Styrene Monomer
The vinyl aromatic monomer supplied by Chelora Chemicals — the building block for polystyrene, ABS, SAN resins and styrene-butadiene rubber, one of the highest-volume monomers in the plastics industry — exported from Indonesia in inhibited, stabilised ISO tanks and drums with full batch documentation on every shipment.
What Styrene Monomer is, and why buyers source it
A working overview of the compound's chemistry, its role as a reactive vinyl monomer, and the grades Chelora Chemicals keeps in regular supply.
Styrene Monomer is a benzene ring carrying a vinyl (ethenyl) substituent — a reactive carbon-carbon double bond conjugated with the aromatic ring. That conjugation both stabilises the double bond enough for the monomer to be stored and handled, and activates it enough to polymerise readily once a radical initiator, heat or light provides the trigger, which is exactly the balance that makes styrene the workhorse vinyl monomer of the plastics industry.
At room temperature it is a colourless to pale-yellow liquid with a characteristic sweet, pungent odour, immiscible with water but miscible with most organic solvents. Because it polymerises spontaneously on standing, especially when warm or exposed to light, every commercial batch is stabilised with a polymerisation inhibitor (commonly tert-butylcatechol) and requires minimum headspace oxygen to remain effective.
Where it fits in the synthesis chain
Styrene Monomer is the building block for polystyrene (general-purpose and high-impact grades), ABS and SAN engineering resins, styrene-butadiene rubber (SBR) and latex, and, as a reactive diluent and crosslinker, unsaturated polyester resins used in fibreglass composites, gelcoats and marine construction. Its combination of low cost, easy polymerisation and useful end-product properties makes it one of the highest-volume monomers produced worldwide.
Grades we supply
Chelora Chemicals offers Styrene Monomer in standard polymer grade (99.6%+ assay, inhibited with 10–15 ppm TBC) for general polystyrene, ABS/SAN and SBR manufacture, and premium polymer grade (99.8%+, lower aldehyde and polymer content) for specialty and optical-grade resin applications. Both grades are supplied with a batch-wise certificate of analysis.
How Styrene Monomer is made
An overview of the production route for orientation purposes. Our manufacturing partners' own process parameters and in-process controls are proprietary and are not disclosed beyond what is needed to interpret the certificate of analysis.
Styrene Monomer is manufactured almost entirely by the catalytic dehydrogenation of ethylbenzene: C₆H₅C₂H₅ → C₆H₅CH=CH₂ + H₂, run at high temperature over an iron-oxide-based catalyst in the presence of a large excess of superheated steam, which supplies heat, dilutes the reaction to favour the forward (equilibrium-limited) reaction, and helps keep the catalyst free of coke. A smaller share of world capacity uses the alternative co-product route, in which ethylbenzene hydroperoxide epoxidises propylene to propylene oxide while being reduced to a styrene precursor (the POSM/SMPO process).
Why steam dehydrogenation is the standard route
Direct dehydrogenation of ethylbenzene gives styrene in a single step from a feedstock that is itself made at large scale specifically for this purpose, and the steam-dilution approach manages both the reaction equilibrium and catalyst fouling in a well-understood, widely licensed process that dominates global styrene capacity.
Industries and processes that use it
Styrene Monomer is consumed across the full range of styrenic plastics, elastomers and composite resins, where its combination of low cost and reactive vinyl chemistry is the main draw. The fields below account for most of the demand we see through our export desk.
Polystyrene (GPPS/HIPS)
Polymerised alone, or with a small amount of rubber modifier, to make general-purpose and high-impact polystyrene used in packaging, appliances and disposables.
ABS & SAN Engineering Resins
Copolymerised with acrylonitrile and butadiene to make ABS, and with acrylonitrile alone to make SAN, both widely used engineering thermoplastics.
Styrene-Butadiene Rubber (SBR) & Latex
Copolymerised with butadiene to make SBR, a major synthetic rubber used in tyres, and styrene-butadiene latex used in paper coating and adhesives.
Unsaturated Polyester Resin Crosslinker
Used as a reactive diluent and crosslinking monomer in unsaturated polyester resins for fibreglass composites, gelcoats and marine construction.
How the molecule is typically carried forward
The conjugated vinyl group governs almost all of this molecule's further reaction chemistry. Reaction classes below account for most of the ways Styrene Monomer is converted into a finished product or intermediate.
Free-Radical Homopolymerisation
A radical initiator opens the vinyl double bond and propagates a growing polymer chain, the basic reaction behind polystyrene manufacture.
Free-Radical Copolymerisation
Styrene copolymerises readily with acrylonitrile, butadiene and other vinyl monomers to build ABS, SAN and SBR, tuning impact strength, clarity and chemical resistance.
Crosslinking Copolymerisation (Polyester Resins)
Styrene reacts with the unsaturation sites along an unsaturated polyester prepolymer chain, crosslinking it into a rigid thermoset network.
