Isoprene
The monomer behind synthetic natural rubber — polymerised into cis-1,4-polyisoprene, and copolymerised into butyl rubber and SIS block copolymers.
Chelora Chemicals supplies inhibitor-stabilised isoprene to rubber and adhesive producers worldwide, with full documentation on every consignment.
Product identity
- CAS Number
- 78-79-5
- IUPAC name
- 2-Methylbuta-1,3-diene
- Molecular formula
- C₅H₈
- Molecular weight
- 68.12 g/mol
- Boiling point
- 34.0 °C
- Melting point
- -146 °C
- UN Number
- UN 1218
- HS Code
- 2901 24
Note: Isoprene is shipped stabilised with a polymerisation inhibitor; its low boiling point means it is handled as a cool, volatile liquid. Confirm requirements with your regulatory affairs team.
What Isoprene is used for
Isoprene is a colourless, highly volatile, flammable liquid with a mild, pungent odour, boiling just above room temperature. It is the five-carbon conjugated diene that forms the structural repeat unit of natural rubber, and is produced industrially mainly as a C5 co-product of ethylene steam cracking, extracted from pyrolysis gasoline.
Isoprene's single largest use is as the monomer for synthetic cis-1,4-polyisoprene rubber, a close structural match to natural rubber used in tyres, footwear and mechanical rubber goods. It is also copolymerised in small fractions with isobutylene into butyl rubber, and with styrene into styrene-isoprene-styrene (SIS) block copolymers used in pressure-sensitive adhesives and sealants.
Where it sits in the petrochemical value chain
- Ethylene steam cracking the source of the C5 pyrolysis-gasoline stream that isoprene is extracted from.
- Isoprene (this product) the diene monomer for the rubber and copolymer chains below.
- Polyisoprene / Butyl Rubber / SIS downstream rubber and block-copolymer chains built on this monomer. See Isobutylene.
Handling character
Isoprene is extremely flammable, volatile, and a suspected human carcinogen, requiring inhibitor stabilisation and careful temperature control. Full hazard detail is in the Safety section below.
| Parameter | Typical value |
|---|---|
| Appearance | Colourless, volatile liquid |
| Assay | 99.0% min (polymer grade) |
| Dimer/peroxide content | Within producer specification |
| Inhibitor (TBC) content | Within producer specification |
Important: the figures above are indicative of commercial material and are offered for planning only. The batch certificate of analysis is the governing document.
| Property | Value |
|---|---|
| Physical state | Colourless, highly volatile, flammable liquid |
| Boiling point | 34.0 °C |
| Melting point | -146 °C |
| Density | 0.681 g/cm³ |
| Water solubility | Slightly soluble (~641 mg/L) |
| Flash point | -54 °C (extremely flammable) |
Physical constants compiled from public reference data for CAS 78-79-5 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put Isoprene to work
The diene behind synthetic natural rubber, butyl rubber and performance adhesives.
Synthetic polyisoprene rubber
Polymerised into cis-1,4-polyisoprene, a close match to natural rubber for tyres and mechanical goods.
- Polymer-grade specification
- Inhibited bulk & drum supply
- Technical desk review on request
Butyl rubber comonomer
Copolymerised in small fractions with isobutylene into butyl rubber for innertubes and seals.
- Industrial-grade specification
- Documented batch traceability
- Contract & spot supply
SIS block copolymers
Copolymerised with styrene into SIS thermoplastic elastomers for adhesives and sealants.
- Full analytical documentation available
- Retained sample held against the lot
Footwear & latex
Polyisoprene latex used in footwear soles, gloves and dipped-rubber goods.
- Documented batch traceability
- Technical desk review on request
Fine-chemical synthesis
Feedstock for terpenoid and fragrance-chemical synthesis in smaller volumes.
- Research & process-scale quantities
- Full documentation supplied
Contract & scheduled supply
Rubber and adhesive plants running continuous consumption are supported with scheduled bulk delivery.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply Isoprene
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. Isoprene's volatility and peroxide-formation tendency make inhibitor level and cold-chain logistics critical — that shapes how we manage this line.
