Polyacrylamide (PAM) is a polymer with the chemical formula CH2CHCONH2 composed of acrylamide monomers that are bonded together at the end. This compound is formed by the radical polymerization of the acrylamide monomer. Polyacrylamide is one of the most widely used water-soluble polymer species with many free amide groups in its molecular structure.
One of the most common uses of polyacrylamide is to float solids in the liquid. This process is used for water treatment and for things like paper making and page printing.
Physical and chemical properties:
Polyacrylamide is a solid glass at room temperature and due to differences in production methods, this product can be produced in the form of white powder, transparent granules, and laminates. Polyacrylamide has good thermal stability and is soluble in water. The aqueous solution of this compound is clear and transparent, and its viscosity increases with the increasing molecular weight of the polymer.
|Molecular Weight||71.08 g/mol|
|Appearance||white powders and transparent grains|
|Melting point||84.5 °C|
|Solubility in water||2.04 kg/L 25 °C|
|Solubility||Insoluble in organic solvents|
|color||White to faintly yellow|
|Chemical Structure Depiction|
Stability of Polyacrylamide:
One of the most important properties of polyacrylamide is its ability to remain stable as a powder for a long time. In fact, moisture absorption in this polymer is moderate. If the polymer is soluble and its concentration exceeds 17%, it can be stored for more than one year without changing its viscosity.
Polyacrylamide has very good stability at pH 3 to 9. if it is exposed to higher pH, its viscosity will gradually increase.
Classification of Polyacrylamides:
Polyacrylamides can be classified into different directions such as chain length (molecular weight) and charge. PAM has 4 types which are neutral, anionic, cationic, and nonionic. Cationic polyacrylamides have the ability to adsorb negatively charged particles, and anionics absorb positive particles, and nonionic (no charges) are used under certain conditions (mostly in the mining sector).
To produce this material, two methods of solution and emulsion (sedimentation) are used.
- Solution production is used to produce this material. In the solution of water and monomer with a concentration of 5-20% in the presence of redox catalyst, an aqueous solution is used, which is usually potassium persulfate and sodium bisulfite. The product is unstable and must be dried and powdered after production.
- In the sedimentation method; in addition to water, a solvent such as acetone or alcohol is also used. For this reason, after polymerization, the water-soluble polymer in this solvent is deposited as a polymer sludge and separated by centrifugation and dried using acetone.
Applications and Uses of PAM:
Polyacrylamide is widely used in many industrial applications and for chemical and environmental purposes.
- In the paper industry, polyacrylamide plays an important role as a fiber preservative and pigment retention on paper fibers.
- Polyacrylamide is an acrylic resin that has the unique property of solubility in water. This material is used in industrial and municipal wastewater.
- This organic polymer is used in cosmetics to stabilize products and ingredients.
- This compound is also used to reduce soil erosion.
- The gel of this substance is used for the electrophoretic separation of small or medium-sized proteins.
Application of PAM in Water treatment:
Polyacrylamides have many applications in a wide range of industrial processes, but one of the most important main applications is for coagulation or flocculation of solids in liquid in municipal and industrial wastewater.
This polymer increases the viscosity of water and causes particles in the water to clot.
The use of polyacrylamides increases efficiency and reduces treatment costs, while organic coagulants can be used in certain industries, for example, to remove paint from effluents. These chemicals increase the sedimentation rate of suspended solids and increase the size and density of sediments, as well as increase the filtration and separation efficiency and improve the quality and reduce the final turbidity.
Applications of Polyacrylamide in Agriculture:
This polymer is used in agriculture to increase aeration and reduce soil density, improve irrigation and deep rooting, and increase the strength and appearance of crops. It also helps the agricultural sector by reducing water requirements, reducing soil erosion and plant maintenance costs.
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It is used as a binder and stabilizer in lotions and cosmetics. In Europe, the use of this substance is used in permissible concentrations. It is used in products such as facial moisturizers, anti-aging products, lotions, hair products, sunscreens, etc.
Inhalation: May be harmful if inhaled. May cause respiratory tract irritation.
- Skin: It May be harmful if absorbed through the skin. May cause skin irritation.
- Eyes: May cause eye irritation.
- Ingestion: It May be harmful if swallowed.
Some research has shown that this substance affects the nervous system. The use of this substance in high doses causes cancer in animals. More research is needed to prove the health effects of this substance.
- Skin Contact: Immediately flush skin with water.
- Inhalation: move the person to the fresh air.
- Eye Contact: Rinse eyes with water for at least 15-20 minutes.
- Ingestion: Do not induce vomiting. Get medical aid immediately. Call a poison control center.
Packing and storage:
Keep the container tightly closed in a dry and well-ventilated place. keep away from heat and direct sunlight.