Preparation of hydrophobic agent
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Hello everyone, is there anyone in the laboratory who makes hydrophobic agents, which are used in architectural coatings, mainly for exterior walls? Please give me some advice! I can't find a lot of literature. I hope someone can tell me about the raw materials. This is my research topic and I don't know how to start. Please give me some advice!
Water-based hydrophobic agent is a mixed compound that is dispersed in water to form a stable dispersion after scientific and technological surface modification. When added to the paint, it can form a special water-resistant structure (change the contact angle) on the film-forming surface of the paint, making the surface extremely hydrophobic, hydrophobic, waterproof, and improving the odor-masking effect. At the same time, it does not affect the breathability of the coating film. ； It not only avoids the poor recoatability of silicone hydrophobic materials, but also avoids the poor breathability of other hydrophobic agents. The coating has good properties such as lotus leaf double hydrophobicity, self-cleaning, hydrophobicity, waterproofness, stain resistance, and scrub resistance. This product is added during the paint mixing process. The recommended dosage is 1%-6%. The specific situation can be determined according to the needs of the user. Shape Opaque white liquid Particle size, nm 30-50 Solid content, % 38±1 PH value 7±1 Viscosity, mPa.s 4500±500 (SS-01 type) 2500±500 (SS-02, 02A type) Storage stability for 12 months. The effect of non-polar groups (such as hydrocarbon chains) in aqueous solution coming closer and associating with each other is the so-called "hydrophobic effect" or "hydrophobic effect". The result of hydrophobic interaction is expressed as: In aqueous media, there is a significant attraction between non-polar molecules or groups (i.e., "hydrophobic" molecules or groups). However, "hydrophobic" means that there is repulsion between such non-polar molecules (or groups) and water molecules, and there is no van der Waals attraction. ； Rather, it shows that in such a system where non-polar molecules or groups are together with water, there is a thermal ionic tendency of the non-polar molecules or groups themselves to associate with themselves and escape from the water medium. Only by increasing the contact angle from Л/2>θ>0 to Л>θ>Л/2 can the coating exhibit a water-repellent effect similar to that of a lotus leaf.
Hydrophobic materials are mainly studied based on their mechanisms. They cannot have hydrophilic groups. It is best if the groups are all hydrophobic. I haven’t done it before, but I want to start from this aspect.