We place your order with whichever qualified producer best matches your required grade, your price point and your delivery window, and confirm your jurisdiction's import requirements before booking.
We keep a second qualified source on this line, so a single-plant disruption never becomes your production problem.
- Inhibitor and dimer/peroxide levels confirmed before we quote. Consistency matters to downstream polyisoprene and butyl-rubber polymerisation.
- UN 1218 documentation managed end to end. Classification, labelling and carrier compliance confirmed before booking.
- Temperature-controlled logistics arranged where needed. Isoprene's low boiling point means cool-chain handling matters for quality retention.
- Batch traceability to the producing plant. Full chain of custody documentation on request.
- Export machinery handled in-house. Classification, approved packing, labelling, freight booking and customs paperwork are ours to manage.
- Polymer-grade material sourced to your process. Matched precisely to your rubber or block-copolymer specification.
Packed the way your plant receives it
Drum, tote or bulk tank — tell us your preferred format and we will quote and classify to it.
200-180 litre drums
Steel drums, inhibitor-stabilised, for smaller-volume orders and trial quantities.
~1,000 litre totes
Returnable or one-way IBC totes sized for mid-volume converter orders.
Large-volume bulk shipment
Pressurised or refrigerated ISO tank bulk shipment for continuous-consumption rubber plants.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with documentation filed before booking.
Trial / sample quantities
Small packs dispatched for process trials before a commercial order is placed.
Contracted call-off supply
We hold contracted tonnage and release it against your consumption calendar.
Extremely flammable & volatile — handle accordingly
Isoprene is extremely flammable, highly volatile, and a suspected human carcinogen, and can form explosive peroxides without adequate inhibitor. The summary below is orientation only — the safety data sheet supplied with your specific batch is the authoritative document.
Classified hazards
H224Extremely flammable liquid and vapour.H351Suspected of causing cancer.H315+H319Causes skin and eye irritation.
Maintain inhibitor levels at all times. Inadequately inhibited isoprene can form explosive peroxides in storage; always read the SDS issued with your specific batch and follow site exposure-control procedures.
Storage
Store inhibited material in tightly closed, cooled containers away from heat, sunlight, oxidising agents and oxygen ingress, with adequate ventilation given its low boiling point.
Handling
Use chemical-resistant gloves, eye protection and respiratory protection where vapour control is needed. Avoid inhalation and skin contact; provide forced ventilation and eliminate ignition sources when handling.
Transport
Shipped as UN 1218 (Isoprene, stabilized), an extremely flammable liquid. We confirm and document exact classification for your specific shipment and destination.
Every batch, documented
We verify documentation before dispatch so there are no surprises at your incoming-goods bench.
Specification agreed
Assay, dimer/peroxide content and inhibitor level confirmed against your polymerisation route before order placement.
Producer batch testing
The producing plant tests each batch against the agreed specification before release.
Documentation review
COA, SDS and transport paperwork checked by our desk before the shipment is booked.
Traceable dispatch
Each shipment is traceable to its producing batch, with full chain-of-custody records on request.
How Isoprene is made
Isoprene is recovered industrially mainly as a C5 co-product of ethylene steam cracking, extracted from the pyrolysis gasoline fraction by extractive distillation, in a manner analogous to butadiene recovery from the C4 stream. On-purpose routes, including dehydrogenation of isopentane/isoamylenes, supplement supply where cracker-derived volumes are insufficient.
We do not publish operating process parameters here; this is background only. Full technical documentation accompanies every shipment, and any process-specific detail you need is best confirmed directly with our technical desk.
| Chemical family | Conjugated diene (branched C5) |
|---|---|
| Functional groups | Two conjugated carbon-carbon double bonds |
| Reactivity | Stereospecific (co)polymerisation; Diels-Alder diene; forms peroxides with oxygen |
| Related compounds | 1,3-Butadiene, Isobutylene (related C4/C5 dienes/olefins), Polyisoprene, Butyl Rubber (downstream) |
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Isoprene, answered
What is Isoprene used for?
How is Isoprene made?
Is Isoprene hazardous?
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What packing do you offer?
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