Cyclohexylamine CAS 108-91-8

What is Cyclohexylamine?

Cyclohexylamine is a primary amine on a saturated six-membered ring — the fully hydrogenated counterpart of aniline, C₆H₁₁NH₂. That relationship is not just structural: most of the world's cyclohexylamine is made by hydrogenating aniline.

Replacing the aromatic ring with a saturated one changes the chemistry completely. Aniline's nitrogen lone pair is delocalised into the ring, which makes it a weak base and a poor nucleophile. Cyclohexylamine's is not, so it behaves as a strong, ordinary aliphatic base — but with the bulk and the lipophilicity of a ring system rather than a floppy chain.

It is a clear, colourless to pale-yellow liquid boiling at about 134 °C, with a strong fishy, ammoniacal odour. The flash point sits near 31 °C. Unusually for a molecule with six carbons it is fully miscible with water, which is a direct consequence of the compact ring shape and is central to its largest application.

Commercially, cyclohexylamine has three substantial markets. It is one of the standard neutralising amines for boiler and steam condensate systems, where its volatility and water miscibility let it travel with the steam and raise condensate pH. It supplies the cyclohexylamino group to a major class of sulfenamide tyre accelerators. And it is the starting point for cyclamate sweeteners in the markets where those remain permitted.

Why cyclohexylamine specifically

• Volatile and water-miscible at once. It travels with steam and dissolves in the condensate it meets, which is exactly what a neutralising amine has to do. Few bases of this strength manage both.
• A strong base from a ring. Unlike aniline, the nitrogen lone pair is not delocalised, so it behaves as a full aliphatic base while carrying ring bulk and lipophilicity.
• Sulfenamide accelerator chemistry. The cyclohexyl group gives a benzothiazole sulfenamide a distinct cure profile — one of the standard delayed-action accelerators in tyre compounding.
• Favourable distribution ratio in steam. Its partitioning between steam and water determines how far down a condensate system it protects, and that ratio is why it is blended with other amines rather than used alone.

How CHA is Manufactured

Cyclohexylamine is made predominantly by hydrogenating aniline, with a secondary route from cyclohexanol. The aniline route dominates and leaves a characteristic impurity profile.

• Aniline hydrogenation. Aniline is hydrogenated over a cobalt, nickel or ruthenium catalyst at elevated temperature and pressure. The aromatic ring is saturated to give cyclohexylamine, with dicyclohexylamine forming as the principal co-product.
• Selectivity control. Catalyst choice and conditions decide the ratio of cyclohexylamine to dicyclohexylamine. Plants generally run for one or the other and recycle or sell the co-product, since both have real markets — dicyclohexylamine has its own role in rubber chemicals.
• Alternative route. Some capacity aminates cyclohexanol with ammonia over a supported catalyst. This gives a different trace profile, with residual cyclohexanol rather than residual aniline.
• Separation and finishing. The product is separated by fractional distillation and taken to specification, then filled into drums, IBCs or tanks with nitrogen blanketing where colour matters.

Typical Commercial Specification

Figures below are representative of standard commercial grade. Boiler-treatment and rubber-chemical grades with tighter aniline and secondary amine limits are available — send us the specification you work to and we will quote against it.

Physical & Chemical Properties

Reactivity in practice

The nitrogen behaves as a full aliphatic primary amine, with the saturated ring supplying bulk and lipophilicity:

• Sulfenamide formation. Reaction with benzothiazole disulphide or sulfenyl chloride chemistry gives the cyclohexyl-substituted delayed-action accelerators used in tyre compounding.
• Sulfamation. Reaction with sulphur trioxide or sulphamic acid chemistry gives cyclohexylsulphamate — the cyclamate sweetener, where permitted.
• Acid-base and neutralisation chemistry. As a volatile strong base it neutralises carbonic acid in steam condensate, raising pH and reducing carbonic acid corrosion in return lines.
• Amide, urea and dithiocarbamate formation. Reaction with acid chlorides, isocyanates and carbon disulphide gives the derivatives used in crop protection, corrosion inhibition and rubber chemistry.

Cyclohexylamine vs Aniline and Related Amines

Cyclohexylamine is most usefully understood against aniline, from which it is made, and against the other neutralising amines it is blended with in steam treatment. The difference between a saturated and an aromatic ring is the whole story in the first comparison, and volatility is the whole story in the second.

Stated plainly: aniline and cyclohexylamine differ by six hydrogens and behave like different classes of compound — aniline is a weak base because its lone pair is tied up in the ring, cyclohexylamine is a strong one because its is not. In steam treatment, cyclohexylamine's high distribution ratio carries it far down a condensate system while morpholine protects closer to the boiler, which is why treatment packages blend them rather than choosing one.

