1,3-Butadiene
The essential conjugated diene. A colourless, flammable gas with two conjugated C=C double bonds — the irreplaceable feedstock for SBR, PBR, nitrile rubber, ABS, and nylon-6,6 intermediates.
Molecular Structure
What is 1,3-Butadiene?
1,3-Butadiene is a four-carbon diene with two conjugated C=C double bonds. It is produced mainly as a C₄ by-product of steam cracking and is the foundation of the synthetic rubber industry.
The conjugated diene system gives 1,3-butadiene unique reactivity: 1,2- and 1,4-addition, Diels–Alder cycloaddition, and free-radical or anionic polymerisation to give elastomers with outstanding resilience and abrasion resistance. The 1,4-microstructure of polybutadiene and SBR determines the glass transition temperature and tyre performance.
Chelora sources polymer-grade 1,3-butadiene (≥99.3%) from cracker C₄ fractions with strict control of inhibitor (TBC) levels, vinylacetylene, and moisture. Full documentation and logistics support provided.
Quick Reference
Key Physical & Chemical Properties
Structure & Bonding
1,3-Butadiene's reactivity is defined by its Conjugated C=C–C=C — the site of polymerisation and other industrially important reactions.
Lewis structure — sp² (all 4 C)
Structural Identity
- IUPAC NameButa-1,3-diene
- Molecular FormulaC₄H₆
- Molecular Weight54.09 g/mol
- Hybridisationsp² (all 4 C)
- Bond typeConjugated C=C–C=C
- C=C bond length1.34 Å (C=C) / 1.47 Å (C–C)
- GeometryPlanar (s-trans conformation)
- CAS Number106-99-0
- InChI KeyKAKZBPTYRLMSJV-UHFFFAOYSA-N
Product Specifications
Chelora supplies 1,3-Butadiene in standard and custom grades. Contact us for specification sheets tailored to your process.
| Chemical name | 1,3-Butadiene |
|---|---|
| CAS Number | 106-99-0 |
| Molecular formula | C₄H₆ |
| Molecular weight | 54.09 g/mol |
| Purity (standard grade) | ≥ 99.3 mol% |
| Purity (commercial grade) | ≥ 98.5 mol% |
| Physical state (ambient) | Gas (ambient) |
| Boiling point | −4.4 °C at 1 atm |
| Melting point | −108.9 °C |
| Flammable limits | 2.0 – 11.5% v/v v/v in air |
| Vinylacetylene (max, PG) | ≤ 10 ppm vol |
| 1,2-Butadiene (max) | ≤ 100 ppm vol |
| TBC inhibitor | 50–200 ppm wt |
| Moisture (max) | ≤ 30 ppm wt |
| Critical temperature | 152 °C |
| Critical pressure | 43.3 bar |
| UN Number | UN 1010 |
| IMO / IMDG Class | Class 2.1 (Flammable Gas) |
Downstream Applications & Derivatives
Key derivative chains and industrial uses of 1,3-Butadiene.
Styrene-Butadiene Rubber (SBR)
The world's largest-volume synthetic rubber. SBR (copolymer of butadiene and styrene) is used in passenger and truck tyres, conveyor belts, footwear, and hose.
Polybutadiene Rubber (PBR/BR)
High-cis polybutadiene produced with Nd or Co/Ni/Ti catalysts — valued for low rolling resistance and high resilience in tyre sidewalls and golf ball cores.
Nitrile Rubber (NBR)
Copolymerisation of butadiene with acrylonitrile gives NBR — the standard elastomer for oil-resistant seals, O-rings, hoses, and fuel system components.
ABS & SAN Resins
Butadiene rubber latex is grafted with styrene–acrylonitrile to give ABS — the dominant engineering thermoplastic for automotive, consumer electronics, and appliance housings.
Nylon-6,6 Intermediates
Hydrocyanation of butadiene with HCN gives adiponitrile (ADN), which is hydrogenated to hexamethylenediamine (HMDA) — one of the two monomers for nylon-6,6.
SBS & SIS Block Copolymers
Anionic polymerisation with lithium initiators gives SBS and SEBS thermoplastic elastomers used in adhesives, bitumen modification, and soft-touch applications.
