Polyacrylamide – PAM
Polyacrylamide is relatively stable to heat with its solid only being softened at 220~230 °C and its solution subjecting to significant degradation only at above 110 °C. Polyacrylamide is insoluble in benzene, toluene, xylene, gasoline, kerosene, diesel fuel, but soluble in water. Polyacrylamide can react with alkaline with partial hydrolysis of polyacrylamide. It will have imidization reaction in strongly acidic (pH≤2.5) which will reduce its solubility in water. It can be cross-linked by the poly-nuclear olation complex ion formed between aldehyde (such as formaldehyde) and high metal (such as aluminum, chromium, zirconium, etc.) and is easy to be degraded by the action of the mechanical and (or) oxygen. In oil exploitation, it is mainly used as oil displacement agent, water blocking agent, profile control agent, thickener, drag-reducing agent, water treatment agent.
- Product Content
Solubility in water: upon rapid mechanical stirring, polyacrylamide is easily soluble in cold water form a transparent adhesive solution. Increasing the temperature does not affect its solubility and only affects its dissolution when the concentration is increased to a high viscosity.
Solubility in Other Solvents: polyacrylamide has a over 1% solubility in solvents such as glycerol, ethylene glycol, formaldehyde, acetic acid and lactic acid (these materials may be used as the plasticizer for laminating polyacrylamide). However, it can only be swelled without being dissolved in solvents such as propionic acid, propylene glycol; it is also not soluble in solvent such as acetone and hexane.
Stability: polyacrylamide has a moderate hygroscopic property, if not exposed to position of high temperatures, the powdered polyacrylamide can subject to long-term storage. For liquid polyacrylamide, when its concentration is greater than 17%, it can be stored for more than one year with no significant change in the solution viscosity. In the pH range of 3 to 9, it can maintain a good degree of stability; at high pH, the viscosity will be increased gradually.
Miscibility: in generally used concentration, polyacrylamide has miscibility with most water-soluble natural or synthetic resins, latex systems, and most of the salts. Polyacrylamide can also quickly miscible with non-ionic, cationic and anionic surfactants, though with certain surfactants affecting the viscosity.
Viscosity: The viscosity of polyacrylamide solution has a linear correlation with its molecular weight; in addition, the higher the temperature, the lower the viscosity.
Intrinsic viscosity: the increase of the molecular weight of polyacrylamide will cause increased intrinsic viscosity.
Ion property: the carboxyl group in long-chain yields anionic polyacrylamide; the amino group yields cationic version. Because of the existence of amino group or carboxyl group in the long-chain of polyacrylamide, it is easy for flocculation when encountering aluminum ions.
Retention property: The retention trend of polyacrylamide is similar with that of rosin soap with the former one having a high retention rate.
Toxicity: Polyacrylamide itself is non-toxic, but if it contains polymerized monomers (a double bond), it would be toxic to humans. For this reason, upon the completion of its preparation, a certain amount of sodium bicarbonate should be added to remove residual monomers.