Regulation of the aggregate stability for binary polymer-mineral dispersions

Abstract

ABSTRACT: Introduction. In the binary dispersed systems of different origins (mineral and polymer) with particles differing in size by an order of magnitude, heterocoagulation is observed. Regulation of the aggregate stability is crucial in controlling the properties of functional dispersed materials based on such mixed dispersions. This study focuses on the investigation of waterborne mono and binary dispersions of polyvinyl acetate, Portland cement, and chalk by eans of static laser light scattering and optical microscopy. Materials and research methods. In order to investigate the action mechanism of the FF modifier based on phloroglucinol furfural oligomers as disperse phase we used chalk (CaCO3 – chalk dispersed technical MTD-2, LLC “Technostroy”, Kopanishchenskoe deposit), Portland cement CEM I 42.5N (JSC “Belgorod Cement”), and polyvinyl acetate (LLC “Kuban-Polymer”). Particle distribution and the aggregate stability of dispersions were studied with an Analysette 22 NanoTecplus device. The particle sizes were determined by optical microscopy with “Axio.Scope.A.1” microscope, and the adsorption of oligomers on the particles of dispersions was analyzed using a UV spectrometer (SPECORD UV). Results and discussion. It has been established that the phloroglucinol furfural modifier contributes to the stabilization of binary polymer-mineral dispersions. Integral and differential distribution curves of polymeric particles have been obtained in a wide range of 0.01–2100 µm. Research has shown the regularity of the modal diameter reduction of adsorption-modified particles with a transition from a narrow to a wider distribution with the absence of large coagulums. Conclusion. The hypothesis has been proposed that the adsorption-solvation factor of aggregate stability makes a significant contribution to the aggregate stability of binary polymer-mineral dispersions. The impact of this factor is different for mono-mineral and binary polymer-mineral dispersions and depends on the hydrophilicity of the surface, increases with the transition from mineral surface to the polymer surface as the Hamaker constant increases

Keywords

• : binary dispersions
• aggregate stability
• adsorption
• oligomers
• nanomodification
• differential distribution
• modal particle radius