Polyacrylamide (abbreviated as PAM) is a linear polymer formed by the polymerization of acrylamide monomers, with the chemical formula $(C_3{H}_{5}NO{)}_n$(C3H5NO)n.

1. Basic Properties

• Physical Properties: White solid powder or gel, odorless, soluble in water, insoluble in most organic solvents.

• Chemical Properties: Contains amide groups (-CONH?) on the molecular chain; other functional groups (such as carboxyl, sulfonic acid groups, etc.) can be introduced through modification to form anionic, cationic, or non-ionic PAM.

2. Classification

Based on charge characteristics, PAM can be classified into:

• Non-ionic (NPAM): Contains only amide groups, suitable for neutral or weakly acidic environments.

• Anionic (APAM): Contains negatively charged groups such as carboxyl groups (-COO?), suitable for positively charged suspended particles.

• Cationic (CPAM): Contains positively charged groups such as quaternary ammonium salts, commonly used for treating negatively charged organic matter (e.g., sludge dewatering).

• Amphoteric: Contains both positively and negatively charged groups, adaptable to more complex systems.

3. Main Applications

(1) Water Treatment

• Flocculant: Aggregates and settles suspended particles through charge neutralization and bridging, used in sewage and industrial wastewater treatment.

• Sludge Dewatering: Cationic PAM improves the filterability of sludge and reduces water content.

(2) Petroleum Extraction

• Oil Displacement Agent: Increases the viscosity of injected water and enhances crude oil recovery (tertiary oil recovery).

• Drilling Fluid Additive: Adjusts the rheology and lubricity of drilling fluids.

(3) Paper Industry

• Reinforcing Agent: Improves paper strength.

• Retention Aid: Reduces the loss of fibers and fillers.

(4) Other Fields

• Agriculture: Soil water-retaining agent, seed coating.

• Textile: Sizing agent, printing and dyeing wastewater treatment.

• Construction: Concrete thickener, anti-seepage materials.