阶段的温度、时间和pH分别为70℃、1.5 h和8.5,磺化阶段的温度、时间和pH分别为80℃、3.0 h和12,酸性缩聚阶段的温度、时间和pH分别为60℃、1 h和4,碱性重整阶段的温度、时间和pH分别为80℃、1 h和8.5;此时,该减水剂的分散性能相对最好,当w(减水剂)=1.0%(相对于水泥质量而言)时,水泥净浆的初始流动度(267 mm)相对最大。
Using melamine (M) and formaldehyde (F) as raw materials and sodium bisulfite (SB) as the sulfonating agent, a melamine superplasticizer was synthesized by a four-step method. The effects of different factors on the dispersant Impact. The results show that the optimal process conditions for preparing this water reducer are as follows: n (M): n (F): n (SB) = 1: 6:1.3, the temperature of the methylolation stage , The time and pH were 70 ℃, 1.5 h and 8.5 respectively. The temperature, time and pH of the sulfonation stage were 80 ℃, 3.0 h and 12, respectively. The temperature, time and pH of the acidic polycondensation stage were 60 ℃, 1 h and 4, the temperature, time and pH of the alkaline reforming stage were 80 ℃, 1 h and 8.5, respectively. At this time, the water-reducing agent had the best dispersing performance. When w (water reducer) = 1.0% Cement mass), the initial flow of cement paste (267 mm) is relatively greatest.