Polystyrene
Polystyrene's bulky pendant phenyl ring, attached to every other backbone carbon, prevents the chain from packing into a crystalline structure, leaving general-purpose polystyrene (GPPS) glass-clear and rigid but also quite brittle. Blending in a dispersed rubber phase (polybutadiene) — the same toughening principle used in ABS — converts brittle GPPS into high-impact polystyrene (HIPS), trading some clarity and stiffness for the impact resistance general-purpose consumer and appliance parts need.
Chelora Chemicals supplies Polystyrene Resin to packaging, disposable-ware and appliance manufacturers worldwide, in moisture-appropriate bulk packing, with a full batch COA and safety data sheet on every consignment.
Product identity
- CAS Number
- 9003-53-6
- IUPAC name
- Poly(1-phenylethylene)
- Common name
- Poly(styrene) Resin (GPPS/HIPS)
- Molecular formula
- (C8H8)n
- Molecular weight
- Homopolymer — no single molecular weight; commercial resin Mw typically 150,000 – 300,000 depending on grade g/mol
- EC / EINECS
- Polymer — no single EINECS number (CAS-listed polymer)
- SMILES
- *CC(c1ccccc1)*
Note: this is a bulk polymer resin, not a discrete small molecule — the CAS number identifies the polymer class, and the properties that matter commercially (GPPS vs. HIPS, melt flow index, rubber content for HIPS) are set by grade rather than by a single fixed molecular weight; confirm the grade you need when you enquire.
What PS is used for
Because polystyrene's phenyl side-groups are too bulky and irregular to allow ordered chain packing, the polymer is inherently amorphous, which is exactly what gives GPPS its glass-like transparency — a property crystalline polymers cannot offer. HIPS sacrifices some of that clarity by dispersing rubber particles through the matrix (mirroring ABS's SAN-matrix-plus-rubber-phase strategy, but with a plain polystyrene matrix instead of SAN), trading transparency for the impact resistance GPPS alone cannot provide.
Polystyrene's applications split cleanly along the GPPS/HIPS line: GPPS is used for clear packaging (CD/DVD cases, disposable cups and cutlery, laboratory ware) where transparency matters, while HIPS is used for appliance housings, refrigerator door liners, toys and general consumer-goods housings where impact resistance and an excellent surface finish for printing and painting are the priority. Both grades are also foamed for lightweight packaging and, with a pentane blowing agent, as the base resin for expandable polystyrene (EPS) — see our EPS product page.
Related isomers & derivatives
Grade (GPPS vs. HIPS, and melt flow index) is what actually differentiates polystyrene resin lots, more than any structural isomerism:
- General-Purpose Polystyrene (GPPS, unmodified homopolymer, CAS 9003-53-6) — this product's clear grade. Transparent, rigid, but comparatively brittle.
- High-Impact Polystyrene (HIPS, rubber-modified, same base CAS) — dispersed polybutadiene rubber phase gives significantly better impact resistance at the cost of transparency.
- Expandable Polystyrene (EPS, pentane-impregnated beads, same base CAS) — the same polystyrene backbone with an entrained blowing agent, expanded into foam rather than injection or sheet moulded — see our EPS product page.
If your moulding or extrusion process is qualified against a specific GPPS or HIPS grade and melt-flow-index range, confirm that grade on your purchase order — clear and impact grades are not freely interchangeable.
Appearance and handling character
This product ships as solid resin pellets, typically 2–4 mm in size — water-clear and transparent for GPPS grades, or opaque ivory-white (or pre-coloured) for HIPS grades. It is non-hygroscopic and generally does not require pre-drying before processing, though good housekeeping against dust and contamination is still recommended for cosmetic applications.
| Parameter | Typical value |
|---|---|
| Appearance | Transparent, water-clear pellets (GPPS) or opaque, ivory-white pellets (HIPS), typically 2–4 mm |
| Assay (Melt flow index per ASTM D1238) | Resin conforms to grade MFI spec (typically 2 – 20 g/10 min depending on grade) |
| Melting point | No sharp melting point (amorphous); glass transition ≈95 – 100 °C, processing melt range ≈180 – 260 °C |
| Moisture | Reported per batch |
| Colour / impurity profile | Reported per batch |
Important: the figures above are indicative of commercial grade material and are offered for planning only. The batch certificate of analysis is the governing document. If your process demands a tighter specification, send it to us and we will quote against it rather than against a generic grade.
| Property | Value |
|---|---|
| Physical state | Transparent (GPPS) to opaque (HIPS) solid resin pellets |
| Melting point | No sharp melting point (amorphous); glass transition ≈95 – 100 °C, processing melt range ≈180 – 260 °C |
| Boiling point | Decomposes above ≈300 °C rather than boiling |
| Flash point | Not applicable in solid pellet form (combustible solid; see SDS for dust handling) |
| Relative density | ≈ 1.04 – 1.06 g/cm³ (grade-dependent) |
| Water solubility | Insoluble in water; non-hygroscopic |
| Organic solubility | Resistant to dilute acids and alkalis; readily attacked/dissolved by many ketones, esters and aromatic/chlorinated solvents |
Physical constants compiled from public reference data for CAS 9003-53-6 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
The split between transparent GPPS and impact-modified HIPS is what carries polystyrene into both clear packaging and tough consumer-goods housings from the same underlying polymer chemistry.