Industries We Supply CHA To

The same molecule leaves our warehouse for very different factories. What changes between them is not the CAS number but the grade — particularly residual aniline — and the documentation each sector expects.

Where CHA is Used

Cyclohexylamine has three substantial markets and a long tail of smaller ones. These are the end uses our customers buy it for, roughly in order of volume.

In boiler and condensate treatment

Carbon dioxide carried over with steam dissolves in condensate to form carbonic acid, which attacks return lines from the inside. A neutralising amine fixes this by travelling with the steam and raising the pH of the condensate wherever it forms. Cyclohexylamine is one of the standard choices because it is both volatile enough to distribute with steam and miscible enough with water to dissolve in the condensate it meets. Its distribution ratio is high, which means it carries far down a system — so it is usually blended with morpholine, which protects closer to the boiler, rather than used alone. Where the steam contacts food or feed, the treatment chemical has to be approved for that service at destination.

In tyre and rubber chemicals

Cyclohexylamine combined with benzothiazole chemistry gives a delayed-action sulfenamide accelerator — one of the standard choices alongside the tert-butyl analogue. The cyclohexyl group gives its own balance of scorch safety and cure rate, and compounders select between the two on processing requirements rather than interchangeably. Water content on the incoming amine matters, since the sulfur intermediates hydrolyse readily.

In sweetener manufacture

Sulfamation of cyclohexylamine gives cyclohexylsulphamate, isolated as the sodium or calcium salt — the cyclamate sweeteners. Their regulatory status varies substantially by territory: permitted in many markets, not permitted in others. Anyone buying for this use needs food-grade material with tightly controlled residual aniline and a confirmed regulatory position at destination before importing.

In corrosion inhibition

Beyond steam systems, cyclohexylamine salts serve as neutralising inhibitors in refinery overhead service and, historically, as vapour-phase inhibitors that sublime into sealed packaging to protect metal parts in transit. Note that nitrite-based vapour-phase chemistry brings an amine and a nitrosating agent together, which needs a deliberate risk assessment.

Quality Control & Testing

Every lot is released against a batch-specific Certificate of Analysis. The methods behind the numbers are standard across the industry, and we are happy to share them or to work to your own in-house test protocol.

• Assay and amine distribution — gas chromatography, which resolves cyclohexylamine from dicyclohexylamine and quantifies residual ammonia and cyclohexanol.
• Residual aniline — a dedicated, sensitive GC or HPLC determination. This is the most important single test on aniline-route material and should be reported on the batch certificate, not inferred from a typical sheet.
• Water content — Karl Fischer titration, which matters directly in sulfenamide manufacture.
• Colour — APHA / Hazen against a standard. Colour drift signals air ingress or metal contamination.
• Distillation range — a fast, revealing check for secondary amine and moisture carry-over.
• Metals and residue — iron and evaporation residue, both of which matter in boiler treatment and fine chemical service.

Common Process Problems & Likely Causes

When cyclohexylamine misbehaves in a plant, the cause is usually one of a short list of things. This table is the shortcut our technical desk works through before anyone opens a complaint file.

Packaging, Storage & Shipping

• Standard packing. 180 kg net in lined steel or HDPE drums, with 1000 L IBCs for larger users.
• Bulk packing. Road tankers and ISO tank containers for water treatment formulators and continuous plants.
• Inert blanketing. Nitrogen-blanketed at fill where the grade and end use call for it, to protect colour and limit carbon dioxide pickup.
• Storage. Cool, dry, well-ventilated and bunded area away from heat, ignition sources, oxidisers and acids, with containers kept tightly closed.
• Materials of construction. Stainless steel, carbon steel or suitable lined vessels. Avoid copper, brass, bronze, aluminium and mercury, all of which are attacked by amines.
• Shelf life. Typically 12 months in unopened original packing under those conditions. Beyond that, re-test rather than assume.
• Reproductive hazard handling. Cyclohexylamine is classified in several systems as suspected of damaging fertility. Exposure control and the associated workplace risk assessment should reflect that rather than treating it as a routine corrosive.
• Transport classification. UN 2357, Cyclohexylamine, Class 8 corrosive with subsidiary risk 3 flammable, Packing Group II — shipped with full dangerous-goods documentation.
• Container loading. Palletised and secured for FCL; LCL consolidation and tank arrangements available by volume.

Hazards & Safe Handling

Cyclohexylamine is corrosive, flammable and classified in several systems as a suspected reproductive hazard. It must be handled by trained personnel under a proper risk assessment. The classifications below are indicative — the current SDS supplied with your consignment is the governing document.

