Fatty Acid Diethanolamide (6501)

Product Overview

Fatty Acid Diethanolamide (coconut diethanolamide, type 6501) is the workhorse foam stabilizer and oil emulsifier of alkaline and neutral cleaning chemistry. It is made from coconut fatty acids reacted with diethanolamine, and plating suppliers stock it because a degreasing tank that only has a strong anionic surfactant foams high and rinses thin - the amide thickens and stabilizes the foam, lifts buffing compound and mineral oil into the emulsion, and helps the cleaner wet recessed zipper sliders and buckles. Type 6501 refers to the 1:1 or 1:1.5 amide ratio; the 1:1.5 type is a mobile liquid at room temperature and is the most common for cleaning blends. Market grades differ by acid value, amine value and color: a quality 6501 is light yellow and nearly odorless, while cheap, over-heated lots are dark amber, smell of amine and leave oily streaks on rinsed parts. QLQ selects the light-colored 1:1.5 grade with a controlled free-amine level so it never stains brass or copper pre-plate surfaces.

Product Identity (Encyclopaedia Card)

What it is and what it does. Fatty acid diethanolamide (known as 6501) is the non-ionic foam booster and thickener of cleaners and degreasers, and the emulsifier that keeps oily soil dispersed in the cleaning bath.

• Pale yellow viscous liquid, made from coconut fatty acid; it is the most common foam booster in the trade.
• Improves soil emulsification, so oily soils rinse away instead of redepositing.
• Also used to thicken liquid detergents and to stabilise foam in hand cleaners.

Typical Use in a Plating / Finishing Line

Safety, Handling & Storage

Quality Documents Shipped With Every Batch

Buyer Questions We Answer Every Week

How It Works in a Degreasing Tank

Diethanolamide sits at the oil-water boundary and does three jobs at once. It stabilizes foam so the air or cathode gas keeps scrubbing oils off the work; it emulsifies buffing wax and mineral oil into fine droplets that rinsing can remove; and it thickens the solution slightly, which slows drainage and gives the alkali more contact time on vertical surfaces. It is rarely used alone - the classic low-cost soak cleaner is a 6501 + caustic/phosphate builders + anionic surfactant blend:

Used directly as a tank additive (rather than in a bought concentrate), 6501 is dosed at roughly 0.5-2 g/L into an operating soak cleaner at 60-80°C, with co-surfactant adjusted to avoid over-foaming. The amide is consumed by drag-out and by oil loading, not by current, so additions follow weekly titration or water-break checks.

Quality Checks Before Use

How QLQ controls it: every 6501 lot is checked for acid value, amine value, color and rinse-film behavior on brass panels before release, and the batch number is kept traceable. A high free-amine lot can leave a faint yellow tint on bright copper and brass - the exact failure that QLQ's retained-sample check catches before material reaches your tank.

Common Problems & Fixes (Workshop Table)

Handling & Safety

• Health: mildly irritating to skin and eyes; wear gloves and goggles. The product is alkaline - rinse splashes with water.
• Nitrosamine note: diethanolamide chemistry can form nitrosamines if combined with nitrite-based inhibitors. Keep it out of nitrite-containing rust-preventive tanks and use nitrite-free formulas where possible.
• Dosing: the material is viscous; warm the drum and dose by weight into a stirred tank, never splash cold lumps into hot alkali.
• Storage: keep drums sealed and cool. Long storage above 40°C darkens the product and raises the amine value; the recommended shelf life sealed is 12 months.
• Waste: spent emulsified cleaner is an oil-in-water emulsion - break it with acid and coagulant in the effluent plant before discharge; do not dump straight to drain.

What It Does on Iron, Zinc Alloy, Copper and Stainless Steel Parts

FAQ

Cleaning stage giving you skip-plating or oil films? QLQ engineering helps shops in 10+ countries rebuild degreasing chemistry from a tank photo and water analysis. Contact us.