Adipic Acid CAS 124-04-9
Chelora Chemicals supplies nylon-grade and technical-grade adipic acid to polyamide, polyurethane, plasticiser and food users worldwide. Every consignment leaves with a batch-specific COA covering purity, colour, moisture and metals, the current SDS and full export documentation.
Also known as: Hexanedioic acid · 1,4-Butanedicarboxylic acid · ADA · Adipinic acid
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Price, lead time and a sample COA for Adipic Acid, usually within one working day. We ship worldwide.
Request a Quote Email the DeskDocumentation
- Batch-specific COA (purity, colour, moisture, metals)
- Safety Data Sheet (SDS)
- Transport and export documents
- Third-party inspection on request
- Certificate of origin
What is Adipic Acid?
Adipic acid is a six-carbon dicarboxylic acid, C₆H₁₀O₄, a white crystalline powder melting at about 152 °C with a mildly acidic taste. It is modestly soluble in water and freely soluble in alcohols.
Its dominant use is nylon 66, where it reacts with hexamethylenediamine to form the nylon salt that polymerises into the polyamide used for fibre, tyre cord and engineering resin.
Beyond nylon, adipic acid goes into polyurethane polyester polyols, adipate plasticisers, powder coating resins and food acidulation, with smaller volumes in pharmaceutical and specialty applications.
Conventional production generates nitrous oxide, a potent greenhouse gas, and abatement of that emission has become a significant part of plant operation and of producers' carbon reporting.
Why Adipic Acid specifically
- A linear six-carbon diacid. Gives nylon 66 its regular chain structure, high melting point and strength.
- Two reactive carboxyls. Forms salts, esters and polyesters readily with diamines and diols.
- Low-temperature flexibility. Adipate esters stay flexible in cold, which is why they are used where phthalates would stiffen.
- Food-acceptable. Approved as a food acidulant, giving a tart flavour profile distinct from citric acid.
How Adipic Acid is Manufactured
Adipic acid is made by nitric acid oxidation of a cyclohexanol and cyclohexanone mixture, with N₂O abatement as a critical part of modern plants.
- Cyclohexane oxidation. Air oxidation of cyclohexane gives the KA oil mixture of cyclohexanol and cyclohexanone.
- Alternative KA routes. Phenol hydrogenation or cyclohexene hydration supply KA oil in some plants.
- Nitric acid oxidation. KA oil is oxidised with nitric acid over a copper-vanadium catalyst to adipic acid.
- Nitrous oxide abatement. The reaction generates N₂O, a potent greenhouse gas; catalytic or thermal abatement is standard in modern plants.
- Crystallisation. Adipic acid is crystallised from the reaction liquor, with mother liquor recycled.
- Drying and sizing. Centrifuging, drying and classification produce the free-flowing crystalline product.
Typical Commercial Specification
Figures below are representative of commercial nylon-grade adipic acid. Food and technical grades carry different limits — tell us the use and we will send the matching sheet.
| Parameter | Typical Value |
|---|---|
| Appearance | White crystalline powder, free flowing |
| Adipic acid purity | 99.7% min by weight |
| Colour (APHA, 10% solution) | 10 max |
| Moisture | 0.2% max |
| Ash | To grade, typically 10 ppm max |
| Iron | To grade, typically 1 ppm max |
| Nitric acid and nitrates | To grade, typically 10 ppm max |
| Other dibasic acids | To grade, typically 0.1% max |
| Melting point | 151 to 154 °C |
| Heavy metals | To grade, typically 5 ppm max |
Physical & Chemical Properties
| Property | Value |
|---|---|
| Chemical formula | C₆H₁₀O₄ (HOOC(CH₂)₄COOH) |
| Molecular weight | 146.14 g/mol |
| Appearance | White crystalline powder, odourless, slightly acidic taste |
| Melting point | 152 °C |
| Boiling point | 337 °C with decomposition |
| Flash point | About 196 °C |
| Bulk density | About 0.6 to 0.8 g/cm³ |
| Solubility in water | About 24 g/L at 20 °C, rising sharply with temperature |
| pKa | 4.43 and 5.41 |
| Dust explosion | Combustible dust; minimum ignition energy is low enough to require control |
| Incompatibilities | Strong oxidisers, strong bases, ammonia |
Behaviour in the process
Adipic acid is a stable solid, and the handling issues are dust, moisture and caking:
- Combustible dust. Fine adipic acid dust forms explosible clouds; ignition control and extraction are required.
