文献类型：期刊文献

英文题名：Study on the Impact of Na/Ca Bentonites on the Dispersion Performance of Conventional and Modified Phosphate Polycarboxylate Superplasticizers in Cement Mortar

作者：Feng, Hui[1];Mao, Yucheng[2,3];Feng, Zhongjun[2,3];Deng, Zuiliang[2,3];Zheng, Baicun[1]

机构：[1]East China Univ Sci & Technol, Res & Dev Ctr Sports Mat, Shanghai 200237, Peoples R China;[2]Shanghai Sunrise Polymer Mat Co Ltd, Shanghai 200231, Peoples R China;[3]Shanghai Engn Res Ctr Construct Admixture, Shanghai 200231, Peoples R China

年份：2022

卷号：38

期号：18

起止页码：5803

外文期刊名：LANGMUIR

收录：;EI(收录号：20222012119371);WOS:【SCI-EXPANDED(收录号:WOS:000813315900001)】；

基金：This work was supported by the Science and Technology Commission of Shanghai Municipality (grants nos. 18QB1403200, 17520730200, and 15DZ2282500).

语种：英文

外文关键词：Bentonite - Cements - Dispersions - Ethers - Ethylene - Ethylene glycol - Fluidity - Monomers - Mortar - Polyols

摘要：Through molecular structure design, modified polycarboxylate superplasticizers (PCEs) were synthesized via copolymerization using isoprenyl oxy polyethylene glycol) ether (TPEG), acrylic acid, and hydroxyethyl methacrylate phosphate. TPEG-PCEs were selected as potential dispersants for Na/Ca-bentonite containing cement mortar. Other two kinds of commercial PCE that were obtained based on methallyl ether (HPEG) and ethylene-glycol monovinyl polyethylene glycol (EPEG) as macromonomers were also applied in the mortar. The effects of the type of bentonite and its dosage, as well as the monomer structure of PCEs and the type of cement, on the dispersion properties of the bentonite-containing mortar were studied. According to the findings, the initial fluidity of the mortar was reduced by about 20 mm when two kinds of bentonite were used. Applying 3% Ca-bentonite resulted in 40% flow loss in the mortar after 1 h. The fluidity of the mortar with Na-bentonite exhibited lower dispersion ability than that with Ca-bentonite when HPEG-PCE and EPEG-PCE were chosen as dispersants. The TPEG-PCE exhibited superior dispersing performance over HPEG-PCE and EPEG-PCE and exerted a retarding effect on cement, being also weakly sensitive to clay content. Thus, TPEG-PCEs with phosphate groups present a viable alternative to conventional PCEs.