胶体粒子表面改性及其对水泥水化的影响

发布时间：2018-06-12 07:38

本文选题：聚合物乳液 + 表面电荷　；参考：《硅酸盐学报》2017年05期

【摘要】：通过乳液聚合制备了表面性质不同的两种阴离子乳液,即C4与CT乳液。C4乳液在制备过程中通过共聚甲基丙烯酸(MAA)使其中聚合物乳液粒子表面带负电荷,而CT乳液不仅共聚相同量的MAA单体,同时在合成中通过共聚异戊烯聚氧乙烯醚(TPEG),在乳液粒子表面引入非离子聚氧乙烯(PEO)毛梳层。通过水化热测试、颗粒表面电荷滴定、钙离子电极测试、等温吸附测试等实验探讨了两种乳液对水泥水化的影响及其内在机理。结果表明:与C4乳液相比,表面含非离子PEO毛梳层的CT乳液对水泥水化的抑制作用明显减弱;聚合物乳液粒子表面毛梳层不会降低羧基官能团对钙离子的络合能力;非离子PEO毛梳层的引入显著降低了聚合物乳液粒子在水泥颗粒表面的吸附量。两种乳液粒子在水泥颗粒表面吸附性能的差异是导致其对水泥水化不同影响的主要原因。
[Abstract]:Two kinds of anionic emulsions with different surface properties were prepared by emulsion polymerization, that is, C4 emulsion and CT emulsion .C4 emulsion were prepared by copolymerization of methacrylate (MAA), in which the surface of polymer emulsion particles was negatively charged. Ct emulsion not only copolymerized the same amount of MAA monomer, but also introduced Nonionic polyoxyethylene (PEO) comb layer on the surface of emulsion particles by copolymerization of isopentene polyoxyethylene ether (TPEG). The effects of two kinds of emulsions on cement hydration and their internal mechanism were investigated by means of hydration heat test, particle surface charge titration, calcium ion electrode test and isothermal adsorption test. The results show that compared with C4 emulsion, the inhibition of cement hydration by CT emulsion with non-ionic PEO comb layer on the surface is obviously weakened, and the complexation ability of carboxyl functional group to calcium ion is not decreased by the comb layer on the surface of polymer emulsion. The introduction of non-ionic PEO comb layer significantly reduced the adsorption capacity of polymer emulsion particles on the surface of cement particles. The difference of adsorption properties between the two kinds of emulsion particles on the surface of cement particles is the main reason leading to the different effects of the two kinds of emulsion particles on the hydration of cement.
【作者单位】：清华大学土木工程系建筑材料所;
【基金】：国家自然科学基金联合基金(U1301241)资助
【分类号】：O648.23;TQ172.1

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