Due to different polymerization conditions, polyacrylic acid can obtain products with various relative molecular weights. Usually, the relative molecular mass common in industry is between several million and several million. Products with different relative molecular weights have different properties and are colorful. Its relative molecular weight is in the range of 2000 ~ 5000, which is suitable for water treatment and used as dispersant.
As a water treatment agent, PAA partially ionizes carboxyl functional groups in aqueous solution, so it has conductivity and is a polyelectrolyte. Carboxylates in polyelectrolyte PAA can chelate alkaline earth metal ions, such as calcium and magnesium, which makes it have anti-scaling effect. Polyelectrolyte PAA can also disperse amorphous materials, such as soil and corrosion, and it is a dispersant.
PAA has calcium carbonate resistance, and 1mg/L PAA can bind 45mg/L calcium ions, and its calcium carbonate resistance is better than that of ordinary vinyl carboxylic acid * * * polymer. PAA is often compounded with corrosion inhibitor as water quality stabilizer.
PAA, a water treatment agent, is a mature industrial product with national standards. Standard number: GB 10533-2000. According to the standard, the appearance of the product is colorless to yellowish transparent liquid, and the solid content is greater than or equal to 30%.
PAA is an acidic substance. Pay attention to labor protection during operation. Avoid contact with skin and eyes, and rinse with plenty of water after contact.
The synthesis of PAA is usually solution polymerization. Mechanism of ionic polymerization. The commonly used solvent is water or isopropanol. At a certain temperature, under the action of initiator and chain transfer agent, acrylic acid can be polymerized to get the product. The main factors affecting the relative molecular weight of polyacrylic acid are solvent, reaction temperature, type and dosage of initiator and chain transfer agent, monomer concentration, feeding method and reaction time. By controlling appropriate conditions, products with satisfactory molecular weight can be obtained.