• Reproductive hazard. Classified in several systems as suspected of damaging fertility. This should shape the workplace risk assessment, the exposure controls and any policy on who works with the material, rather than being treated as a routine corrosive hazard.
• Exposure control. Handle in a closed system or under local exhaust ventilation. Both inhalation and skin absorption are meaningful routes with this product.
• PPE. Chemical-resistant gloves, chemical goggles and face shield, chemical-resistant clothing, and respiratory protection suited to the task.
• Ignition control. The flash point is near 31 °C, so a warm process area or heated transfer line can put the headspace into the flammable range. Keep away from heat and ignition sources and classify the zone accordingly.
• Incompatibilities. Strong oxidising agents, strong acids, acid chlorides, nitrites, mercury, and copper, brass, bronze and aluminium equipment.
• Spill response. Eliminate ignition sources and ventilate. Contain, absorb with inert non-combustible material and collect in a labelled closed container. Do not wash to drain.
• Fire. Use alcohol-resistant foam, dry chemical or carbon dioxide; cool exposed containers with water spray. Decomposition releases nitrogen oxides — use self-contained breathing apparatus.
• First aid. Remove contaminated clothing immediately, wash skin with plenty of water, flush eyes for at least 15 minutes, move to fresh air, and seek medical attention with the SDS to hand.

Regulatory & Compliance Notes

Cyclohexylamine is a long-established industrial chemical listed on the major national chemical inventories, but it carries more regulatory weight than most amines of its size: a reproductive hazard classification, a food-additive dimension through cyclamates, and a boiler-treatment dimension where steam contacts food. The notes below are orientation rather than legal advice — confirm your own position with your regulatory adviser before importing.

• Inventory status. Listed on the principal chemical inventories in the major importing regions. Ask us for the inventory confirmation relevant to your destination country.
• Import registration. Several territories require the importer to hold a registration or notification before a consignment lands. Start that process early — it is the most common cause of delay at destination.
• Hazard communication. Supplied with an SDS compliant with the format applicable to your region, and labelled in line with the GHS classification for the product.
• Reproductive hazard classification. Classified in several systems as suspected of damaging fertility. This affects labelling, workplace controls and, in some jurisdictions, authorisation and substitution obligations. Build it into your assessment at the design stage, not at the audit.
• Steam that contacts food or feed. Where cyclohexylamine is used to treat boiler water producing steam that contacts food, feed or pharmaceutical product, the treatment chemical must be approved for that service at destination. Permitted lists and concentration limits differ by territory.
• Cyclamate end use. Cyclamate sweeteners are permitted in many markets and not permitted in others. If the material is destined for sweetener manufacture, confirm the regulatory position at destination and expect food-grade specifications with tightly controlled residual aniline.
• Dangerous goods. UN 2357, Cyclohexylamine, Class 8 corrosive with subsidiary risk 3, Packing Group II. Declarations prepared for IMDG (sea) or IATA (air) as appropriate to the mode.

We Supply CHA Worldwide

Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Cyclohexylamine from India to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation, dangerous-goods paperwork and freight so the material arrives ready to use.

• Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
• Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other Indian ports arranged where it suits the routing.
• Documentation. Commercial invoice, packing list, certificate of origin, COA, SDS and dangerous-goods declaration issued as a complete set.
• Flexible volumes. A single drum for laboratory qualification, through LCL consolidations, up to repeat full loads on a supply contract.
• Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.

Buying CHA from Chelora

We are an independent sourcing and supply partner. For cyclohexylamine that means two things before anything else: establishing the residual aniline limit your application needs, and confirming whether the end use is food-adjacent — because both decide which producer and which route the material should come from.

• Documentation on every lot. Batch-specific COA including residual aniline, current SDS and TDS issued with the consignment.
• Samples before commitment. Trial quantities for process qualification ahead of a commercial order.
• Quantities. From a single 180 kg drum through to tank loads and ongoing contract supply.
• Export experience. Class 8 dangerous-goods documentation, packing and labelling handled for sea and road freight.
• Technical support. Direct access to people who know the chemistry, for questions on aniline limits, steam distribution ratio or materials compatibility.
• Related intermediates. Aniline, morpholine, diethylethanolamine, tert-butylamine and the wider amine range from one supplier.

How ordering works

• Send the enquiry. Product, grade or specification, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
• We quote. Price, lead time, packing and a sample COA, normally within one working day.
• Sample and qualify. For first orders or critical applications, we send a trial quantity so your lab can sign off before you commit.
• Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
• Production and QC. Material allocated and released against a batch-specific COA, with a pre-shipment sample where the application calls for it.
• Ship and document. Packed, labelled and loaded with the full export and dangerous-goods document set, and tracked through to arrival.

Related Amines & Intermediates

Buyers of cyclohexylamine usually source several of these alongside it. Consolidating them on one order cuts freight cost and gives you a single point of contact for documentation.