Propionic acid, also known as primary oleic acid, is a short chain saturated fatty acid with the chemical formula CH3CH2COOH and molecular weight of 74.08. [9] Propionic acid belongs to weak electrolyte (Ka=1.34 × 10-5), its aqueous solution is weakly acidic, but highly corrosive, and the steam is irritating to the skin and respiratory tract. Under normal temperature and pressure, propionic acid is a colorless, clear, oily liquid with an unpleasant rancidity and pungent smell. It is miscible with water, ethanol, chloroform and ether.
Propionic acid is mainly used as food preservative and mildew inhibitor, as well as as inhibitor of medium viscosity substances such as beer, nitrocellulose solvent and plasticizer, and it can also be used in the preparation of nickel plating solution, food flavor, medicine, pesticide, mildew inhibitor, etc.
Application field:
1. Used as organic reagent, esterification agent and plasticizer. Because propionic acid can dissolve most organic substances, propionic acid is also a commonly used organic solvent.
2. Propionic acid can be used in some pickling and polishing solutions, as a buffer in weak acid solutions (such as zinc plating and chemical nickel plating), as an additive in semi bright nickel plating electrolyte, and in zinc and cadmium passivation solutions to improve the adhesion of the passivation film, and is often used to adjust the pH of weak acid plating solutions.
3. Synthesis of derivatives of propionic acid. Propionic acid can be used to produce propionate, such as sodium, aluminum, zinc, cobalt and other metal propionate. Propionic acid is widely used as catalyst, auxiliary agent in fabric dyeing and leather tanning industry; In addition, sodium propionate, calcium propionate and propionic acid can also be used as food preservation, and can also provide calcium, sodium, potassium and other trace elements for food or feed. If 0.5% (m/v) calcium propionate is added to soy sauce, it can be kept for 90 days in summer without mildew.
In addition, propionic acid can also be used to synthesize its esters and derived intermediates. Propionate esters can be widely used as pesticide herbicides, resin modifiers, sterilization agents, cigarette filter tip plasticizers, etc. For example, benzyl propionate is an additive for edible essence and cosmetics, isoamyl propionate and ethyl propionate can be used as fruit flavors such as apple, pineapple, pear, strawberry, and also as artificial flower essential oil. Propionate esters formed from lower alcohols are excellent solvents, widely used in the paint industry [10] Propionic acid can also be used to synthesize cellulose propionate. Cellulose acetate propionate produced from propionic acid can be used in automobile parts, TV sets, etc.
4. Determination of aromatic diamines, gas chromatography analysis standard, can also be used to inhibit the growth of mold in insect cell culture.
5. As a food preservative, propionic acid can prevent food from rotting and deteriorating due to microbial action, and extend the storage time, especially for the preservation and storage of bread and pastries. Propionic acid can also be used to preserve poultry feed. If 0.5% propionic acid is added to green feed, it can keep it from mildew for 6 months, prevent protein decomposition and improve digestibility. [8] 60% of propionic acid produced in China is used as food preservative and grain preservation.
6. As an intermediate of spices, propionic acid is used with acetic acid in butter, milk, and yogurt. It can be used as the raw material of synthetic spices to give spices a natural sour taste
7. It can be used as pharmaceutical intermediates, such as propionic anhydride as propionylation agent for medicine, and as antibiotic drugs, such as keratosamycin propionate. It can also be made into a dispersant containing 15% calcium propionate and an ointment or solution containing 12.3% sodium propionate, which can treat diseases caused by skin parasitic mold, and can also be used as an intermediate of medicine.
Storage method
Store in a cool and ventilated warehouse. Keep away from kindling and heat source. The warehouse temperature should not exceed 30 ℃. Keep container sealed. It shall be stored separately from oxidants, reducing agents and alkalis, and shall not be mixed. Explosion proof lighting and ventilation facilities shall be adopted. It is prohibited to use mechanical equipment and tools that are easy to generate sparks. The storage area shall be equipped with leakage emergency treatment equipment and appropriate materials.
Transportation method
The railway transportation shall be carried out in strict accordance with the dangerous goods loading table in the Dangerous Goods Transportation Rules of the Ministry of Railways. The package shall be complete and the loading shall be stable during shipment. During transportation, containers shall be free from leakage, collapse, falling and damage. The tank (tank) truck used for transportation shall be equipped with grounding chain, and hole partition can be set in the tank to reduce static electricity generated by vibration. It is strictly prohibited to mix with oxidants, reducing agents, alkalis, edible chemicals, etc. Road transportation shall be carried out according to the specified route, and shall not stay in residential areas and densely populated areas.