- Mildly hygroscopic. Picks up moisture in humid storage, which causes caking and affects salt stoichiometry.
- Dissolves readily when hot. Solubility rises sharply with temperature, which is used in nylon salt preparation.
- Mildly corrosive in solution. Aqueous solutions attack carbon steel; stainless is used in salt preparation.
Adipic Acid Grades and Alternatives
Adipic acid is bought by grade, and the differences are colour, metals and particle size rather than bulk purity.
| Material | Origin / type | When it is the right choice |
|---|---|---|
| Nylon-grade adipic acid | 99.7%+, low metals and colour | Nylon 66 salt and polyamide production |
| Technical-grade adipic acid | 99.5%+ | Polyester polyols, plasticisers and powder coatings |
| Food-grade adipic acid | FCC compliant | Food acidulant and gelling applications |
| Sebacic acid | C₁₀ diacid, CAS 111-20-6 | Where longer chain length and more flexibility are wanted |
| Dodecanedioic acid | C₁₂ diacid, CAS 693-23-2 | Specialty polyamides and powder coatings |
Stated plainly: for nylon 66 there is no substitute for adipic acid. In polyols and plasticisers, longer-chain diacids give more flexibility at higher cost, and the choice is a performance decision.
Industries We Supply Adipic Acid To
Nylon dominates, with polyurethanes, plasticisers and food applications behind it.
Where Adipic Acid is Used
Nylon 66 takes the majority of adipic acid, with polyester polyols and plasticisers the main non-nylon uses.
In nylon 66 manufacture
Adipic acid is neutralised with hexamethylenediamine in water to form a precisely balanced nylon salt solution, which is then concentrated and polymerised under pressure. The stoichiometric balance determines achievable molecular weight, so acid purity and moisture content both feed directly into salt pH control — and metals carried into the salt show up as polymer colour.
In polyester polyols
Adipic acid is esterified with diols such as MPG, diethylene glycol or butanediol to make polyester polyols for polyurethane elastomers, flexible foam and adhesives. These polyols give better mechanical properties and oil resistance than polyether equivalents, at the cost of poorer hydrolytic stability.
Need a specific grade, purity and packing format?
Tell us the grade, the colour and metals limits your polymerisation requires, the packing format you can receive and the annual quantity. We will come back with a price, a lead time, a sample COA and the full documentation set.
Quality Control & Testing
Every lot is released against a batch-specific Certificate of Analysis, with colour and metals reported alongside purity because they determine polymer appearance.
- Adipic acid purity — by titration and chromatography, the primary grade measure.
- Colour in solution — by APHA, the practical predictor of polymer colour.
- Moisture — measured because it affects salt stoichiometry and caking.
- Iron and heavy metals — reported in ppm because they catalyse polymer degradation.
- Nitrates and other dibasic acids — measured as the characteristic process impurities.
- Melting point and particle size — confirming identity and handling behaviour.
