具有缓释作用的聚羧酸分散剂的制备及机理研究

Preparation and mechanism research of polycarboxylate dispersant with slow-release effect

选用聚醚和羟基酯通过自由基聚合成了缓释型聚羧酸分散剂,通过核磁共振氢谱对结构进行了表征,并运用zeta电位和吸附动力学对其作用机理进行了探索,研究表明,羟基酯在水泥的碱性环境下能够释放出吸附基团,进而补充被水化产物覆盖的分散剂发挥分散作用,且随着时间的延长,可吸附的分散剂持续增加,使其对水泥颗粒的分散性在一定时间范围内逐渐增强。另外,随着羟基酯比例的增加,释放的吸附基团增加,分散作用增加。

Slow-released polycarboxylate dispersants were synthesized with polyether and hyciroxy esters by tree radical polymerization. The structure of products were identified by 1H NMR spectra, and the mechanism of dispersion was explored by zeta potential and adsorption kinetics. The results showed that hydroxyl esters could release adsorptive group in alkaline environment of cement, to play a role of dispersion as supplementary disper- sant covered by hydration products. The adsorption of dispersants continued to increase with the time, the dis- persion of cement particles in a certain time gradually enhanced. In addition, with the increase of hydroxy esters ratio, the release of adsorptive groups increased, the dispersion effect increased.