Sodium naphthalene sulfonate formaldehyde condensate, commonly called dispersant NNO, is an anionic, water-soluble condensation polymer. It is used as a dispersant in dyes, pigments, ceramics, agrochemical suspensions and concrete admixtures. Green Agrochem supplies it as a powder in several grades. This page explains what the product is chemically, how it differs from simple sodium naphthalene sulfonate, how it stabilizes particles, and how to read the grade data.
SNS and NNO are not the same substance
“Sodium naphthalene sulfonate” (SNS) is a family name, and the products in it behave very differently:
| Sodium naphthalene sulfonate (monomer) | NNO (formaldehyde condensate) | |
|---|---|---|
| Structure | A single sulfonated naphthalene ring, sodium salt | Naphthalene sulfonate units linked by methylene (–CH2–) bridges into oligomers and polymers |
| Typical role | Hydrotrope, wetting or intermediate | Dispersant and colloid-protective agent; also a concrete water reducer (SNF/PNS family) |
| Why it matters | Dispersing power comes from the condensed polymer adsorbing on particle surfaces. A monomer does not do the same job, and a single catalogue formula (for example C21H14Na2O6S2) describes only one short oligomer, not the commercial mixture. | |
Green Agrochem’s NNO safety data sheets identify the product as CAS 9084-06-4, with the synonyms sodium naphthalene sulfonate formaldehyde condensate and sodium polynaphthalene sulfonate. Other suppliers may use other identifiers, so confirm identity from the SDS of the exact product you buy.
How NNO is made, and why it matters for the spec
- Sulfonation: naphthalene is sulfonated with sulfuric acid. High-temperature sulfonation favours the 2-naphthalenesulfonic acid isomer.
- Condensation: the sulfonic acid is condensed with formaldehyde, linking rings through methylene bridges. The degree of condensation, meaning chain length and molecular-weight distribution, drives dispersing performance.
- Neutralization and drying: the acid is neutralized with sodium hydroxide and spray-dried to powder. Residual sulfuric acid becomes sodium sulphate.
That is why the specifications differ. Sodium sulphate is inactive filler and electrolyte, so a high-sulphate grade carries less active polymer per kilogram and adds salt to the system. Low-impurity grades also control residual monomers such as free naphthalene and free formaldehyde.
Grade data
Typical values from Green Agrochem’s current TDS documents. The shipment COA reports batch results.
| Parameter | GAC-NNO-A | GAC-NNO-B | GAC-NNO-C | GAC-NNO-HP |
|---|---|---|---|---|
| Appearance | Brown powder | Brown powder | Brown powder | Powder |
| Content / solids | 95% min | 92% min | 95% min | Solid content 93% min |
| Dispersing power (vs standard) | 95% min | 90% min | 95% min | Not stated |
| Sodium sulphate | 5% max | 18% max | 22% max | SO4 around 3.0% |
| pH | 7–9 (1%) | 7–9 (1%) | 7–9 (1%) | 7.0–9.0 (2%) |
| Calcium & magnesium | 0.4% max | 0.4% max | 0.4% max | Not stated |
| Water-insoluble matter | 0.05% | 0.05% | 0.05% | Not stated |
| Free naphthalene / formaldehyde / quinoline | Not stated | Not stated | Not stated | < 5 / < 50 / < 200 ppm |
Choose low-sulphate grades (A, High-Purity) where electrolyte sensitivity, colour stability or salt bloom matter, for example in dye standardization, pigment concentrates and ceramics. Higher-sulphate grades can be economical where salt is tolerated. Dispersing power is measured against a standard product, so request the method before comparing suppliers.
How NNO disperses particles
- Adsorption: the aromatic naphthalene segments adsorb on hydrophobic surfaces such as dyes, organic pigments and carbon black, and on mineral surfaces.
- Electrostatic stabilization: the sulfonate groups give particles a negative charge, so they repel one another and resist flocculation.
- Deagglomeration support: during milling or high-shear mixing, adsorbed NNO helps keep newly separated particles from re-agglomerating.
NNO acts mainly by electrostatic stabilization. It is therefore more sensitive to hardness ions, high salt and cationic components than steric dispersants such as polycarboxylates, and should not be assumed to behave like them. It is a dispersant, not a UV stabilizer or lightfastness additive. Weathering performance depends on the full formulation and pigment choice. The NNO TDS also notes an affinity for protein and polyamide fibres (wool, silk, nylon) and little affinity for cotton or linen, which matters in textile processes.
Typical applications
| Application | What NNO does | Key test | Guide |
|---|---|---|---|
| Dye grinding and dyeing | Keeps disperse and vat dye particles dispersed | Particle size, filtration, deposits, shade | NNO for dye processing |
| Aqueous pigment dispersions | Wetting support and electrostatic stabilization | Viscosity, colour strength, storage stability | NNO pigment dispersions |
| Agrochemical suspensions (SC, WP, WG) | Suspends active ingredient particles | Suspensibility, dispersion, storage | NNO in pesticide formulations |
| Ceramics | Deflocculates clay and mineral slips | Slip viscosity, solids loading | – |
| Concrete | Water reduction (naphthalene superplasticizer) | Slump, water reduction, strength | Construction grades: LigninCorp |
Performance depends on grade, dosage and the complete formulation. Evaluate in the target system rather than from the chemical name. The High-Purity TDS gives supplier starting ranges for its stated uses: 0.5–1.2% by weight of cementitious material in concrete, 2–5% on total dry solids for pigment and dyestuff dispersion, and 0.3–0.8% of dry gypsum in wallboard. Treat these as starting trial ranges for that grade, not universal dosages.
Statements in older content and their status
| Statement | Status |
|---|---|
| “Dark brown to black viscous liquid” | Not the form of the current grades, which are powders |
| Dissolves and stays stable in any water, acid, alkali, salt or heat; never foams | Too broad; test the actual water, pH, electrolytes and temperature |
| Protects pigments from UV and improves lightfastness | Not a function of the dispersant |
| Non-toxic, non-flammable, safe | Use the current SDS; dust handling and exposure controls apply |
| 0.5–1.5 g/L, 3–5 g/L, 0.5–5 g/L dye-bath figures | No grade or basis; not current recommendations |
Safety and documents
Toxicity, handling precautions and regulatory status depend on grade and destination market. Request the current SDS, TDS and a representative COA for the exact grade, and check the inventory listings that apply in your market. Where residual monomers matter, specify free naphthalene and free formaldehyde limits; the High-Purity grade states them.
For grade selection or samples, send the application, current dispersant, water quality, test method and destination to info@greenagrochem.com. Product page: Dispersant NNO.