Acrylic Acid CAS 79-10-7
Chelora Chemicals supplies glacial and technical grade acrylic acid to superabsorbent polymer, acrylate ester, adhesive and water treatment producers worldwide. Because acrylic acid freezes at 13 °C and polymerises violently when warm, every consignment leaves with a batch-specific COA, the current SDS and full dangerous-goods documentation.
Also known as: AA · Propenoic acid · 2-Propenoic acid · Vinylformic acid · Acroleic acid
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Price, lead time and a sample COA for Acrylic Acid, usually within one working day. We ship worldwide.
Request a Quote Email the DeskDocumentation
- Batch-specific COA (purity, inhibitor, water, dimer)
- Safety Data Sheet (SDS)
- Transport and dangerous-goods documents
- Third-party inspection on request
- Certificate of origin
What is Acrylic Acid?
Acrylic acid is the simplest unsaturated carboxylic acid, C₃H₄O₂, a clear corrosive liquid with a sharp acrid odour. Glacial acrylic acid freezes at 13 °C and is normally held just above that in heated storage.
It is made by two-stage catalytic oxidation of propylene through acrolein, with bio-based routes from glycerol and sugars under development.
Superabsorbent polymers for hygiene products are the largest outlet, followed by acrylate esters for coatings and adhesives, and polyacrylates for water treatment and detergents.
Acrylic acid is corrosive and polymerises exothermically. Uncontrolled polymerisation in a storage tank is one of the more serious runaway scenarios in the chemical industry, and inhibitor plus temperature control are both essential.
Why Acrylic Acid specifically
- A polymerisable acid. Combines a vinyl group with a carboxylic acid, giving polymers that are both reactive and hydrophilic.
- Superabsorbency. Partially neutralised and crosslinked polyacrylate absorbs many times its weight in water.
- Ester versatility. Esterification with alcohols gives the full acrylate ester family for coatings and adhesives.
- Water solubility. Polyacrylates disperse and sequester in water treatment and detergent applications.
How Acrylic Acid is Manufactured
Acrylic acid is made by two-stage oxidation of propylene via acrolein, with glacial grade requiring further purification.
- Propylene feed. Chemical-grade propylene is vaporised and mixed with air and steam.
- First-stage oxidation. Propylene is oxidised to acrolein over a bismuth molybdate catalyst at about 320 °C.
- Second-stage oxidation. Acrolein is oxidised to acrylic acid over a molybdenum-vanadium catalyst at about 250 °C.
- Absorption. The reactor gas is absorbed in water to give crude acrylic acid.
- Extraction and distillation. Solvent extraction and distillation remove water, acetic acid and heavies, producing technical grade.
- Glacial purification. Further distillation and crystallisation give glacial grade for superabsorbent use, with MEHQ dosed throughout.
Typical Commercial Specification
Figures below are representative of glacial acrylic acid. Technical grade for esters carries wider limits — tell us the use and we will send the matching sheet.
| Parameter | Typical Value |
|---|---|
| Appearance | Clear colourless liquid, free of suspended matter |
| Acrylic acid purity | 99.5% min glacial (99.0% technical) |
| Inhibitor (MEHQ) | 180 – 220 ppm, to customer requirement |
| Water | 0.15% max glacial |
| Acetic acid | To grade, typically 0.05% max |
| Propionic acid | To grade, typically 0.05% max |
| Acrylic acid dimer | To grade, typically 0.1% max |
| Aldehydes (as furfural) | To grade, typically 5 ppm max |
| Iron | To grade, typically 0.2 ppm max |
| Colour (APHA) | 10 max |
Physical & Chemical Properties
| Property | Value |
|---|---|
| Chemical formula | C₃H₄O₂ (CH₂=CHCOOH) |
| Molecular weight | 72.06 g/mol |
| Appearance | Clear colourless liquid, sharp acrid odour |
| Boiling point | 141 °C |
| Melting point | 13.5 °C |
| Flash point | About 51 °C (closed cup) |
| Density | 1.051 g/cm³ at 20 °C |
| Vapour pressure | About 0.4 kPa at 20 °C |
| Flammable limits in air | About 2.4 to 8.0% by volume |
| Autoignition temperature | About 438 °C |
| Solubility in water | Completely miscible |
| Heat of polymerisation | About 1070 kJ/kg — a very large exotherm |
| Incompatibilities | Oxidisers, bases, amines, peroxides, iron and rust |
Behaviour in the process
Acrylic acid's freezing point and polymerisation exotherm are the two facts that govern everything:
- Freezes at 13.5 °C. Storage is held just above that, typically 15 to 25 °C. Freezing concentrates inhibitor unevenly, which is dangerous on remelting.
- Violent polymerisation. The heat of polymerisation is about 1070 kJ/kg, among the highest of common monomers; a runaway can destroy a tank.
- Inhibitor needs oxygen. MEHQ requires dissolved oxygen, so air headspace rather than a nitrogen blanket is used.
- Dimerises slowly. Warm storage increases dimer content, which affects superabsorbent polymer performance.
