Polyacrylamide (PAM) is a synthetic polymer derived from acrylamide, a monomer with the chemical formula C₃H₅NO. It is commonly used in a variety of industrial, agricultural, and scientific applications due to its versatile properties.

Chemical Composition and Structure:
Polyacrylamide is composed of repeating units of acrylamide, a compound with the formula C₃H₅NO. The polymer is formed through the polymerization of acrylamide monomers, resulting in a long chain molecule. The chemical structure of polyacrylamide consists of a backbone of carbon atoms with amide groups (–CONH₂) attached, which contributes to its hydrophilic nature. The polymer can be classified into different types based on its degree of hydrolysis and the presence of additional functional groups, including non-ionic, anionic, cationic, and amphoteric variants.

Physical Properties:
Polyacrylamide is a white, odorless powder that is soluble in water. Its solubility is highly dependent on the degree of polymerization and the presence of ionic groups. It forms a viscous, transparent solution when dissolved in water. The polymer exhibits high molecular weight, which contributes to its gel-forming ability. Polyacrylamide is known for its high degree of flexibility, excellent water retention, and its ability to form a gel-like substance under certain conditions. It has a wide range of viscosities and can be tailored to specific applications through chemical modifications.

Production Process:
The production of polyacrylamide involves the polymerization of acrylamide monomers, typically using a free-radical initiator. The process is carried out in aqueous solutions or emulsions, and the polymerization can be controlled to produce various molecular weights and properties. The reaction usually requires the presence of catalysts, such as ammonium persulfate or azo compounds, and can be performed under mild conditions. After polymerization, the resulting polyacrylamide is purified and dried to obtain the final product. In some cases, the polymer is cross-linked to enhance its structural integrity.

Applications:
Polyacrylamide has a wide range of applications across different industries:

Water Treatment: It is used as a flocculant in water treatment processes to remove suspended particles and clarify water.
Agriculture: Polyacrylamide is applied as a soil conditioner to improve soil structure, reduce erosion, and enhance water retention.
Mining: It serves as a flocculant in mineral processing to aid in the separation of ores from waste materials.
Cosmetics: In the cosmetic industry, polyacrylamide is used in formulations as a thickening agent and stabilizer.
Pharmaceuticals: It is employed in drug delivery systems and as a medium for electrophoresis in laboratory research.
Oil Recovery: Polyacrylamide is used in enhanced oil recovery techniques to increase oil extraction efficiency.

Environmental and Safety Considerations:
Polyacrylamide is generally considered to have a low environmental impact when used properly. However, the acrylamide monomer, which can be toxic, poses potential risks if not polymerized completely. Proper handling and use of polyacrylamide are essential to minimize exposure to acrylamide. The polymer itself is typically not harmful to the environment, but its use in large quantities should be managed to avoid possible ecological impacts. Safety guidelines for handling polyacrylamide include using protective equipment and following proper disposal procedures to prevent contamination.

Cosmetic safety

Restricted cosmetic ingredient as III/66 a Relevant Item in the Annexes of the European Cosmetics Regulation 1223/2009. Substance or ingredient reported: Polyacrylamides. Maximum concentration in ready for use preparation: Body leave-on products, maximum residual acrylamide content 0.1mg/kg. Other products, maximum residual acrylamide content 0.5mg/kg.

INCI:


Antistatic agent. Static electricity build-up has a direct influence on products and causes electrostatic adsorption. The antistatic ingredient reduces static build-up and surface resistivity on the surface of the skin and hair.

Binder agent. Ingredient that is used in cosmetic, food and pharmaceutical products as an anti-caking agent with the function of making the product in which it is incorporated silky, compact and homogenous. The binder, either natural such as mucilage, gums and starches or chemical, may be in the form of a powder or liquid.

Film-forming agent. It produces, upon application, a very thin continuous film with an optimal balance of cohesion, adhesion and stickiness on skin, hair or nails to counteract or limit damage from external phenomena such as chemicals, UV rays and pollution.
Synonyms:

CAS: 2594446