Features of polyacrylamide
Polyacrylamide is a water-soluble linear polymer formed by free radical initiation polymerization of acrylamide (AM) monomer, which has good flocculation and can reduce the frictional resistance between liquids, and can be divided into four types according to ionic characteristics: non-ionic, anionic, cationic and amphoteric. Polyacrylamide (PAM) is insoluble in most organic solvents, such as methanol, ethanol, acetone, ether, aliphatic hydrocarbons and aromatic hydrocarbons, except for a few polar organic solvents, such as acetic acid, acrylic acid, chloroacetic acid, ethylene glycol, glycerin, molten urea and formamide. However, these organic solvents have limited solubility and often need to be heated, otherwise they have little application value. It can be dissolved in water in any proportion, and the aqueous solution is a uniform and transparent liquid. The size of the molecular weight has little effect on the solubility, but when the solution concentration is higher than 10%, the polymer with high molecular weight can present a gel-like structure due to the bonding of hydrogen atoms between molecules. High molecular weight solutions are pseudoplastic fluids.
At a suitable low concentration, the polyacrylamide solution can be regarded as a network structure, and the mechanical entanglement and hydrogen bond between the chains together form a network node; At higher concentrations, the PAM solution is gel-like because the solution contains many chain-to-chain contact points. PAM aqueous solution has good compatibility with many organic compounds that can be miscible with water, has good compatibility with electrolytes, and is insensitive to ammonium chloride, calcium sulfate, copper sulfate, potassium hydroxide, sodium carbonate, sodium borate, sodium nitrate, sodium phosphate, sodium sulfate, zinc chloride, boric acid and phosphoric acid.