What CAS 9003-05-8 Identifies
CAS 9003-05-8 is the CAS registry number for polyacrylamide, normally shortened to PAM. It is a linear, water-soluble polymer built from acrylamide repeat units, and it belongs to the family of synthetic water-soluble polymers that underpin most modern solid-liquid separation. The registry number describes a polymer family rather than one single molecule, so two commercial materials that both answer to CAS 9003-05-8 can behave very differently in a plant. Molecular weight, charge type and charge density are the variables that decide which grade suits a given duty.
Dry polyacrylamide is traded as a white granular powder or as small beads. Water-treatment grades typically contain at least 90 percent solids, hold an insoluble fraction of no more than 0.2 percent and keep residual acrylamide monomer at or below 0.05 percent. Liquid forms are also available and are subcategorised into solution polymers and emulsion polymers; they dissolve faster on site but carry a higher freight cost per active tonne.
The Three Commercial Charge Types
Anionic polyacrylamide, APAM - carries carboxylate groups introduced by partial hydrolysis, with a typical degree of hydrolysis of 5 to 35 percent and molecular weights from about 3 to 25 million. It is used where negatively charged suspensions, mineral tailings and metal hydroxide flocs must be bridged into fast-settling agglomerates.
Cationic polyacrylamide, CPAM - carries amine or quaternary ammonium groups and is described by cationicity rather than hydrolysis. It neutralises negatively charged organic colloids and is the workhorse of sludge conditioning and paper retention.
Nonionic polyacrylamide, NPAM - stays close to neutral, usually 5 to 15 percent hydrolysis, and is chosen for acidic circuits, low-turbidity waters and thickening duties where charge interaction must be minimised.
Typical Technical Specifications
| Item | Anionic | Nonionic | Cationic |
|---|---|---|---|
| Appearance | White granule or powder | White granule or powder | White granule or powder |
| Particle size | Finer than 40 mesh | Finer than 40 mesh | Finer than 40 mesh |
| Molecular weight, ten thousand | 300 to 2500 | 300 to 1600 | 300 to 1600 |
| Degree of hydrolysis, percent | 5 to 35 | 5 to 15 | 10 to 80 |
| Solid content, percent | at least 90 | at least 90 | at least 90 |
| Insoluble content, percent | at most 0.2 | at most 0.2 | at most 0.2 |
| Residual monomer, percent | at most 0.05 | at most 0.05 | at most 0.05 |
Powder grades are packed in 25 kg kraft bags with an inner liner, or in 750 kg jumbo bags for bulk users. Water-treatment grades are commonly supplied against the requirements of GB/T 17514, which sets the framework for polyacrylamide used as a water treatment agent, while drinking-water and food-contact duties may carry additional national requirements in the destination market.
Where Polyacrylamide Is Used
Because PAM can be tailored during manufacture, it appears in a very wide set of industrial operations. The list below reflects the sectors where tonnage is concentrated.
Water and wastewater treatment - primary clarification, coagulation and flocculation, sludge thickening and dewatering, and industrial effluent polishing.
Paper making - retention and drainage aids, dry strength resins and process-water clarification in the stock preparation loop.
Petroleum - drilling fluid viscosity control, fluid loss reduction, profile modification and polymer flooding for enhanced oil recovery, plus drag reduction in pipelines.
Mining, coal and metallurgy - tailings settling, ore dressing, thickening of concentrates and filtration of fine slimes.
Textile and geology - sizing and finishing baths, warp sizing, and soil stabilisation or erosion control.
Construction - cement and mortar additives, tile adhesive rheology control and construction slurry treatment.
Dissolution, Dosing and Storage Practice
Powder polymer must be wetted particle by particle, otherwise lumps form that never dissolve. A stock solution of 0.1 to 0.5 percent by weight is prepared with gentle, low-shear agitation for 40 to 60 minutes; the aged solution is best used within 24 hours, and within 48 hours at most, because viscosity and flocculating power fade as the polymer chain degrades. The working dose is fixed by jar test or by plant trial rather than by rule of thumb, since solids load, pH and shear all shift the optimum. Overdosing restabilises the suspension and reverses settling.
Dry powder is hygroscopic and should be stored in a cool, dry, shaded warehouse away from oxidising agents, with bags kept sealed. Grades are not interchangeable between duties: moving from an anionic to a cationic product changes the chemistry of the whole treatment train.
Frequently Asked Questions
Q: Is CAS 9003-05-8 the same as PAM?
Yes. CAS 9003-05-8 is the registry number for polyacrylamide, the polymer widely traded under the abbreviation PAM, and it covers anionic, cationic and nonionic variants.
Q: Which polyacrylamide is best for sludge dewatering?
Cationic polyacrylamide is normally used for organic sludge, with charge density matched to the sludge type; digested sludge generally calls for a higher cationicity than raw mixed sludge.
Q: Is polyacrylamide supplied as powder or liquid?
Both forms are commercial. Powder offers the highest active content and lowest freight cost, while solution and emulsion polymers dissolve faster and suit automated dosing systems.
Q: What affects the performance of a PAM grade?
Molecular weight controls bridging and floc size, charge type and charge density control colloid neutralisation, and the degree of hydrolysis fine-tunes the balance between the two.
Q: How should polyacrylamide powder be stored?
Keep bags sealed in a cool, dry, dark warehouse, avoid high humidity and direct sunlight, and use stock on a first-in first-out basis to limit ageing.
Q: Can polyacrylamide be used as a thickener?
Yes. High molecular weight grades raise the viscosity of aqueous systems at low addition rates, which is why PAM is used in textile printing pastes, drilling fluids and some construction formulations.
