What Is Trimethylamine?
Trimethylamine is a type of methylamine in which three hydrogens of ammonia are replaced by methyl groups.
It is classified as a specific malodorous substance and is a gaseous organic compound at room temperature with a very strong fish odor. It is also known as N,N-dimethylmethylamine.
Uses of Trimethylamine
Trimethylamine is used in many things, but it is generally not used in a gaseous state, but rather in an aqueous solution of about 30~40% dissolved in water. It is highly soluble in water and miscible with water in any ratio.
Specifically, it is used as a raw material for ion exchange resins, choline chloride, fiber oil, reverse soap, and pharmaceuticals. In addition, as a familiar example, it is originally present in processed low-fat fish products such as surumeika, nishin, and bora, and in raw fish products such as suzuki, etc. In Europe and North America, it is often used as a food additive to add flavor and flavor to various foods such as confectionery, meat products, frozen dairy products, soft drinks, etc. It is also used as a food additive to improve flavor and aroma of various foods.
Characteristics of Trimethylamine
The structural formula of trimethylamine is (CH3)3N. As can be seen from the structural formula, all the hydrogen of ammonia (NH3) is replaced by methyl groups. It has a molecular weight of 59.11, a density of 0.67 g/ml (0°C), a melting point of -117.1°C, and a boiling point of 2.9°C. It is a colorless, transparent gas at room temperature.
It is an extremely flammable and combustible gas, and has been shown to be harmful by inhalation and adhesion. Trimethylamine is characterized by its strong fish odor, but because it is an alkaline substance, it is known that it can be made odorless by reacting with acidic substances, and acidic deodorants are generally used for amine-based odors.
It is regulated by the Malodor Control Law and is registered as a specified malodorous substance. Specified malodorous substances are substances that cause unpleasant odors and may damage the living environment. The fact that only 22 substances are currently designated shows the strength of their odor.
Other Information on Trimethylamine
1. How Trimethylamine Is Produced
Trimethylamine is the most basic tertiary amine and is industrially produced by the reaction of methanol and ammonia in the presence of a dehydration catalyst.
1. Synthesis of Methylamine
First, a mixture of methanol and ammonia is passed through a dehydration catalyst such as alumina under pressure of 1.0~2.1 MPa at 450~500℃ to synthesize a mixture of three types of methylamines: monomethylamine, dimethylamine, and trimethylamine.
- Formation of Monomethylamine
CH3OH + NH3 → CH3NH2 + H2O - Generation of Dimethylamine
2CH3OH + NH3 → (CH3)2NH2 + 2H2O - Formation of Trimethylamine
3CH3OH + NH3 → (CH3)3NH2 + 3H2O
2. Separation of Trimethylamine by Dehydration and Distillation
After the product is distilled under pressure to separate the raw material methanol from the water produced, an azeotropic mixture of ammonia and trimethylamine is distilled out to separate monomethylamine and dimethylamine. Finally, trimethylamine is recovered by extractive distillation of the azeotropic mixture of ammonia and trimethylamine.
2. Safety of Trimethylamine
Trimethylamine is sold and used as a gas or as an aqueous solution, and has different safety and applicable regulations as well as properties.
In common with gases and aqueous solutions, both fall under the category of specified malodorous substances under the Malodor Prevention Act. In addition, when burned, they decompose to produce nitrous oxide, a toxic gas.
Other hazards include the following, so care must be taken when handling.
- Reacts violently with strong oxidizers, acids, and ethylene oxide.
- Corrosive to aluminum, zinc, and copper.
- Reacts with mercury to form shock-sensitive compounds.
- Reacts with nitrites and nitric acid to form extremely toxic nitrosamines