中文摘要：

由于保护环境的原因，以天然高分子为原料来合成高效减水剂已经成为混凝土外加剂研究领域的新热点．本文研究了采用磺化糊精取代部分功能大单体来合成复合聚羧酸减水剂的方法．结果显示：当磺化糊精取代功能单体40％、复合聚羧酸减水剂掺量为0．5％时，水泥净浆的初始流动度达255mm，1h后其流动度仍为250mm．淀粉酸解后，增加亲水的羟基基团导致初期水化缓慢，而增加Zeta电位使水泥颗粒更易于分散．在复合减水剂中，长链Starch与短链的聚羧酸减水剂主链将被吸附于水泥颗粒表面上，交替发生静电与空间位阻作用，起到了增加减水率和降低缓凝的效果．

英文摘要：

Nowadays, for environmental protection, the synthesis of superplasticizer with natural polymers has become a new hot spot in the research field of concrete admixture. In this paper, a research has been done on the method of synthesizing the compotmd polycarboxylate superplasticizer with the partial substitution of sulfonation dextrin for big fimctional monomer. The results showed that the initial fluidity of cement paste reaches 255 mm with 40% substitution amount of sulfonated dextrin for functional monomer and 0.5% compound polycarboxylate superplasticizer, and 1 hour＇s later its fluidity reaches 250 mm. After the acid-hydrolysis of the starch, the increase of hydrophilic group results in slower initial hydration reaction of cement, and the increases of the Zeta potential make it easier to disperse cement particles. In the compound superplasticizer, the long-chain starch and the short-chain polycarboxylate superplasticizer main chain are adsorbed on the surfaces of cement particles, which have water-reducing and set retarding effects due to the alternating effects of electrostatic interaction and steric hindrance.