Dispersing Agents For Cement Based On Modified Polysaccharides
Dispersing Agents For Cement Based On Modified Polysaccharides
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DOI：
10.1016/j.cemconres.2004.09.022
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发表时间：
2005-05
影响因子：
11.4
通讯作者：
M. C. Vieira;D. Klemm;L. Einfeldt-;G. Albrecht
中科院分区：
文献类型：
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作者：
M. C. Vieira;D. Klemm;L. Einfeldt-;G. Albrecht
本文对淀粉和纤维素阴离子衍生物进行了研究，目的是获得用于砂浆和混凝土混合物的新型可生物降解分散剂。为此，对不同的淀粉和纤维素材料进行部分解聚，得到 DPw50–300 的极限糊精和 DPw30–150 的平衡 DP (LODP) 纤维素。这些部分水解的多糖随后的羟乙基化、羧甲基化或磺乙基化在2-丙醇中发生，而硫酸化在二甲亚砜中进行。通过 GPC 表征样品的分子量，通过 NMR 光谱表征化学结构和官能化模式，并测定样品溶液的流变行为。分散剂产品作为砂浆和混凝土外加剂进行了测试。结果表明，部分水解和磺乙基化的直链淀粉（70% 直链淀粉）提供了最有效的分散剂。结果与超增塑剂（即聚羧酸酯醚）的结果相当。
In this paper, starch and cellulose anionic derivatives are investigated with the objective to obtain new biodegradable dispersing agents for mortar and concrete mixtures. For that purpose, different starch and cellulose materials were partially depolymerized, giving limit-dextrins with DPw50–300 and level-off-DP (LODP) celluloses with DPw30–150. The subsequent hydroxyethylation, carboxymethylation, or sulfoethylation of these partially hydrolyzed polysaccharides occurred in 2-propanol, whereas the sulfation was carried out in dimethyl sulfoxide. The molecular weights of the samples were characterized by means of GPC, the chemical structure and functionalization pattern by means of NMR spectroscopy, and the rheological behavior of the sample solution was also determined. The dispersant products were tested as mortar and concrete admixtures. As a result, it could be shown that partially hydrolyzed and sulfoethylated amylomaize starch (70% amylose) provides the most efficient dispersing agent. The results were comparable to those of superplasticizers (i.e., polycarboxylate ethers).