Buying tris(2-aminoethyl)amine (TREN, CAS 4097-89-6) is not like buying a commodity amine, and the reason is structural: TREN is a distilled speciality cut that shares its formula and its molecular weight with triethylenetetramine. Two offers can therefore both say "tetraamine, 98%" and be different products at very different prices. This guide covers what to put in the enquiry, how to read the specification, how to accept the delivery, and where the traps are.
Define Three Things Before You Ask for a Price
| Question | Why it changes the quote |
|---|---|
| What is it for? epoxy curing, chelation, gas treating, dendrimer synthesis | Epoxy and chelation work needs the isomer basis stated; a surfactant or intermediate use may tolerate a broader cut |
| How much, in what pack? 1 kg sample, 25 kg jerrican, 200 kg drum | This is a speciality product with real small-volume demand – pack size drives both price per kg and the paperwork |
| What documentation? COA only, or COA plus isomer distribution, colour limit, origin statement | Batch documentation is issued against the specification you agree; asking afterwards is how disputes start |
If you cannot answer the first question yet, ask for a 1 kg sample with COA. It is a normal request for this product and it is cheaper than discovering the isomer issue during a production trial.
Reading the Specification
| Line item | What good looks like | What it tells you |
|---|---|---|
| Appearance | Pale yellow to colourless liquid | Darker than the previous batch means oxidation or CO2 pickup, even if the assay passes |
| Purity (GC) | 98.0% min | Distilled product. Ask what the 2% is – linear tetraamine, higher oligomers or water |
| Moisture (KF) | 0.5% max | The cheapest proxy for how well the drum has been kept sealed |
| Nitrogen content | 38.3% theoretical (calculated) | Cross-check: 4 x 14.007 / 146.23 |
| Amine equivalent weight | 24.4 g/eq theoretical (calculated) | Cross-check for functionality: 146.23 / 6 |
| Isomer basis | Branched tetraamine, stated | The line that separates TREN from a relabelled TETA cut |
Do not accept a total-nitrogen titration as the assay. Nitrogen titration cannot distinguish TREN from TETA, DETA or EDA, and all four give a plausible-looking number. A GC assay with an isomer statement is the only specification line that actually identifies this product.
What to Put in the Enquiry
| Field | Example |
|---|---|
| Product and CAS | Tris(2-aminoethyl)amine, CAS 4097-89-6 (specify "branched isomer") |
| Quantity and pack | 5 kg for trial, then 200 kg drums monthly |
| Assay basis | 98.0% min by GC, isomer distribution on COA |
| Water limit | 0.5% max by Karl Fischer |
| Application | Room-temperature epoxy hardener for a thin-film coating |
| Delivery | FOB or CIF, destination port, required documentation |
The application line matters commercially, not just technically: an epoxy buyer and a chelate-synthesis buyer can be quoted different grades of the same CAS, and stating the use gets you the right one the first time.
Packaging and Repackaging
- 200 kg steel or HDPE drum – the production pack. Ask for nitrogen blanketing and confirm the gasket material is amine-resistant.
- 25 kg jerrican or drum – workshop-scale use, easier to keep sealed once opened.
- 1 kg and 5 kg – development and pilot packs. Normal for this product, not a special favour.
- Repackaging: if you decant, do it under dry nitrogen, into clean dry containers, labelled with product, CAS, batch and date. TREN is corrosive and colourless-to-pale-yellow; an unlabelled container of it is an accident waiting to be scheduled.
Because the main degradation route is CO2 and moisture pickup rather than freezing or settling, headspace management beats warehouse temperature. A part-used drum with 40 litres of air above the liquid will be a different product in six months.
Acceptance Testing on Arrival
| Test | Method | Acceptance |
|---|---|---|
| Appearance and colour | Visual against previous retained sample | Pale yellow to colourless; no haze, no sediment |
| Water | Karl Fischer | 0.5% max |
| Assay | GC, with isomer statement | 98.0% min, branched |
| Identity check | Calculated nitrogen and amine equivalent weight against the COA | 38.3% N, 24.4 g/eq – consistent with the stated assay |
| Drum condition | Visual and weight | Seals intact, no weeping, gross weight matches label |
Retain a sample of every batch. For a product where a 2% isomer difference is invisible on the COA, the retained sample is the only evidence you will have in a dispute – and it is also how you notice a slow drift in colour across deliveries.
Storage and Handling Discipline
- Seal and blanket. Dry nitrogen, closed drums, use in rotation; do not store part-used drums open in a humid plant.
- Keep away from acids and oxidisers. The reaction with acid is violent enough to be a relief-system design case.
- Do not put it in copper, brass or aluminium. Stainless steel, HDPE and PTFE are the materials of construction.
- Nitrosamine discipline. TREN is a tertiary amine; keep it away from nitrites and nitrosating agents in both process and waste streams.
- Transport. Shipped as a corrosive amine under the UN entry and packing group stated on the current SDS – confirm the entry with your forwarder rather than inferring it from the CAS number.
Four Traps Worth Knowing
- The "tetraamine" label. A price that is unexpectedly close to TETA is not a bargain; it is usually a linear-rich cut. Ask for the isomer basis.
- The nitrogen titration COA. Looks authoritative, identifies nothing. Insist on GC.
- Water inside specification, colour outside expectation. Water measurement can pass while the drum has taken up CO2; use colour and haze as the second signal.
- Small-volume pricing. TREN is traded in kilograms for development and in drums for production; comparing a 1 kg price with a drum price is comparing two different markets.
Frequently Asked Questions
What is the minimum order quantity for TREN?
Development quantities start at 1 kg. Standard packs are 1 kg, 5 kg, 25 kg and 200 kg, each with a batch COA and the current SDS.
Can you confirm the isomer distribution on the COA?
Yes, if it is asked for at enquiry stage. It is the specification line that distinguishes genuine TREN from a broader tetraamine cut, and it is worth writing into the purchase order.
How is TREN shipped?
As a corrosive amine under the UN entry and packing group given on the current SDS, in UN-approved packaging, FOB or CIF against destination. We confirm the classification with the forwarder for each shipment.
Do you supply comparison products for trials?
TETA, DETA and EDA can be quoted on request alongside TREN, which is useful when the trial is a selection exercise rather than a substitution.
References and Disclaimer
- PubChem CID 77731 – formula, molecular weight and computed properties for tris(2-aminoethyl)amine.
- Acceptance limits in this guide follow the standard commercial specification (98.0% min GC, water 0.5% max); a buyer’s own specification takes precedence where it is stricter.
Disclaimer: commercial and technical guidance for industrial buyers, not a specification or SDS. Always handle the material according to the supplier’s current SDS and your local regulations.
PolyBlueChem supplies tris(2-aminoethyl)amine (TREN, CAS 4097-89-6) at 98.0% min GC with 0.5% max water, from 1 kg development packs to 200 kg drums, with per-batch COA and SDS. Send the application, pack size and documentation you need and we will return a firm quotation. See the TREN product page or contact us directly.