Catalytic Dehydrogenation (Upstream)
Ethylbenzene loses hydrogen over an iron-oxide catalyst to form styrene monomer itself, the first and essentially only step in the whole chain.
Styrene Monomer against other amines we supply
Buyers sourcing Styrene Monomer for plastics, rubber or composite-resin manufacture often need the upstream feedstock or a related aromatic. A quick reference to what else is on our regular supply list.
| Product | CAS Number | Category | Notes |
|---|---|---|---|
| Styrene Monomer | 100-42-5 | Vinyl aromatic monomer | The product on this page — the building block for polystyrene, ABS, SAN and SBR. |
| Ethylbenzene | 100-41-4 | Alkylbenzene (C8) | The direct upstream feedstock, dehydrogenated to styrene — see its product page. |
| Cumene | 98-82-8 | Alkylbenzene (C9) | A related alkylbenzene made by an analogous Friedel-Crafts route — see its product page. |
| Mixed Xylenes | 1330-20-7 | C8 aromatic isomer blend | A related C8 aromatic stream — see its product page. |
Exact physical constants and purity specifications are confirmed per batch on the certificate of analysis — treat the notes above as a sourcing guide, not a specification sheet, for products other than Styrene Monomer.
Safety classification at a glance
Based on GHS classification as commonly listed for this substance. This is a summary for orientation only — always work from the current safety data sheet supplied with your specific batch.
Flammable liquid and vapour.
Causes skin irritation.
Causes serious eye irritation.
Harmful if inhaled.
Chemical-resistant gloves, splash goggles and suitable respiratory protection are the baseline for routine handling.
Keep away from heat, sparks and open flame; ground and bond containers during transfer.
Can polymerise violently and exothermically if the inhibitor is depleted or exposed to excess heat, oxygen deficiency or contamination — monitor inhibitor level in long-term storage.
Danger — GHS02 flammable and GHS07 harmful pictograms apply.
This compound is a flammable liquid that causes skin and serious eye irritation, and is harmful if inhaled. It can also polymerise violently if its inhibitor is depleted or it is exposed to excess heat, so inhibitor level and storage temperature must be monitored throughout shipping and storage. It must be handled with chemical-resistant gloves, splash-proof eye protection and suitable respiratory protection. Full first-aid, storage, spill and PPE guidance is in the MSDS issued with every shipment, and should be read in full before this material is handled.
Keeping it on spec between delivery and use
General storage guidance for this grade. Site-specific storage rules, segregation requirements and re-test intervals should follow your own EHS procedures and the MSDS issued with your batch.
Store in a cool area below 20 °C, out of direct sunlight and away from heat sources, peroxides and any polymerisation initiators, in tightly closed original packaging with the specified minimum oxygen headspace to keep the inhibitor effective. Monitor temperature during storage and transport, since elevated temperature accelerates inhibitor depletion and raises the risk of runaway polymerisation. If a batch is held past its retest date, re-check inhibitor level, polymer content and colour before use.
How it ships from Indonesia
Standard packing and export terms for this product. Confirm exact figures against your order — they vary slightly by destination and quantity.
What travels with every batch
Specification is agreed before the purchase order, not discovered on arrival. Every shipment of Styrene Monomer leaves with a documented, checkable paper trail.
Certificate of Analysis
Batch-wise assay (by titration/GC), colour and relevant physical constants, issued against the agreed specification so your QC team can check it, not just file it.
Safety Data Sheet
GHS-format SDS in English covering hazard classification, handling, storage, first-aid and spill response for the exact grade of Styrene Monomer shipped.
Technical Data Sheet
Reference physical and chemical properties, recommended storage and typical applications, for internal circulation to your process or R&D teams.
Certificate of Origin
Confirms Indonesian origin for customs clearance and any preferential-duty claim at your destination port.
Dangerous Goods Declaration
UN packing group, classification and shipper's declaration prepared ahead of loading so documentation never holds up customs.
Third-Party Inspection
Independent pre-shipment inspection and re-sampling can be arranged on request, at your cost, for buyers who require it as a matter of policy.
Frequently asked questions
What buyers most often ask our sales desk about this grade.
01What is Styrene Monomer used for?+
02What is the CAS number of Styrene Monomer?+
03How is Styrene Monomer made?+
04What purity grades does Chelora Chemicals supply?+
05Is Styrene Monomer hazardous?+
06Why does Styrene Monomer need an inhibitor during storage?+
07What packing options are available?+
08How long does delivery take?+
09Can I get a sample before placing a bulk order?+
10Do you supply the upstream feedstock, ethylbenzene, as well?+
Need Styrene Monomer on spec, on time?
Send us your required purity, quantity, packing preference and destination port. Our desk quotes most enquiries within one working day.