以氨基磺酸为磺化剂合成三聚氰胺系高效减水剂

Synthesis of melamine-superplasticizer with aminosulfonic acid as sulphonating agent

以三聚氰胺(M)和甲醛(F)为原料,氨基磺酸(A)为磺化剂,合成了M系高效减水剂。探讨了反应物配比、反应温度、反应时间和体系pH等对M系高效减水剂分散性能的影响。研究结果表明:当n(M)∶n(F)∶n(A)=1∶5∶1.7,羟甲基化阶段的反应温度为70℃、反应时间为1.5 h和pH为8.5,磺化阶段的反应温度为90℃、反应时间为3 h和pH为12,酸性缩聚阶段的pH为6、反应温度为90℃和反应时间为1 h,碱性重整阶段的反应温度为60℃、反应时间为1 h和pH为8.5时,合成的减水剂具有良好的综合性能;当w(减水剂)=0.5%(相对于水泥质量而言)时,减水剂的分散性能良好,水泥净浆初始流动度达245 mm;当w(减水剂)=0.6%时,混凝土的减水率达到13.8%且具有较高的坍落度保持率。

With melamine（M）and formaldehyde（F）as raw materials,aminosulfonic acid（A）as sulphonating agent,a melamine（M）-superplasticizer was synthesized. The influences of some factors such as molar ratio of reactant,reaction temperature,reaction time and pH of system on dispersibility of M- superplasticizer were discussed. The research results showed that the made superplasticizer had the good combination property when molar ratio of n（M）∶n（F）∶n（A）was 1∶5∶1.7,reaction temperature,reaction time and pH were 70 ℃,1.5 h and 8.5 respectively in hydroxymethylation stage,90 ℃,3 h and 12 respectively in sulfonate stage,90 ℃,1 h and 6 respectively in acid polycondensation stage,60 ℃,1 h and 8.5 respectively in alkaline rearrangement stage. The superplasticizer had the good dispersibility because the initial fluidity of cement paste was 245 mm when mass fraction of superplasticizer was 0.5% in cement. The concrete,which water-reducing rate was 13.8%,had the higher retention rate of slump when mass fraction of superplasticizer was 0.6%.