摘要
为揭示主链不同吸附基团对水泥吸附与分散和水泥浆体流变性能的影响,分别以单羧酸吸附基团的丙烯酸(AA)、双羧酸吸附基团的马来酸酐(MA)、磷酸吸附基团的异丙烯膦酸(IPPA)与异戊烯醇聚氧乙烯-聚氧丙烯醚(IPE12PP3G,Mw=762)进行自由基聚合反应制备了酸醚比、主链聚合度、侧链长度和侧链相同,但吸附基团不同的3种减水剂,并对其性能进行凝胶渗透色谱、红外光谱和核磁共振氢谱的分析获得了合成产物的相对分子质量及其分布等结构信息.同时测试了合成减水剂的络合能力、流体力学半径、水泥颗粒表面的吸附量、Zeta电位、吸附层厚度和水泥水化放热速率.结果显示,双羧酸吸附基团的马来酸酐合成的减水剂表现出更强的络合能力(Ca2p结合能与空白样发生化学位移分别为0.17 eV和0.07eV)、更小的流体力学半径(5.46 nm)、更大的吸附量(2.65 mN/m2)、Zeta电位(-26.507 mV)和吸附层厚度(1.16 nm),水泥水化放热速也相对最慢.
Abstract
In order to reveal the effects of different adsorption groups of the main chains on cement adsorption and dispersion and rheological properties of cement paste,polycarboxylate superplasticizer with different adsorption groups were prepared by radical polymerization of acrylic acid(AA)of monocarboxylic acid adsorption group,maleic anhydride(MA)of dicarboxylic acid adsorption group,isoacrylphosphonic acid(IPPA)of phosphoric acid adsorption group and isoprenyl alcohol polyoxyethylene-polyoxypropylene ether(IPE12PP3G,Mw=762).Three kinds of superplasticizer with the same acid-ether ratio,main chain polymerization degree,side chain length and side chain but different adsorption groups were prepared.The molecular weight,molecular distribution and structural information of the synthetic products were analyzed by gel permeation chromatography(GPC),infrared spectroscopy(FT-IR),and nuclear magnetic hydrogen spectroscopy(1H-NMR).And its complexing capacity,hydrodynamic radius,adsorption capacity,Zeta potential,adsorption layer thickness and hydration heat release rate were determined.The results show that the superplasticizer synthesized with maleic anhydride of dicarboxylic acid adsorption group shows stronger complexation ability(the chemical shift between Ca2p binding energy and blank sample is 0.17 eV and 0.07 eV,respectively),smaller hydrodynamic radius(5.46 nm),higher adsorption capacity(2.65 mN/m2),bigger Zeta potential(-26.507 mV)and thicker adsorption layer thickness(1.16 nm),and the hydration heat release rate of cement is still relatively slower than other two superplasticizers.
维普
万方数据