1,3-Diaminopropane · trimethylenediamine · DAP · Drums and IBCs
1,3-Propanediamine is ethylenediamine with one extra carbon in the middle, and that single carbon changes a surprising amount. The chelate ring it closes on a metal ion has six members rather than five, so it binds differently and selects differently. The extra methylene also separates the two nitrogens enough that each behaves more like an independent primary amine, which is why it is a cleaner intermediate for stepwise synthesis than EDA. It is a mobile, strongly basic, flammable liquid used mainly as a building block — for agrochemical and pharmaceutical intermediates, chelants, surfactants and crosslinkers. Chelora Amines supplies DAP in drums and IBCs, with a batch-wise COA and SDS on every dispatch.
36.03 + 10.08 + 28.01 = 74.13 g/mol
1,3-Propanediamine — 1,3-diaminopropane, trimethylenediamine, DAP — is a clear, colourless to pale yellow liquid with a strong ammoniacal odour, completely miscible with water and strongly alkaline. It is both corrosive and flammable, with a flash point in the mid-twenties Celsius, which puts it closer to ethylenediamine than to the heavier polyamines in handling terms.
It is used almost entirely as a building block rather than as a finished functional chemical. The main outlets are agrochemical and pharmaceutical intermediates, chelating agents, cationic surfactants and amidoamines, crosslinkers for waterborne polyurethane dispersions, and functionalising amines for ion-exchange and chelating resins. It cures epoxy quickly at a low ratio, though the short chain and sharp exotherm make it a specialist rather than a default hardener.
Where it earns its place against the cheaper ethyleneamines is in selectivity. The three-carbon spacer means a six-membered chelate ring, a different metal-binding profile, and two amines that behave more independently than EDA's do — which makes controlled mono-functionalisation considerably easier. If a synthesis specifies DAP, substituting EDA will usually not give a slightly different result; it will give a different compound.
| Chemical name | 1,3-Propanediamine |
| Common synonyms | DAP, 1,3-diaminopropane, trimethylenediamine, propane-1,3-diamine |
| CAS number | 109-76-2 |
| EC / EINECS number | 203-702-7 |
| HS / HSN code | 2921 29 (other acyclic polyamines; HSN 2921 29 on Indian invoices) |
| Molecular formula | C₃H₁₀N₂ (H₂N(CH₂)₃NH₂) |
| Molecular weight | 74.13 g/mol |
| Appearance | Clear, colourless to pale yellow liquid |
| Odour | Strong ammoniacal odour |
| Freezing point | About −12 °C |
| Boiling point | About 139–140 °C at atmospheric pressure |
| Density | About 0.888 g/cm³ at 20 °C |
| Solubility in water | Completely miscible; also miscible with alcohols and most polar organics |
| Amine value | About 1500–1520 mg KOH/g |
| Amine hydrogen equivalent weight | About 18.5 (four active hydrogens per molecule) |
| Flash point | About 24 °C (closed cup) — flammable liquid |
| UN number | Typically UN 2734, Amines, liquid, corrosive, flammable, n.o.s., Class 8 with subsidiary risk 3, Packing Group II — confirm against the SDS for the grade supplied |
Figures are typical values for the technical grade. The values for the material you order are stated on its Certificate of Analysis and Safety Data Sheet, which is also the controlling document for the transport classification.
Two strongly basic primary amines on a three-carbon spacer. The reactions are the standard primary amine set; the three-carbon spacing is what makes the products different from EDA's.
Both nitrogens coordinate the same metal ion, closing a six-membered ring. Binding is generally weaker than EDA's five-membered chelate but the selectivity across metals is different, which is the point.
M²⁺ + tn → six-membered chelateCarboxymethylation of all four N–H positions gives 1,3-propanediaminetetraacetic acid and related sequestrants with a different stability profile from EDTA.
DAP → PDTA (4 × –CH₂COOH)The extra methylene decouples the two amines electronically, so acylation, alkylation or carbamate formation on one nitrogen is easier to control than with ethylenediamine.
DAP + RX → mono-substituted amineReaction with chloroformates and related reagents gives propylcarbamate structures — the chemistry behind several carbamate agrochemical actives.
DAP + ClCO₂R → carbamateEach N–H adds across an epoxide ring. Four active hydrogens at an AHEW of about 18.5 give a ratio near ten parts per hundred of standard resin, with a fast cure and a sharp exotherm.
