Synthesis of phosphonated comb-like copolymers and evaluation of their dispersion efficiency on CaCO3 suspensions. Part I: Effect of an increasing phosphonic acid content

• Published in: Powder technology 2018-06, Vol.333, p.19-29
• Main Authors: Tramaux, A., Azéma, N., David, G., Negrell, C., Poulesquen, A., Haas, J., Remond, S.
• Format: Article
• Language: English
• Subjects: Adsorption; Calcite; Chemical Sciences; Dispersion; Macromolecular structures; Organic chemistry; Superplasticizers; Suspensions
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2018.03.069

Superplasticizers are admixtures widely used in the building industry for reducing the water content of concrete with a high fluidity and workability at short term, and for increasing concrete mechanical properties at long term. Polycarboxylates, which are synthetic comb-like copolymers, are the most used superplasticizer admixtures. In order to improve polycarboxylate efficiency and compatibility with use of mineral additives, high-sulfate concretes etc., various authors tried to change macromolecular architectures, including nature of anionic function. This paper is the first part of a study which presents synthesis of several macromolecular architectures of comb-like copolymers with phosphonic acid functions instead of classical carboxylic acid. Adsorption, dispersion and fluidification efficiency of these admixtures are evaluated on calcite suspensions in order to simulate early-age cement behavior. Moreover, settling behaviors are studied in order to characterize dispersion ability of synthetized polymers. [Display omitted] •Synthesis of three macromolecules with various ratios of phosphonic acid functions•Synthesis of a block comb-like copolymer with phosphonic acid moieties•Relationship between phosphonic acid content and macromolecular structure•Evaluation of adsorption and dispersion efficiency•Proposition of a stability index to classify polymer dispersion ability