Acrylic Acid Grades and Related Monomers
Acrylic acid is bought by grade, and the glacial grade exists specifically for superabsorbent polymer production.
| Material | Origin / type | When it is the right choice |
|---|---|---|
| Glacial acrylic acid | 99.5%+, low aldehydes and dimer | Superabsorbent polymers and high-performance polyacrylates |
| Technical-grade acrylic acid | 99.0%+ | Acrylate ester production and general polymer use |
| Butyl acrylate | Ester, CAS 141-32-2 | Coatings and adhesives where the ester is used directly |
| 2-Ethylhexyl acrylate | Ester, CAS 103-11-7 | Pressure-sensitive adhesives |
| Methacrylic acid | CAS 79-41-4 | Related monomer giving harder, more weather-resistant polymers |
Stated plainly: glacial grade exists because superabsorbent polymer performance is sensitive to aldehydes and dimer in ways that ester production is not. Paying for glacial grade to make butyl acrylate is money wasted.
Industries We Supply Acrylic Acid To
Acrylic acid reaches hygiene products, coatings, adhesives, water treatment and detergents.
Where Acrylic Acid is Used
Superabsorbent polymers and acrylate esters together take most of global acrylic acid production.
In superabsorbent polymer manufacture
Acrylic acid is partially neutralised with sodium hydroxide, then polymerised with a crosslinker to give a lightly crosslinked sodium polyacrylate network that absorbs many times its weight in fluid. Aldehyde and dimer content in the monomer affect the gel strength and absorption rate, which is why glacial grade carries tighter limits than ester-grade material.
Storage safety
Acrylic acid's polymerisation exotherm is very large, and the classic incident is a tank that was allowed to freeze and was then warmed unevenly. Freezing concentrates inhibitor into some zones and depletes others, so a partly frozen tank can contain inhibitor-free liquid that polymerises on remelting. The rule is simple: never let it freeze, and if it does, treat the whole tank as suspect.
Need a specific grade, purity and packing format?
Tell us the grade, the grade, the inhibitor level and your storage temperature capability, 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 inhibitor, water and dimer reported because all three bear on both safety and polymer performance.
- Acrylic acid purity and water — by gas chromatography and Karl Fischer titration.
- MEHQ inhibitor level — confirming the stability margin for your storage conditions.
- Dimer content — reported because it indicates storage history and affects SAP performance.
- Aldehydes — measured in ppm because they affect superabsorbent gel properties.
- Acetic and propionic acid — reported as the characteristic process impurities.
- Iron and colour — tested because iron catalyses polymerisation and causes colour.
Common Process Problems & Likely Causes
When acrylic acid causes trouble, it is usually temperature, inhibitor, dimer or iron. This table is the shortcut our technical desk works through before anyone opens a complaint file.
| Symptom | Likely cause | What to check |
|---|---|---|
| Tank temperature rising without heating | Polymerisation starting — a serious emergency | Immediate emergency procedure; inhibitor level and tank history |
| Material frozen or slushy on arrival | Storage or transit below 13.5 °C | Transit temperature; treat partly frozen material as inhibitor-uneven |
| Dimer content high | Warm storage or long holding time | Dimer figure and storage temperature history |
| Superabsorbent gel strength low | Aldehydes or dimer in the monomer | Aldehyde and dimer results against the glacial specification |
| Polymerisation initiation slow | Inhibitor level above the recipe allowance | MEHQ figure against your initiator package |
| Corrosion or colour in storage | Iron pick-up from carbon steel equipment | Iron result and material of construction |
Packaging, Storage & Shipping
- Standard packing. 200 L drums, 1000 L IBCs, ISO tank containers and road tankers.
- Temperature control. Hold between 15 and 25 °C. Never allow freezing below 13.5 °C, and never apply localised heat to a frozen tank.
- Oxygen, not nitrogen. MEHQ requires dissolved oxygen; air headspace is standard and a full nitrogen blanket disables the inhibitor.
- Material compatibility. 316 stainless steel. Carbon steel causes iron pick-up, which catalyses polymerisation and discolours the product.
- Circulation. Keep bulk storage circulating so inhibitor stays evenly distributed and no cold spots develop.
- Segregation. Keep strictly apart from bases, amines, oxidisers and peroxides — all initiate polymerisation.
- Shelf life. Typically three to six months at correct temperature. Re-test MEHQ and dimer on stored material.
- Transport classification. UN 2218, acrylic acid stabilised, Class 8 corrosive with subsidiary 3 flammable, packing group II.
Hazards & Safe Handling
Acrylic acid is corrosive, causing severe burns, and polymerises with one of the largest exotherms of any common monomer. Both hazards need active management rather than passive storage.
- Corrosivity. Causes severe skin burns and serious eye damage. Full face and body protection is required for transfer work.
- Polymerisation hazard. Heat of polymerisation around 1070 kJ/kg. A runaway can rupture a storage tank; maintain inhibitor, oxygen and temperature control.
- Freezing hazard. Freezing separates inhibitor unevenly, creating a serious polymerisation risk on remelting.
