Dimethyldioctadecylammonium chloride, or distearyl dimethyl ammonium chloride, is a quaternary ammonium salt consisting of a nitrogen atom substituted with two methyl groups and two octadecyl groups. The long-chain hydrocarbon groups combined with the ionic nature of the amine group enables it to act as a surfactant

Surfactant

Surfactants are compounds that lower the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid...

 or a detergent

Detergent

A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions." In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water...

.

In household products, it may be found as an ingredient in fabric softeners, cosmetics, and hair conditioners in which it is added primarily for its antistatic effects. It is also used in organic synthesis

Organic synthesis

Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...

 as a phase transfer catalyst

Phase transfer catalyst

In chemistry, a phase transfer catalyst or PTC is a catalyst that facilitates the migration of a reactant from one phase into another phase where reaction occurs. Phase transfer catalysis is a special form of heterogeneous catalysis. Ionic reactants are often soluble in an aqueous phase but...

to increase reaction rates in a two-phase organic-water system.