Are DMA-18 and ADMA18 always the same commercial grade?

Both names are associated with octadecyldimethylamine, CAS 124-28-7. ADMA18 has been used as an industrial trade name. Matching names do not establish identical C18 fractions, chain profiles, amine-quality specifications or physical form. The quoted grade specification and test methods define the comparison.

Is DMA-18 a finished quaternary ammonium surfactant?

No. DMA-18 is a tertiary fatty amine intermediate. A quaternary ammonium compound has a different nitrogen structure and a counterion. A process requiring a reactive amine feedstock therefore has different selection requirements from a formulation using an already quaternized surfactant.

Octadecyldimethylamine (DMA-18) CAS 124-28-7

Octadecyldimethylamine (DMA-18, CAS 124-28-7, EC 204-694-8) is N,N-dimethyloctadecan-1-amine, a long-chain tertiary fatty amine with the molecular formula C20H43N. It is used as a reactive intermediate for quaternary ammonium compounds, amine oxides, surfactants and other specialty derivatives. Commercial grades can differ in tertiary-amine content, carbon-chain distribution, residual primary and secondary amines, total amine value, water, color and physical form. TDS, COA and SDS are available for grade specifications and handling guidance, with packaging specified for the selected material and process requirements.

CAS: 124-28-7
Synonyms: N,N-Dimethyloctadecan-1-amine; N,N-Dimethyloctadecylamine; Octadecyldimethylamine; Dimethyl stearamine; Stearyldimethylamine; DMA-18
Einecs: 204-694-8
Molecular Formula: C20H43N
Grade: Industrial tertiary fatty amine; C18 fraction, alkyl-chain profile and amine-quality specifications stated for the quoted grade
Package: Compatible industrial containers; packing and net weight stated in the quotation

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Product Description

1 Product overview

2 Technical information

3 Quality control and analytical methods

4 Related raw materials and surfactants

5 Handling and documentation

Product overview

The principal C18 molecule has one octadecyl group and two methyl groups attached to nitrogen, with formula C20H43N and EC 204-694-8. Commercial DMA-18 grades can contain minor shorter-chain homologues. The C18 fraction and total tertiary-amine content describe different aspects of the grade and are reported separately.

Technical information

Product	Octadecyldimethylamine (DMA-18) CAS 124-28-7
CAS number	124-28-7
EC / list number	204-694-8
Molecular formula / identity	C20H43N
Synonyms	N,N-Dimethyloctadecan-1-amine; N,N-Dimethyloctadecylamine; Octadecyldimethylamine; Dimethyl stearamine; Stearyldimethylamine; DMA-18
Grade	Industrial tertiary fatty amine; C18 fraction, alkyl-chain profile and amine-quality specifications stated for the quoted grade
Packaging	Compatible industrial containers; packing and net weight stated in the quotation

Quality control and analytical methods

Gas chromatography (GC) can assess the alkyl-chain profile and chromatographic assay. GC area percentages are not automatically mass percentages: the calculation basis and any calibration matter. Amine titration measures basic amine functionality, so its result is not interchangeable with GC assay. Grade evaluation covers total and tertiary amine values, residual primary and secondary amines, water and color. Karl Fischer water testing requires a method suitable for the amine matrix, including the reagent medium and endpoint conditions.

Related raw materials and surfactants

Octadecylamine (stearylamine) is a C18 primary amine with N-H bonds and different reaction chemistry from DMA-18. Steartrimonium chloride (STAC) is a finished C18 quaternary ammonium surfactant with a counterion. These products address different process requirements and are not direct substitutes for the tertiary amine.

For manufacturing routes based on fatty-alcohol amination, stearyl alcohol is a C18 feedstock rather than the finished DMA-18 intermediate. Buyers seeking an already oxidized surfactant can consider lauramine oxide (LDAO). Its commercial chain profile and solution composition are grade-dependent; it is not the C18 amine oxide obtained from DMA-18.

Handling and documentation

DMA-18 can solidify in cooler conditions and become liquid under suitable temperature conditions. Physical form and any warming or homogenization instructions depend on the grade. The quotation states packing and net weight; the product SDS covers storage, protective equipment and transport precautions. Packaging photographs illustrate container types and do not establish stock or batch condition.

We can provide the Certificate of Analysis (COA), Technical Data Sheet (TDS), Safety Data Sheet (SDS), GC chromatograms and applicable quality-test information for DMA-18. The quoted specification and analytical reporting basis support grade comparison. For a quotation, send the required quantity, application or grade requirements, and destination.

FAQ - Technical & Supply Chain

Q:
Are DMA-18 and ADMA18 always the same commercial grade?

A: Both names are associated with octadecyldimethylamine, CAS 124-28-7. ADMA18 has been used as an industrial trade name. Matching names do not establish identical C18 fractions, chain profiles, amine-quality specifications or physical form. The quoted grade specification and test methods define the comparison.
Q:
Why can GC assay and amine titration give different results?

A: They measure different characteristics. GC separates components and reports an assay or chain profile on a stated calculation basis. Amine titration measures basic amine functionality. GC area percentage, mass percentage and titration results are not interchangeable without the relevant method and reporting basis.
Q:
Is DMA-18 a finished quaternary ammonium surfactant?

A: No. DMA-18 is a tertiary fatty amine intermediate. A quaternary ammonium compound has a different nitrogen structure and a counterion. A process requiring a reactive amine feedstock therefore has different selection requirements from a formulation using an already quaternized surfactant.

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