Common Process Problems & Likely Causes
When adipic acid causes trouble, it is usually colour, metals, moisture or dust. This table is the shortcut our technical desk works through before anyone opens a complaint file.
| Symptom | Likely cause | What to check |
|---|---|---|
| Yellow colour in nylon polymer | Iron or other metals in the acid | Iron and heavy metals figures on the COA |
| Nylon salt pH out of balance | Acid purity or moisture variation | Purity and moisture results, salt dosing calibration |
| Molecular weight below target | Stoichiometric imbalance in the salt | Purity, other dibasic acids and HMDA dosing |
| Caking in bags or silos | Moisture pick-up in humid storage | Moisture result and warehouse humidity |
| Dust accumulation and ignition risk | Fine particles generated in conveying | Dust extraction, earthing and housekeeping |
| Polyol colour or acid value off | Colour bodies or nitrates in the acid | Colour and nitrate figures |
Packaging, Storage & Shipping
- Standard packing. 25 kg bags, 500 to 1000 kg jumbo bags and bulk containers.
- Storage. Cool, dry, covered warehousing on pallets, away from moisture and direct sunlight.
- Dust control. Adipic acid dust is combustible; use earthed, enclosed conveying with extraction and good housekeeping.
- Moisture control. Keep bags sealed. Moisture pick-up causes caking and shifts salt stoichiometry.
- Material compatibility. Stainless steel for solutions; aqueous adipic acid attacks carbon steel.
- Segregation. Keep apart from strong oxidisers, bases and ammonia.
- Shelf life. Typically 24 months in sealed bags in dry storage. Caking is the limiting factor.
- Transport classification. Not classified as dangerous goods for transport.
Hazards & Safe Handling
Adipic acid has low toxicity and is not classified as dangerous goods, but it causes serious eye irritation and its dust is combustible, which is the principal workplace hazard.
- Eye irritation. Causes serious eye irritation on contact with dust or solution. Use goggles during handling.
- Combustible dust. Fine dust forms explosible clouds. Control ignition sources, earth equipment and maintain housekeeping.
- Low systemic toxicity. Approved as a food additive; not acutely toxic in normal industrial handling.
- Respiratory irritation. Dust inhalation irritates the respiratory tract; use extraction and dust masks.
- Skin contact. Mild irritant on prolonged contact; use gloves.
- Hot solutions. Nylon salt preparation runs hot; thermal burns are the realistic process hazard.
- Environment. Readily biodegradable; contain spills to prevent pH depression in watercourses.
Regulatory & Compliance Notes
Adipic acid is unregulated for transport with food and pharmaceutical standards where applicable, and increasing attention to production emissions. The notes below are orientation rather than legal advice.
- GHS classification. Serious eye irritation Category 2 in most classifications; otherwise not hazardous.
- Transport. Not classified as dangerous goods. Standard packaged and bulk cargo documentation applies.
- Food additive status. Approved as a food acidulant in the EU as E355 and in the US and other markets, with FCC specifications applying.
- Nitrous oxide emissions. Adipic acid production is a significant historical N₂O source; abatement is now standard and features in customers' supply chain carbon reporting.
- Dust explosion regulation. Handling systems fall under ATEX, NFPA or equivalent combustible dust requirements.
- REACH and inventories. Registered under EU REACH and listed on the major chemical inventories.
We Supply Adipic Acid Worldwide
Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Adipic Acid from India and from partner sources to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation, transport paperwork and freight so the material arrives ready to use.
- Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
- Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other ports arranged where routing and cargo rules allow.
- Documentation. Commercial invoice, packing list, certificate of origin, COA, SDS and the transport declaration issued as a complete set.
- Flexible volumes. From a pallet of bagged product up to repeat bulk shipments on a supply contract.
- Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.
Buying Adipic Acid from Chelora
We are an independent sourcing and supply partner. For adipic acid that means settling three things at enquiry: the grade and metals limits your polymerisation requires, the packing and dust-handling arrangements at your site, and whether N₂O abatement documentation is needed for your carbon reporting.
- Documentation on every lot. Batch-specific COA (purity, colour, moisture, metals), plus SDS and the full transport paperwork.
- Analysis before commitment. Representative analysis shared ahead of a commercial order so your lab can qualify the material.
