What Is Erucamide?
Erucamide, also known as erucic acid amide or cis-13-docosenamide, is a long-chain primary fatty amide. It is produced by reacting erucic acid, which is recovered from rapeseed (canola) oil, with ammonia; the resulting amide is a mono-unsaturated C22 molecule carrying one cis double bond. The double bond is the reason erucamide stays soft and mobile at the surface of a polymer film instead of crystallising into a brittle layer like a fully saturated stearamide.
| Property | Typical value |
|---|---|
| CAS number | 112-84-5 |
| Molecular formula | C22H43NO |
| Molecular weight | About 337.6 g/mol |
| Chemical name | cis-13-docosenamide |
| Appearance | White to off-white powder, pastille or flake with a waxy feel |
| Melting range | Approximately 76-83 degrees C |
| Solubility | Insoluble in water; soluble in warm alcohols, esters and aromatic solvents |
| Amide content | 98 percent minimum |
| Acid value | 2 mg KOH/g maximum |
| Iodine value | About 75 g I2/100 g, calculated from one double bond |
Because the molecule is only slightly compatible with polyethylene and polypropylene, it does not stay locked in the polymer matrix. It migrates steadily towards the surface - a behaviour the industry calls blooming - and that controlled migration is exactly what makes it useful.
How Erucamide Works as a Slip Agent
When erucamide is compounded into a polyolefin film or sheet, it slowly diffuses to both surfaces and forms a thin lubricating layer. Two film surfaces then slide over each other instead of gripping, so the coefficient of friction (COF) falls sharply. This is measured as static and kinetic friction by ASTM D1894, and slip-grade film is normally specified at a kinetic COF below roughly 0.3 depending on the end use.
Typical dosage: about 500-2,000 ppm erucamide for polyethylene and polypropylene packaging films
Bloom time: 24-72 hours after extrusion, so slip builds gradually; freshly wound rolls are still tacky
Dosing form: powder for compounding, or masterbatch concentrate for accurate low-dose addition on the film line
Trade-offs: excessive dosage can reduce heat-seal strength, print adhesion and hot-tack, and may cause plate-out on chill rolls
Temperature: migration accelerates at higher storage temperature, which shortens the time to reach slip but also raises the risk of over-slipping
For this reason a slip package is designed as a balance: enough erucamide to guarantee unwinding and bag opening, but not so much that printing inks or laminating adhesives lose their grip. Many converters use a blend of erucamide with a saturated amide such as stearamide or behenamide, because the saturated amide migrates faster and gives early slip while erucamide provides durable, longer-lasting slip.
Anti-Blocking, Printing Inks, Coatings and Adhesives
Blocking is the tendency of stacked film layers or printed sheets to stick together under pressure and warmth. Erucamide lowers the blocking load measured by ASTM D3354, and in demanding film structures it is combined with inorganic anti-block agents such as silica, talc or zeolite that create microscopic surface roughness. The combination lets high-speed form-fill-seal machines, bag-making lines and automatic packaging equipment run without misfeeds or torn film.
In the printing and ink industry erucamide works as a matting agent and anti-blocking additive. It adjusts the surface gloss of printed matter for a matte, low-sheen appearance, and it stops ink-coated sheets and labels from sticking together in stacks during storage and transport so that magazines, cartons and label reels separate cleanly on press and in finishing equipment.
In coatings and adhesives the amide improves surface slip and abrasion resistance, raising scratch and mar resistance of clear and pigmented films, and it modifies viscosity and flow so adhesives wet and bond reliably to metal, plastic and paper substrates. Typical loading in these systems is lower than in film, because the additive is concentrated in a thin surface layer.
Textile, Leather and Other Applications
In textiles and leather erucamide is used as a finishing agent. It improves the smoothness and softness of fabrics and leather, lifts hand feel, and imparts a degree of anti-static behaviour that reduces the attraction of dust and lint - a practical benefit for upholstery, automotive interior trim and technical textiles that must stay clean in service.
Rubber and plastics processing: lubricant, mould release aid and flow improver for compounds
Pigment and filler systems: dispersing aid that keeps particles from agglomerating
Wax blends and polishes: slip and gloss control for coatings and polishes
Masterbatch and compound carriers: additive for PE and PP grades sold as slip-modified resins
Consumption is governed by the surface area of the finished article rather than its weight, which is why thin films require proportionally more additive than thick mouldings.
Quality Control, Packaging and Storage
Erucamide is a low-melt organic solid, so a lot certificate normally covers amide content, acid value determined by titration in line with ISO 660 or an equivalent method, iodine value to confirm the degree of unsaturation, colour in Gardner or Pt-Co units, and melting range. Consistent acid value and colour are the two parameters that most often decide whether a lot performs on a film line without plate-out.
| Item | Typical practice |
|---|---|
| Packaging | 25 kg multi-wall paper bags with PE liner, or 500-1,000 kg big bags |
| Storage | Cool, dry warehouse below 30 degrees C, away from direct sunlight and odour-sensitive goods |
| Shelf life | About 24 months in unopened packaging |
| Handling | Avoid dust generation and prolonged skin exposure; keep away from strong oxidising agents |
| Documentation | Lot-traceable certificate of analysis and safety data sheet supplied with each shipment |
Grades intended for food-contact films are produced against the food-contact regulations of the destination market, and the converter remains responsible for verifying that the final article meets the applicable migration limits for the intended use.
Frequently Asked Questions
Q: What is erucamide used for?
A: It is mainly used as a slip agent and anti-blocking additive in polyolefin films, and also as a matting agent in inks, a slip and mar additive in coatings and adhesives, and a softener in textile and leather finishing.
Q: What is the CAS number of erucamide?
A: CAS 112-84-5; its molecular formula is C22H43NO and its molecular weight is about 337.6 g/mol.
Q: How much erucamide is added to a polyethylene film?
A: Typically 500-2,000 ppm, adjusted to the film thickness, the required coefficient of friction and the print or seal performance the packaging must achieve.
Q: How long does erucamide take to work?
A: Because it must migrate to the surface, full slip normally develops over 24-72 hours after extrusion; warm storage accelerates blooming, cold storage slows it.
Q: Can erucamide be used with other additives?
A: Yes. It is often blended with saturated amides for faster early slip and with silica or talc anti-block agents, provided total additive levels are balanced against heat-seal and print performance.
Q: How should erucamide be stored?
A: Keep bags sealed in a cool, dry place below about 30 degrees C, avoid direct sunlight and strong oxidisers, and use within roughly 24 months of production for consistent slip performance.