Why source 1,3-Butadiene through Chelora Petrochem?
Verified Origin
Full origin certification and asset-backed supply chain documentation — no grey-market supply.
Grade Flexibility
Standard and custom grades available. Impurity specifications can be tailored to your process and catalyst system.
Full Documentation
CoA, SDS, UN transport docs, REACH compliance, and destination-market certificates with every shipment.
Logistics Support
Experienced in specialised chemical logistics for compressed gases and volatile liquids — Indian and international delivery.
Storage & Handling Guidelines
Always refer to the full SDS before handling. The following is a summary of key requirements.
- Store in a well-ventilated, dedicated area away from ignition sources, heat, and sunlight.
- All electrical equipment in storage and handling areas must be ATEX/IECEx rated for the applicable zone.
- Ensure full bonding and earthing of all transfer equipment during any transfer operation.
- Never store with strong oxidisers, halogens, or materials that generate static.
- Install continuous gas detection with audible and visual alarms set below the LEL.
- Use only approved pressure-rated piping, valves, and fittings with compatible materials.
- Conduct pre-use and post-use leak checks with suitable gas detection equipment.
- Maintain inhibitor levels where applicable; check on receipt and periodically during storage.
Hazard Summary
Classification: Flammable Gas/Liquid · Flammable limits 2.0 – 11.5% v/v v/v · UN 1010.
Flammability: Highly flammable — never rely on odour to detect leaks. Use continuous gas monitoring below LEL.
Health: Asphyxiant in enclosed spaces. Oxygen monitoring mandatory in confined areas. Follow occupational exposure limits (OELs) per SDS.
PPE minimum: Chemical goggles, appropriate gloves, flame-retardant clothing, and supplied-air respirator where oxygen deficiency is possible.
Consult the full SDS for exposure limits, spill containment, emergency response, and disposal before any use.
Frequently Asked Questions
Technical and commercial questions about 1,3-Butadiene sourcing and specifications.
What is 1,3-butadiene used for?
1,3-Butadiene is the primary feedstock for the synthetic rubber industry — SBR (tyres), polybutadiene rubber, nitrile rubber (NBR), and neoprene — and for ABS engineering resin, nylon-6,6 intermediates (via adiponitrile), and SBS/SEBS thermoplastic elastomers.
Why does 1,3-butadiene require an inhibitor during storage?
Butadiene can undergo spontaneous, exothermic polymerisation (popcorn polymerisation) especially in the presence of oxygen or at elevated temperature. TBC (tert-butylcatechol) inhibitor is added at 50–200 ppm to prevent runaway. Inhibitor level must be verified before and during storage — material with degraded inhibitor must not be used.
How is 1,3-butadiene produced?
The dominant route is extraction from the C₄ fraction of steam crackers using extractive distillation (NMP or DMF solvent process). Minor routes include dehydrogenation of n-butane or n-butenes (Houdry, oxidative dehydrogenation). Cracker co-production means butadiene supply is partly linked to ethylene/naphtha cracker operating rates.
Is 1,3-butadiene carcinogenic?
Yes — 1,3-butadiene is classified as a Group 1 human carcinogen (IARC) and a known carcinogen under many national regulations. Handling must comply strictly with applicable occupational exposure limits (OELs), which are typically very low (e.g. 1–2 ppm TWA). Closed-system handling, continuous gas detection, and full PPE are mandatory.
What is the CAS number for 1,3-butadiene?
1,3-Butadiene has CAS number 106-99-0, molecular formula C₄H₆, and molecular weight 54.09 g/mol. Its IUPAC name is buta-1,3-diene. The four carbon atoms are all sp²-hybridised, giving a conjugated π system with a planar s-trans ground-state conformation.
What documentation does Chelora provide?
Every shipment includes a Certificate of Analysis (CoA) covering purity, vinylacetylene, 1,2-butadiene, inhibitor level and moisture; a Safety Data Sheet (SDS) per GHS/REACH; UN transport documents; and any destination-market regulatory certificates.
Request a quote or specification sheet
Talk to Chelora's sourcing team about 1,3-Butadiene grade, volume, logistics, documentation, and lead times. We respond within one business day.