- Quantities. From a pallet of bagged product through to full bulk shipments on contract supply.
- Grade matching. Nylon, technical or food grade, to the colour, metals and moisture limits your process requires.
- Inspection. Independent third-party inspection available at loading when the contract requires it.
- Related products. Nylon 66, Caprolactam, Nitric Acid and other feedstocks alongside Adipic Acid from one supplier.
How ordering works
- Send the enquiry. Product, grade or purity, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
- We quote. Price, lead time, packing format and a sample COA, normally within one working day.
- Qualify the supply. For first orders or critical applications, we share the analysis and handling documentation so your technical and safety teams can sign off before you commit.
- Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
- Allocation and QC. Material allocated and released against a batch-specific COA, with an independent inspection where the contract calls for it.
- Ship and document. Filled, labelled and loaded with the full export document set, and tracked through to arrival.
Adipic Acid — Common Questions
The questions our technical desk is asked most often about Adipic Acid. If yours isn't here, call or email and you will reach someone who knows the chemistry.
What is the CAS number of adipic acid?
The CAS number for adipic acid is 124-04-9, and its EC number is 204-673-3. Its molecular formula is C₆H₁₀O₄ with a molecular weight of 146.14 g/mol, and it is classified under HS code 2917.12.
What is adipic acid used for?
Mainly for nylon 66, where it reacts with hexamethylenediamine to form nylon salt. Other uses are polyester polyols for polyurethanes, adipate plasticisers, powder coating resins, food acidulation and pharmaceutical excipients.
Do you supply adipic acid worldwide?
Yes. Chelora Chemicals supplies and exports adipic acid worldwide — across Asia Pacific, Europe, the Middle East, Africa and the Americas, as well as throughout India, in bags, jumbo bags and bulk containers.
How is adipic acid manufactured?
By nitric acid oxidation of KA oil, a cyclohexanol and cyclohexanone mixture made from cyclohexane oxidation or phenol hydrogenation. The reaction produces nitrous oxide, which modern plants abate catalytically or thermally.
Why do metals limits matter?
Because iron and other metals catalyse polymer degradation during nylon polymerisation and show up as yellowness in the finished resin or fibre. They have no effect on the acid itself, which is why the specification can look disproportionate.
Is adipic acid safe for food use?
Yes, within approved limits. It is an approved food acidulant in the EU as E355 and in the US and other markets, provided the material is food grade meeting FCC specifications.
Is adipic acid hazardous?
It has low toxicity and is not classified as dangerous goods for transport. It causes serious eye irritation, and its dust is combustible, which is the main workplace hazard requiring ignition control and extraction.
Is adipic acid dust explosive?
Yes, fine adipic acid dust forms explosible clouds with a low enough minimum ignition energy to require earthing, enclosed conveying, extraction and housekeeping as standard practice.
What is the difference between nylon 6 and nylon 66?
Nylon 66 is made from adipic acid and hexamethylenediamine; nylon 6 is made from caprolactam. Nylon 66 melts higher and is stiffer; nylon 6 dyes more easily and absorbs more moisture.
How should adipic acid be stored?
In sealed bags in cool, dry, covered warehousing on pallets, with dust control during handling. Moisture pick-up causes caking and shifts nylon salt stoichiometry.
Why is nitrous oxide an issue in adipic acid production?
Because the nitric acid oxidation step generates N₂O, a greenhouse gas roughly 300 times more potent than CO₂. Abatement is now standard in modern plants and increasingly appears in buyers' supply chain carbon reporting.
What packing sizes and order quantities are available?
25 kg bags, 500 to 1000 kg jumbo bags and bulk containers. Orders run from a pallet of bagged product up to full container and bulk shipments on contract supply.
Ready to source Adipic Acid?
Send us your specification, grade and annual volume. You will get a price, a realistic lead time and a sample COA from someone who understands what the material has to do in your process — delivered anywhere in the world.