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以三聚氰胺(M)、对羟基苯甲酸(PHA)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SMPHAF(磺化三聚氰胺-对羟基苯甲酸-甲醛树脂)高效减水剂。研究结果表明:当n(M)∶n(PHA)∶n(F)∶n(SB)=1∶0.10∶5.6∶1.5、羟甲基化阶段的反应温度为60℃、反应时间为1.5 h和p H为8.5,磺化阶段的反应温度为80℃、反应时间为3.0 h和p H为12.0,酸性缩聚阶段的反应温度为60℃、反应时间为1.0 h和p H为3.5,碱性重整阶段的反应温度为80℃、反应时间为1.0 h和p H为8.5时,合成的SMPHAF具有良好的综合性能;当w(SMPHAF)=1.0%(相对于水泥质量而言)时,混凝土体系具有较好的分散性,水泥净浆的初始流动度(245 mm)相对最大。
In this paper, SMPHAF (sulfonated melamine-p-hydroxybenzoic acid-p-hydroxybenzoic acid) was synthesized by four steps using melamine (M), p-hydroxybenzoic acid (PHA) and formaldehyde (F) as raw materials and sodium bisulfite (SB) as sulfonating agent. Formaldehyde resin) superplasticizer. The results show that when the reaction temperature is 60 ℃ and the reaction time is 1.5 h at n (M): n (PHA): n (F): n (SB) = 1: 0.10: 5.6: And p H is 8.5, the reaction temperature in the sulfonation stage is 80 ° C, the reaction time is 3.0 h and the p H is 12.0, the reaction temperature in the acidic polycondensation stage is 60 ° C, the reaction time is 1.0 h and the p H is 3.5, the basicity The reaction temperature of the reforming stage was 80 ℃, the reaction time was 1.0 h and p H was 8.5, the synthetic SMPHAF had good comprehensive performance. When w (SMPHAF) = 1.0% (relative to the mass of cement) The system has better dispersion, the initial flow of cement paste (245 mm) is relatively largest.