AHEW ≈ 18.5 · 4 active HCondensation with fatty acids gives amidoamines and, after ring closure, six-membered tetrahydropyrimidines rather than imidazolines — a different surfactant and inhibitor family.
DAP + RCOOH → amidoamineReacts rapidly with isocyanates to give substituted ureas, which is the basis of its use as a chain extender and crosslinker in waterborne polyurethane dispersions.
R–NCO + H₂N–R′ → ureaA strong aliphatic base — markedly stronger than any aromatic amine — forming salts readily with mineral and organic acids and acting as an acid scavenger.
DAP + 2 HCl → dihydrochlorideDAP is flammable as well as corrosive. With a flash point around 24 °C it needs a flammable liquid handling regime — bonding and earthing, ignition control, and the right electrical area classification — on top of the corrosive-liquid controls. If you are adding it to a store that holds DETA, TETA or TEPA, none of which are flammable liquids, check the area classification before the first delivery.
Discuss your storageThe usual industrial route adds ammonia across acrylonitrile and then hydrogenates the nitrile. Both steps are well established; the separation is where the work is.
Ammonia adds across the double bond of acrylonitrile to give 3-aminopropionitrile, with excess ammonia suppressing multiple addition.
The nitrile group is hydrogenated over a cobalt, nickel or Raney-type catalyst in the presence of ammonia, giving the primary diamine.
Excess ammonia and hydrogen are stripped and recycled and the catalyst separated from the crude amine stream.
Fractional distillation removes water, light ends, secondary amines and the cyclic by-products, taking the assay above 99%.
Product is filled under nitrogen into drums or IBCs, with the batch sampled for COA before release.
Chemists reach for DAP over EDA for reasons that are easy to state and easy to underestimate. First, chelation: a six-membered ring is less strained in some geometries but generally less stable than the five-membered ring EDA forms with first-row transition metals, and the ordering across different metals changes — so a sequestrant built on DAP has a different selectivity profile, not simply a weaker one. Second, independence: with three carbons between them, the two nitrogens influence each other far less, so protecting or functionalising one while leaving the other free is a cleaner operation. Third, ring size in cyclisation: condensations that would give a five-membered imidazoline from EDA give a six-membered tetrahydropyrimidine from DAP, with different stability and surfactant behaviour. If a specification names DAP, it usually names it for one of these three reasons.
DAP is hygroscopic and takes up carbon dioxide from the air readily, forming carbamate that consumes product and can deposit solids in lines and vents. Storage should be sealed and nitrogen-blanketed, with a carbon dioxide absorber on the vent of anything held for long periods. Colour drifts towards yellow on air exposure with little effect on reactivity, but it carries into pale products, so colour-sensitive users should specify an APHA limit. Because it is a flammable liquid, storage also needs bonding, earthing and ignition control. Carbon steel is generally suitable; stainless is preferred where colour matters. Avoid copper, copper alloys, aluminium and zinc throughout.
Assay, water and colour set the grade. For synthesis users the by-product amine profile usually matters more than the headline figure.
The working grade for chelant manufacture, surfactants, crosslinkers, epoxy curing and general synthesis.
Tighter limits on water, colour and by-product amines for pharmaceutical and agrochemical intermediate synthesis.
Highest purity for analytical, research and reference use, supplied in small sealed packs with full batch documentation.
| Parameter | Test method | Typical specification |
|---|---|---|
| Appearance | Visual | Clear liquid, free of suspended matter |
| Assay | GC | ≥ 99.0% w/w |
| Water | Karl Fischer | ≤ 0.5% w/w |
| Colour | APHA / Hazen | ≤ 25 |
| Density at 20 °C | Densitometer | 0.886 – 0.890 g/cm³ |
| Amine value | Potentiometric titration | 1500 – 1520 mg KOH/g |
| Refractive index at 20 °C | Refractometer | 1.459 – 1.463 |
| Total by-product amines | GC | ≤ 0.5% w/w |
| Non-volatile residue | Gravimetric | ≤ 0.05% w/w |
Indicative specification for planning. The controlling document is the Certificate of Analysis issued for your batch. High-purity requirements are quoted against your own specification sheet.
Mostly as an intermediate rather than a finished product — which means the volumes are smaller and the specifications tighter than for the bulk amines.
A building block for carbamate fungicides and several herbicide and plant-protection intermediates built on the propylenediamine skeleton.
Used in the synthesis of polyamine-containing actives, contrast media intermediates and a range of heterocyclic building blocks.
Carboxymethylated to PDTA and related sequestrants whose six-membered chelate ring gives a different metal selectivity from EDTA.
