淀粉基减水剂的合成与性能研究

Synthesis and performance of starch-based water-reducing agent

根据淀粉的化学性质及高效减水剂的作用机理,以玉米淀粉为原料,采用硫酸酯化的方法合成出一种以脱氧葡萄糖长链为憎水基,羟基和磺酸基为亲水基的缓凝型减水剂(ST)。试验结果表明,ST的最佳合成参数为:m(淀粉∶)m(N,N-二甲基甲酰胺用量)∶m(硫酸酯化试剂)=1∶2∶0.5,反应温度90℃,反应时间3 h。红外光谱分析结果表明,ST分子结构上成功引入了磺酸基团。ST对水泥的分散性能和砂浆减水率都明显优于萘系高效减水剂FDN,且对混凝土28 d强度有明显的增强作用。

According to the chemical property of start：h and effective mechanism of high-efficiency water-re＇ducing agent,a new-type water-reducing retarder（ST）contained hydrophobie groups of deoxyglucose chain and hydrophilic groups of hydroxy groups and sulphonic groups was prepared by sulfated corustarch. The test results show that the optimum synthesize parameters of ST were that the mass ratio of partially hydrnlyzed starch, N,N-dimethylformarnide and sulfated agent was 1：2：0.5,the reaction temperature was 90 ℃,and the reaction time was 3 h.The 1R spectrum analysis result showed that sulphonie groups were introduced into molecular structure,and the dispersing of ST and water reducing ratio of cement mortar were superior to Naphthalene Superplasticizer（FDN） ,and 28 d strength of concrete was increased obviously.