Clear packaging & disposable ware (GPPS)
GPPS's transparency and rigidity make it the standard resin for CD/DVD cases, disposable cups, cutlery and laboratory ware.
- Confirm your required MFI and clarity specification
- Talk to our technical desk about your specification
Appliance housings & consumer goods (HIPS)
HIPS's impact resistance and excellent surface finish make it the standard resin for appliance housings, refrigerator door liners, toys and general consumer-goods housings.
- See our polymer & resin range
Foam sheet & food packaging
Foamed polystyrene sheet is thermoformed into food trays, egg cartons and protective packaging.
- Ask about food-contact certification for your grade
Electronics & appliance components
HIPS is widely used for internal electronics and appliance components requiring dimensional stability and ease of processing.
- Custom compounding and colour matching available
Expandable polystyrene base resin
The same base polystyrene, impregnated with pentane blowing agent, becomes expandable polystyrene (EPS) — see our EPS product page.
- Confirm your target application (insulation vs. packaging)
Contract & scheduled supply
Packaging and appliance manufacturers running to a production schedule can hold contracted quantity, released against their batch plan.
- Annual contracts with scheduled call-off
- Price held across the contract period
How we supply Polystyrene
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We own no plant of our own — on an intermediate like this one, that independence lets us find the source that can actually deliver your specification and timeline rather than whatever a single captive unit happens to be running.
We place your order with whichever qualified producer best matches your assay, your colour or purity requirement, your price point and your delivery window.
Where a dedicated second source is not readily available, we tell you plainly rather than overstating supply security — and we work with you on lead-time planning accordingly.
- Grade (GPPS/HIPS) and MFI confirmed before quoting. We confirm whether your process is qualified for GPPS or HIPS, and the melt-flow-index range required, before we quote a price.
- Full batch documentation as standard. COA and safety data sheet accompany every consignment.
- Clarity and colour checked for sensitive applications. For GPPS clear-packaging applications, we confirm haze and clarity parameters against the batch COA before shipment.
- Appropriate bulk packing. We pack this resin in bags or bulk containers appropriate to your receiving infrastructure.
- Honest lead-time guidance. We tell you plainly if a particular grade or quantity will take longer than a stocked item, rather than promising a turnaround we cannot deliver.
- Export machinery handled in-house. Documentation, packing, labelling, freight booking and customs paperwork are ours to manage.
Packed the way your lab or plant receives it
Tell us your quantity, physical form and destination and we will quote the packing and Incoterm that fits it.
Multi-wall bags
Multi-wall paper bags with an appropriate inner liner, palletised and shrink-wrapped — the standard format for converter-scale orders.
FIBC / jumbo bags
Bulk bags for larger-volume moulding and extrusion customers, reducing per-kilo handling cost.
Bulk rail/road/sea container
Bulk pneumatic-loaded containers for the highest-volume repeat-contract buyers.
Trial & development samples
Small sealed samples for processing trials and clarity/impact qualification before committing to volume.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to.
Batch-plan despatch
Where your production runs to a batch schedule, we release contracted quantity against your calendar.
Check the batch SDS — it is the governing document
Polystyrene Resin is not classified as hazardous under GHS in its solid pelletised form. It presents a combustible-dust hazard if processed into fine powder, and molten resin presents a thermal-burn hazard during processing, along with irritating fumes (including residual styrene monomer) if overheated. Always read and follow the SDS supplied with your specific batch for processing and dust-handling guidance.
Classified hazards (treat conservatively)
Not classifiedas a hazardous substance under GHS in solid pellet form.Combustible dustnote: fine PS dust generated during regrinding or handling can present a dust-explosion hazard under specific conditions — follow your facility's combustible-dust procedures.Thermal/fume hazardmolten resin during extrusion/moulding presents a burn hazard, and overheating releases irritating fumes including residual styrene monomer; ensure adequate ventilation.
While the resin itself is not classified as hazardous, processors should ensure adequate local exhaust ventilation at injection-moulding and extrusion machines to manage low-level styrene fume emission during normal processing. Always read the SDS issued with your specific batch before finalising your handling procedure.
