Dear all,
In a coating project, I am trying to disperse PMMA micronized particles (around 1µm) in water.
However, because these particles are very hydrophobic, I have difficulties to obtain a stable and fine dispersion.
Moreover, even if the dispersion seems quite stable, when sprayed (with airless sprayer) the particles re-agglomerates during drying of the coating. This re-agglomeration phenomenon is not (or less) visible when the product is applied with a bar applicator.
I have already tried different ways to obtain a fine dispersion :
- thickening of water with clays or polysaccharides
- Addition of surfactant (I have tested SODIUM DIOCTYL SULFOSUCCINATE and Alkyl Polyglucoside)
- Addition of sequestring agent (Sodium Citrate) to prevent interaction of ions with the dispersion
Do you have any idea or know any protocol that could help me in that project ?
Thank you in advance.
Mathieu FIORE
Fiore Mathieu
For better dispersion of PMMA particles in water
1.you can acidify the water and it will better hydrate the ether groups
2.Urea or guanidinium chloride salting agent can be used
This article might be useful
Article Preparation and Characterization of Poly(methyl methacrylate...
can't you reduce surface tension of the water by adding detergent-like substance or salt-agent? Maybe this will work.
Thank you all for your answers.
Yuri Mirgorod, Thank you for your advices.
Classic colloïdal dispersion have a pH around 3-5.
Is it the pH range I should aim for ?
What is the role of urea in a colloïdal dispersion ?
Sourav Roy, Thanks for the article ! I'll try to find valuable information in it.
Przemyslaw Wachulak, I guess that's what I'm doing by adding some surfactants in my formula.
Moreover, if I am above the CMC the surfactant should surround the PMMA particles and prevent agglomeration (which is not a success for the moment).
Fiore Mathieu
Inorganic salts salt out soluble polymers, urea salt шт poorly soluble polymers. Urea hydrotrope.It is alkaline and suitable for your acidic environment. From tobacco waste, we extract nicotine with the help of benzoic acid hydrotrope to inhibit oil tubes when they are purified to acid solutions.
Patent Corrosion inhibitor oil pipe and method for its production
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