A chain extender and crosslinker for waterborne polyurethane dispersions, polyurea systems and reactive adhesives.
Amidoamine and tetrahydropyrimidine derivatives for inhibitor packages, cationic surfactants and asphalt emulsifiers.
Grafted onto polymer backbones as the functional amine in chelating resins and metal-scavenging sorbents.
A fast, low-ratio aliphatic hardener at an AHEW of about 18.5 — used where speed matters and the exotherm can be managed.
A standard bidentate ligand in coordination chemistry teaching and research, and a derivatisation reagent in several analytical methods.
A short list, but a technically demanding one — the value chain downstream of 1,3-propanediamine.
| Derivative | Made by | End use |
|---|---|---|
| Carbamate actives | Reaction with chloroformates and related reagents | Crop protection fungicides and intermediates |
| PDTA and related sequestrants | Carboxymethylation of the four N–H positions | Metal sequestration where EDTA's selectivity does not fit |
| Mono-substituted propanediamines | Controlled acylation or alkylation of one nitrogen | Pharmaceutical and specialty chemical intermediates |
| Tetrahydropyrimidines | Condensation with fatty acids and ring closure | Cationic surfactants, corrosion inhibitors, asphalt emulsifiers |
| Polyurea and PUD crosslinks | Reaction with isocyanate-terminated prepolymers | Waterborne polyurethane dispersions, adhesives, coatings |
| Chelating resin functional groups | Grafting onto a polymer or silica backbone | Metal recovery and removal in water and hydrometallurgy |
| DAP-cured epoxy networks | Stoichiometric cure of epoxy resin at AHEW ≈ 18.5 | Fast-setting adhesives, coatings and specialty systems |
Every container carries the Chelora Amines label with product name, grade, net weight, batch number, manufacturing date, UN number and hazard pictograms, including the corrosive and flame pictograms. Packs are sealed and nitrogen-blanketed.
Lined or lacquered steel drums under nitrogen, palletised and secured. The standard pack for batch consumers and synthesis users.
UN-approved composite or stainless IBCs for continuous users with a pump-out arrangement, bunding and ignition control.
250 mL to 2.5 L sealed containers for analytical, research and trial work, with full batch documentation.
DAP volumes are usually modest and the specifications tight, so most buyers take drums rather than bulk and qualify batch by batch. If you are running a registered synthesis, say so at enquiry stage — retained samples and extended impurity data can be arranged in advance rather than retrofitted. Export consignments are packed in UN-specification packaging with full dangerous goods documentation and shipped FOB, CIF or CFR through Nhava Sheva and Mundra.
Plan my supplyDAP causes severe skin burns and eye damage, is harmful if swallowed or inhaled, and is a flammable liquid. Volatility makes vapour exposure a real consideration — it boils at around 139 °C and has a noticeable vapour pressure at ambient temperature, and the odour is detectable well below any level you would want in a workplace. The notes below are a summary for planning only; always work to the Safety Data Sheet and your own site risk assessment.
| Parameter | Specification | Result |
|---|---|---|
| Appearance | Clear liquid | Complies |
| Assay (GC) | ≥ 99.0% | Complies |
| Water (KF) | ≤ 0.5% | Complies |
| Colour (APHA) | ≤ 25 | Complies |
| Density at 20 °C | 0.886 – 0.890 g/cm³ | Complies |
| Amine value | 1500 – 1520 mg KOH/g | Complies |
DAP is checked before dispatch. Because most of it goes into synthesis, the by-product amine profile often matters more to the buyer than the assay figure — ask for it and we will include it.
Five steps for a first order of DAP.
Grade, quantity, pack size, your water, colour and by-product limits, intended application and your delivery location.
We match technical or high-purity grade to the application, and discuss documentation if the end use is a registered synthesis.
We quote, then the batch is tested — assay, water, colour, density and amine value — and the COA and SDS are prepared.
Sealed, labelled drums or IBCs move under dangerous goods documentation for a corrosive liquid with a flammable subsidiary risk.
Material reaches your gate and repeat dispatches are scheduled to your usage, with retained samples where you qualify batch by batch.
Buyers who order DAP usually source these from the same list. See the full product range for the complete picture.
Short answers to what purchase, lab, EHS and plant teams ask us most. Anything else, ask us directly.
Send the grade, quantity, pack size, intended end use and your delivery address or destination port. We come back with a price, the documents that go with the batch and a dispatch or shipping plan, usually within 24 hours.