Spill & emergency orientation
Plan your response before the container arrives, not after a spill occurs. The points below are orientation for your emergency planners — sections 4, 5 and 6 of the SDS are the authoritative instructions and should be posted at the point of use.
- Treat any skin contact, ingestion or inhalation as an emergency — seek medical attention promptly rather than waiting to see whether symptoms develop.
- Contain, do not hose to drain. Sweep or collect the solid, or contain the liquid with absorbent material, into a labelled waste container.
- Avoid breathing dust, fume, gas, mist, vapours or spray during any handling or spill response.
- Wash skin thoroughly after any contact and remove contaminated clothing immediately.
- Have the SDS with the casualty at all times so the treating clinician has the product identity, CAS number and hazard classification in hand.
Storage
- Store in a cool, dry warehouse, off the ground and away from direct sunlight, since UV exposure causes yellowing and embrittlement in unstabilised grades.
- Keep original packaging sealed until use, particularly for GPPS grades sensitive to dust and contamination affecting optical clarity.
- Avoid contact with incompatible chemicals during storage, since many ketones, esters and aromatic/chlorinated solvents readily dissolve or craze polystyrene.
- Follow your facility's combustible-dust procedures, when handling reground flake or fine regrind fractions.
Handling & PPE
- Design exposure out where practical. Closed transfer, local exhaust ventilation and mechanical charging reduce risk regardless of scale.
- Full-coverage, chemical-resistant skin protection as a conservative default — gloves and coveralls, avoiding bare-skin contact.
- Respiratory protection wherever dust, mist or vapour may be present, per your exposure assessment.
- Eye protection and an accessible eyewash and safety shower at every handling point.
- Never discharge to drain or watercourse. The aquatic-toxicity classification applies — dispose of waste as regulated chemical waste.
Transport
We confirm and apply the correct transport classification for every consignment of this compound based on your specific batch's documentation, rather than assuming a fixed classification. We classify each shipment, apply appropriate packaging and labelling, and file the export documentation before booking — ask us for the current paperwork when you plan the shipment.
What travels with every consignment
A chemical shipment is only as good as the file that travels with it. Verifying what the source plant sends is precisely the work you are buying from a supplier.
Certificate of Analysis
Batch-specific assay, appearance, and impurity profile — checked against your purchase specification before we release the goods.
Safety Data Sheet
Full 16-section SDS covering hazards, exposure controls, handling, storage, spill response and disposal, matched precisely to the batch you receive — issued in the language your destination requires.
Transport documentation
Correct classification, packaging and labelling confirmed and filed before the container is booked, whichever transport category the batch falls under.
Certificate of Origin
Chamber-attested where required, plus preferential-origin forms where a trade agreement gives your import duty relief at the destination.
Third-party inspection
SGS, Intertek or Bureau Veritas sampling and inspection arranged on request before loading, giving you independent verification of what actually ships.
Retained & pre-shipment samples
Pre-shipment samples carry the same COA as the commercial lot, so what your laboratory qualifies is exactly what arrives. Retention samples held against the batch.
A bulky-side-group homopolymer, amorphous by structure, toughened by design
Polystyrene is manufactured by free-radical bulk, solution or suspension polymerisation of styrene monomer, with polybutadiene rubber grafted in during polymerisation for HIPS grades. The notes below are general background, not process instructions.
Start from styrene monomer
Styrene, itself derived from ethylbenzene (from ethylene and benzene), is the sole monomer for GPPS.
Free-radical bulk or solution polymerisation
Thermal or peroxide-initiated free-radical polymerisation builds the polystyrene chain; for HIPS, polybutadiene rubber is dissolved in the styrene feed and grafted during polymerisation.
Devolatilise and pelletise
Residual monomer is stripped under vacuum and the polymer is pelletised, with colourants or additives compounded in as specified.
Test and certify MFI and mechanical properties
Melt flow index and, for HIPS, impact strength testing certify the material against the target grade before release.
Why isomer and substitution pattern matter
Because GPPS/HIPS selection and MFI are the parameters your moulding or extrusion process is actually qualified against, substituting a different polystyrene grade — or a different resin family entirely — changes processing behaviour and part performance directly:
- GPPS used where HIPS's impact resistance was required will be significantly more brittle and prone to cracking in drop or impact scenarios.
- HIPS used where GPPS's transparency was required will not deliver the optical clarity clear-packaging applications need.
- ABS substituted for HIPS offers better impact resistance and heat resistance at a higher cost, and is not a drop-in substitute without reprocessing validation.
- Recycled or regrind content above your process tolerance can reduce impact strength and surface gloss — confirm virgin/regrind ratio requirements before ordering.
