Purified Terephthalic Acid
The primary acid-side monomer for PET and polyester — polycondensed with Mono Ethylene Glycol to supply the global bottle-resin, textile-fibre and film industries.
Chelora Chemicals supplies PTA to PET and polyester manufacturers worldwide, with full documentation and consistent purity on every consignment.
Product identity
- CAS Number
- 100-21-0
- IUPAC name
- Benzene-1,4-dicarboxylic acid
- Molecular formula
- C₈H₆O₄
- Molecular weight
- 166.13 g/mol
- Melting point
- ~300 °C (sublimes)
- Density
- 1.519 g/cm³
- GHS Pictogram
- GHS07
- HS Code
- 2917 36
Note: PTA decomposes/sublimes rather than exhibiting a conventional boiling point. We confirm transport classification for your specific shipment before booking.
What Purified Terephthalic Acid is used for
Purified Terephthalic Acid (PTA) is a white crystalline powder, an aromatic dicarboxylic acid that decomposes/sublimes rather than melting or boiling conventionally, and is only sparingly soluble in water at room temperature.
PTA's defining use is as the primary acid-side monomer for PET resin and polyester fibre: it reacts with Mono Ethylene Glycol (MEG) in a direct-esterification reaction to form polyethylene terephthalate. This has become the dominant commercial route to PET worldwide, used across bottle-grade resin, textile and carpet fibre, packaging film, and engineering-grade PET — largely displacing the older transesterification route that used Dimethyl Terephthalate (DMT) in place of PTA.
Where it sits in the polyester value chain
- Purified Terephthalic Acid (this product) the acid-side monomer, direct-esterified with MEG.
- Mono Ethylene Glycol the diol-side monomer it reacts with. See that page.
- PET Resin the polymer formed from the two. See that page.
Handling character
PTA carries a GHS Warning signal word, causing skin and eye irritation and harmful if inhaled. Full hazard detail is in the Safety section below.
| Parameter | Typical value |
|---|---|
| Appearance | White crystalline powder |
| Assay | 99.9% min (fibre/bottle grade) |
| 4-CBA content | Within producer specification |
| Colour (b-value) | 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 | White crystalline powder |
| Thermal behaviour | Decomposes/sublimes ~300 °C |
| Density | 1.519 g/cm³ |
| Water solubility | Sparingly soluble at room temperature |
Physical constants compiled from public reference data for CAS 100-21-0 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this monomer to work
The acid-side half of the world's most widely produced polyester polymer.
PET bottle resin
Direct-esterified with MEG to produce bottle-grade PET for packaging and beverage containers.
- Bottle-grade specification
- Bulk & bag supply
- Technical desk review on request
Polyester textile & carpet fibre
Forms the acid-side monomer input for polyester fibre spun into textiles and carpets.
- Fibre-grade specification
- Documented batch traceability
Packaging & industrial film
Underpins PET film used in packaging, lamination and industrial applications.
- Contract & spot supply
- Full analytical documentation available
Engineering-grade PET & PBT
Used in engineering-resin grades of PET and in PBT (polybutylene terephthalate) production.
- Packs sized to customer volumes
- Retained sample held against the lot
Unsaturated polyester resins
Contributes to UPR formulations for coatings, laminates and composites.
- Research & process-scale quantities
- Full documentation supplied
Contract & scheduled supply
PET and polyester plants running continuous consumption are supported with scheduled bulk delivery.
- Annual contracts with scheduled call-off
- Second source held in reserve
How we supply Purified Terephthalic Acid
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. Colour (b-value), particle size and 4-CBA impurity level are critical to PET-chain quality — 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.
- Colour and particle size confirmed before we quote. Consistency matters to PET and fibre quality.
- Classification and documentation managed end to end. Labelling and carrier compliance confirmed before booking.
- Scheduled call-off scheduling. We hold contracted tonnage and release it against your consumption calendar.
- 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.
- Fibre-grade and bottle-grade both sourced. Matched precisely to your PET or polyester process.
Packed the way your plant receives it
Bag, bulk bag or bulk container — tell us your preferred format and we will quote and classify to it.
25 kg multi-wall bags
Moisture-barrier bags for smaller-volume orders, on pallets for easy handling.
500-1,000 kg jumbo bags
FIBC jumbo bags sized for mid-volume PET-plant orders.
Large-volume bulk shipment
Bulk container or hopper-car shipment for continuous-consumption PET and polyester 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.
Causes skin & eye irritation — standard dust precautions apply
PTA is a dry, free-flowing powder requiring standard chemical-handling precautions around dust exposure. The summary below is orientation only — the safety data sheet supplied with your specific batch is the authoritative document.
Classified hazards
H315Causes skin irritation.H319Causes serious eye irritation.H335May cause respiratory irritation.
Dust control recommended. Avoid dust generation and inhalation during transfer; always read the SDS issued with your specific batch and store accordingly.
Storage
Store in tightly closed containers in a cool, dry, well-ventilated area away from strong oxidising agents.
Handling
Use standard PPE (gloves, eye protection, dust mask) during transfer and weighing. Avoid dust generation; provide adequate ventilation when handling in bulk.
Transport
PTA typically ships under GHS pictogram GHS07 without a dedicated UN dangerous-goods number for standard industrial shipments; we confirm and document the 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, colour (b-value) and 4-CBA level confirmed against your process requirement 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 PTA becomes PET
PTA reacts with Mono Ethylene Glycol in a direct-esterification reaction: the carboxylic acid groups of PTA react with the hydroxyl groups of MEG, releasing water and building ester linkages that form the PET polymer chain. This direct-esterification route is now the dominant commercial process for PET worldwide, largely having displaced the older transesterification route that reacted Dimethyl Terephthalate (DMT) with MEG instead, releasing methanol rather than water.
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 | Aromatic dicarboxylic acid |
|---|---|
| Functional groups | Two carboxylic acid groups (para-substituted benzene ring) |
| Reactivity | Direct esterification with diols (PET); amidation with diamines (aramid-type polymers) |
| Related compounds | Mono Ethylene Glycol (co-monomer), Dimethyl Terephthalate (alternative monomer), PET Resin (polymer) |
Explore the wider petrochemical range
Purified Terephthalic Acid, answered
What is Purified Terephthalic Acid used for?
How is PTA related to PET and polyester?
Is Purified Terephthalic Acid hazardous?
What grade do you supply?
What packing do you offer?
Do you manufacture this yourself?
- Looking for the finished polymer? See our PET Resin page.
Get a quote on Purified Terephthalic Acid today
Send us your required grade, pack size and delivery window. We will come back with a firm quote, lead time and full documentation.