Classification:

• Non-ionic (NPAM): Contains only amide groups, no charge, suitable for neutral or weakly acidic environments.
• Anionic (APAM): Contains carboxyl (—COO⁻) or sulfonic acid (—SO₃⁻), modified by hydrolysis or copolymerization, suitable for positively charged suspended solids.
• Cationic (CPAM): Contains positively charged groups such as quaternary ammonium (—N⁺(CH₃)₃), often used for negatively charged sewage flocculation.
• Amphoteric PAM: Contains both positive and negative charged groups, suitable for complex water quality.

Physical and chemical properties：

• Solubility: easily soluble in water, the dissolution rate is affected by molecular weight, ion type and particle morphology. Viscous gel is formed at high concentration.
• Viscosity: The viscosity of the aqueous solution is extremely high (positively correlated with the molecular weight), with significant thickening and rheological adjustment capabilities.
• Stability: Strong acid and alkali resistance (pH 3~10), but high temperature (>100°C) or long-term shear force will cause molecular chain degradation.
• Flocculation: Aggregate suspended particles through adsorption bridging and electrical neutralization mechanisms to form large flocs for sedimentation.

Applications：

(1) Water treatment
Wastewater treatment:

Anionic PAM is used for solid-liquid separation of urban sewage and industrial wastewater (such as electroplating, printing and dyeing) to remove suspended matter and heavy metals.

Cationic PAM is used for sludge dehydration to reduce the sludge moisture content (from 98% to 60~80%).

Drinking water treatment: As a coagulant, it is used in combination with aluminum salts/iron salts to reduce the amount of coagulant and improve water quality.

(2) Petroleum industry
Oil displacement agent:

By increasing the viscosity of the injected water (anionic PAM), the sweep efficiency is increased, and it is used in tertiary oil recovery (EOR) of oil fields to increase the recovery rate by 10~30%.

Drilling fluid additive: Control the rheology of drilling fluid and reduce friction resistance.

(3) Papermaking and textiles
Papermaking:

Retention aids (cationic PAM) increase the retention rate of fillers and fibers and reduce white water pollution.

Reinforcement agents improve the tensile strength and burst resistance of paper.

Textiles:

Sizing agents enhance yarn wear resistance; flocculants for dyeing wastewater treatment.

(4) Agriculture and environmental protection
Soil improvement:

Improve soil aggregate structure, reduce soil erosion, and enhance water retention capacity (especially in arid areas).

Sand fixation and ecological restoration: Combined with plant fibers, used for desertification control.

(5) Other fields
Food industry: Sugar clarifier (non-ionic PAM).

Construction: Concrete thickener, reducing cement particle sedimentation.

Cosmetics: Emulsion stabilizer.