Organic-inorganic composites based on magnesium phosphate cement and acrylic latexes: Role of functional groups

0561894 - ÚTAM 2023 RIV GB eng J - Journal Article
Zárybnická, Lucie - Machotová, J. - Mácová, Petra - Viani, Alberto
Organic-inorganic composites based on magnesium phosphate cement and acrylic latexes: Role of functional groups.
Ceramics International. Roč. 49, č. 3 (2023), s. 4523-4530. ISSN 0272-8842. E-ISSN 1873-3956
R&D Projects: GA ČR(CZ) GA20-01280S
Institutional support: RVO:68378297
Keywords : magnesium phosphate cement * acrylic latex * carboxyl groups * emulsion polymerization
OECD category: Materials engineering
Impact factor: 5.2, year: 2022
Method of publishing: Limited access
https://doi.org/10.1016/j.ceramint.2022.09.338

The role of carboxyl functional groups in acrylic latex employed to fabricate an organic-inorganic composite material based on magnesium phosphate cement has been investigated. The acidic nature of the latex aqueous medium enhanced the dissolution of the magnesium oxide in the first stages of the cement reaction. The following increase in pH promoted the deprotonation of the carboxyl groups, which became involved in surface adsorption effects. Adsorption processes were found to control the nucleation and growth of the reaction products. The resulting overall hindering effect slowed down the reaction rates and delayed the precipitation of the solid phosphates with beneficial consequences, namely, the retardation of setting time and the modulation of the heat released. Modification in the morphology of the formed crystals, with the prevalence of platelet-like over prismatic habit, along with a decrease in their average size, was obtained. The crystals formed in higher amounts with respect to the neat cement because the reaction proceeds closer to equilibrium. The obtained microstructure is strengthened because of a more effective intermingling between crystals and the amorphous phase. Furthermore, the synergistic combination of polymer and phosphate cement improved the elastic properties, and
reduced the water absorption, impacting positively on the durability of the composite.
Permanent Link: https://hdl.handle.net/11104/0334321