- Flammability. Flash point about 51 °C; flammable but less volatile than many monomers.
- Respiratory irritation. Vapour strongly irritates eyes, nose and throat; the sharp odour gives warning.
- Occupational exposure. Typical limits are around 2 ppm as an 8-hour average; confirm the limit in your jurisdiction.
- PPE. Acid-resistant gloves, goggles and face shield, chemical suit, and respiratory protection for any breach of containment.
- Environment. Harmful to aquatic life and lowers pH; contain and neutralise spills.
Regulatory & Compliance Notes
Acrylic acid is regulated as a corrosive and flammable liquid with specific polymerisation-hazard provisions. The notes below are orientation rather than legal advice.
- GHS classification. Flammable liquid Category 3, acute toxicity Category 4, skin corrosion Category 1A and acute aquatic toxicity Category 1.
- Dangerous goods transport. UN 2218, acrylic acid stabilised, Class 8 with subsidiary 3, PG II. Stabilisation and temperature control are transport requirements.
- Hygiene product chains. Superabsorbent polymers in personal care are subject to residual monomer and extractable limits.
- REACH and inventories. Registered under EU REACH and listed on the major chemical inventories.
- Process safety. Bulk acrylic acid storage is commonly covered by major-hazard regulations because of the polymerisation runaway potential.
- Quality agreements. SAP producers commonly expect documented inhibitor, dimer and aldehyde limits with change control.
We Supply Acrylic Acid Worldwide
Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Acrylic 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 drums 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 Acrylic Acid from Chelora
We are an independent sourcing and supply partner. For acrylic acid that means settling three things at enquiry: glacial or technical grade, the inhibitor level and temperature control your supply chain can maintain, and the stainless steel handling route into your tankage.
- Documentation on every lot. Batch-specific COA (purity, inhibitor, water, dimer), 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 drums through to full bulk shipments on contract supply.
- Grade matching. Glacial or technical grade with the inhibitor level matched to your storage temperature and polymerisation recipe.
- Inspection. Independent third-party inspection available at loading when the contract requires it.
- Related products. Acrylonitrile, Vinyl Acetate Monomer, Propylene and other feedstocks alongside Acrylic 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.
Acrylic Acid — Common Questions
The questions our technical desk is asked most often about Acrylic Acid. If yours isn't here, call or email and you will reach someone who knows the chemistry.
What is the CAS number of acrylic acid?
The CAS number for acrylic acid is 79-10-7, and its EC number is 201-177-9. Its molecular formula is C₃H₄O₂ with a molecular weight of 72.06 g/mol, and it is classified under HS code 2916.11.
What is acrylic acid used for?
Mainly for superabsorbent polymers in hygiene products and for acrylate esters used in coatings and adhesives. It also goes into water treatment polymers, detergent co-builders, emulsion binders and rheology modifiers.
Do you supply acrylic acid worldwide?
Yes. Chelora Chemicals supplies and exports acrylic acid worldwide — across Asia Pacific, Europe, the Middle East, Africa and the Americas, as well as throughout India. Every consignment carries the COA with inhibitor data, the SDS and the dangerous-goods documentation.
Why must acrylic acid never be allowed to freeze?
Because freezing at 13.5 °C separates the inhibitor unevenly through the frozen mass. Warming one part of a frozen tank can produce inhibitor-free liquid that polymerises violently. A partly frozen tank must be treated as suspect.
How is acrylic acid manufactured?
By two-stage catalytic oxidation of propylene: first to acrolein over a bismuth molybdate catalyst, then to acrylic acid over a molybdenum-vanadium catalyst, followed by absorption, extraction and distillation.
What is the difference between glacial and technical grade?
Glacial grade has tighter limits on aldehydes, dimer and water because superabsorbent polymer performance is sensitive to them. Technical grade is adequate for acrylate ester production and costs less.
Why does acrylic acid need oxygen in the headspace?
Because MEHQ, the inhibitor, requires dissolved oxygen to function. A full nitrogen blanket disables the inhibitor, which is why acrylic acid is stored with air headspace rather than inerted.
Is acrylic acid hazardous?
Yes. It is corrosive, causing severe skin burns and eye damage, and it polymerises with one of the largest exotherms of any common monomer — around 1070 kJ/kg, enough to rupture a storage tank in a runaway.
What are the UN number and transport class?
UN 2218, acrylic acid stabilised, Class 8 corrosive with subsidiary risk 3 flammable, packing group II. Stabilisation and temperature control are transport requirements.
How should acrylic acid be stored?
Between 15 and 25 °C in circulated 316 stainless steel tankage with air headspace, temperature monitoring and alarms, away from bases, amines and oxidisers, and never allowed to freeze.
What is dimer content and why is it reported?
Acrylic acid slowly dimerises, faster when warm. The dimer figure is a direct indicator of storage temperature history and affects superabsorbent polymer gel properties, so it is reported on every lot.
What is the typical shelf life?
Three to six months at correct storage temperature. Re-test MEHQ and dimer content rather than assuming, particularly on material that has been held through a warm season.
Ready to source Acrylic 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.