That chain of consequences is the reason we quote against your written specification rather than a generic grade, and the reason the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Intermediate | Principal outlet |
|---|---|
| Polystyrene CAS 9003-53-6 — this product | Clear packaging (GPPS) & appliance housings (HIPS) Styrenic homopolymer |
| Expandable Polystyrene (EPS) CAS 9003-53-6 | Foam insulation & packaging See our product page |
If your route calls for one of the others, we supply those as well — see the full intermediate range. Send the CAS number and we will confirm the correct material before quoting.
What actually moves the price of this intermediate
Knowing what drives the quote helps you plan a purchase realistically.
Producer base & capacity
A large number of petrochemical manufacturers produce polystyrene at commercial scale worldwide; pricing tracks styrene feedstock cost and, for HIPS, butadiene rubber cost, closely.
- Qualify a source well ahead of when you need volume
- Custom production runs may carry longer lead times
- We are transparent about single-source risk here
Upstream feedstock
The route runs through styrene, itself derived from ethylbenzene (ethylene and benzene). Styrene market pricing feeds through relatively quickly, given its actively traded commodity market.
- Feedstock cost sets the floor on price
- We flag feedstock-driven moves in the quote
Purity and grade tier
Higher-purity, tightly specified material prices above a general technical grade. Tell us your actual end use and we will avoid over-specifying.
- Tell us the reaction you are running
- We will say when a tighter spec is unnecessary
Order size and pack format
Most buyers order in commercial pack sizes rather than bulk tonnage. If your requirement genuinely is bulk, tell us early — the sourcing conversation is quite different from a small commercial order.
- Small commercial packs are readily available
- Bulk orders need advance lead-time planning
Freight considerations
Confirm the correct transport classification for your specific batch — this affects freight cost and available carrier options, and we handle that confirmation as part of every quote.
- Classification confirmed per batch
- We quote FOB, CIF, CFR or DDP as you prefer
Lead time realism
We would rather tell you honestly that a custom lot will take several weeks than promise a stocked-item turnaround we cannot deliver.
- Ask early for the most accurate lead time
- Sample qualification adds time but reduces risk
| If your end use is… | Specify |
|---|---|
| Clear packaging / disposable ware | GPPS, confirm MFI and clarity |
| Appliance housings / consumer goods | HIPS, confirm impact-strength requirement |
| Foam sheet / food packaging | Confirm foam density and food-contact certification |
| EPS base resin | See our EPS product page |
Not sure which row you are in? Describe the reaction you are running and our technical desk will confirm the exact grade you need.
Support that goes beyond shipping the pack
What our technical desk will do
- Confirm the exact isomer and substitution pattern. With closely related nitroaromatic isomers in this family, we check the CAS number before we quote, every time.
- Verify the hazard classification against your specific batch. We do not rely on a single reference source — we check the SDS for the lot we are quoting.
- Give you honest lead-time guidance for a product that may not always be stocked.
- Review your specification before it goes into a contract, so you are not locked into a limit that no plant can consistently hit.
Regulatory & compliance notes
- Import controls vary by destination. We check the destination rules before quoting, not after you have raised the PO.
- Chemical inventory listings differ between regions. Confirm your obligations under the applicable inventory regime for your import volume — we will supply the identity data you need for that filing.
- Transport classification is confirmed for every batch based on its own documentation and filed before booking.
- Downstream regulatory status of whatever you build from this intermediate is a separate question your own regulatory team should confirm for your specific finished product.
None of the above is legal advice — your own regulatory affairs team owns the final compliance position for your import. What we commit to is giving you accurate product identity data, an honest statement of the hazard classification for your specific batch, and complete documentation to work from.
From enquiry to delivered pack
Send the specification
Product name or CAS 9003-53-6, the assay and purity limits you work to, quantity, pack preference and destination port.
Receive a firm quote
Pricing, realistic lead time, packing and Incoterm confirmed in writing within 24 hours — our sourcing desk is staffed around the clock.
Qualify and approve
Sample dispatched if you are qualifying a new source. Batch COA and matching SDS shared for your approval before the material is released.
Ship and track
Correct classification confirmed, freight booked, export documents issued, and the consignment tracked through transit and clearance to your plant.
Other nitroaromatic intermediates we supply
What buyers ask us about Polystyrene
What is Polystyrene mainly used for?
What is the difference between GPPS and HIPS?
Is Expandable Polystyrene (EPS) a different material?
What safety precautions apply to this product?
What is the minimum order quantity?
How long does delivery take?
What paperwork comes with the consignment?
- Batch certificate of analysis (MFI, mechanical/optical properties)
- Safety data sheet
- Food-contact certification where applicable
- Commercial invoice, packing list and bill of lading
- Certificate of origin and any destination-specific forms
Do you manufacture this yourself?
Request pricing on Polystyrene
Send your required assay, quantity, pack format and destination port. Our sourcing desk is available 24 hours a day, 7 days a week, and comes back with pricing, an honest lead time, and packing options for whatever volume you need.