Salicylic acid is a beta-hydroxy acid that is produced as a natural compound in plants. This compound is a small aromatic acid whose chemical name is monohydroxybenzoic acid. It is lipophilic and acts as a growth hormone in plants.
Salts and esters of this substance are known as salicylates, which are used in the pharmaceutical industry.
Physical and chemical properties:
Salicylic acid with the chemical formula C7H6O3 is a white to tan, odorless solid that dissolves slowly in water. This compound has low solubility in water. This substance produces irritating and smoky vapors with a very unpleasant odor when decomposed.
The most important physical and chemical properties of this compound can be summarized in the following table:
|Molar mass||138.122 g/mol|
|Appearance||Colorless to white crystals|
|Density||1.443 g/cm3 (20 °C)|
|Melting Point||158.6 °C (317.5 °F; 431.8 K)|
|Boiling point||200 °C (392 °F; 473 K) decomposes|
211 °C (412 °F; 484 K)
at 20 mmHg
|Solubility in water||1.24 g/L (0 °C)|
2.48 g/L (25 °C)
4.14 g/L (40 °C)
17.41 g/L (75 °C)
77.79 g/L (100 °C)
|Solubility||Soluble in ether, CCl4, benzene, propanol, acetone, ethanol, oil of turpentine, toluene|
|vapor pressure||10.93 mPa|
|Flashpoint||315 °F (157 °C)|
|Chemical Structure Depiction|
Formula and structure of Salicylic acid:
The structural formula of this compound is C6H4 (OH) COOH, which consists of a hydroxyl group attached to the benzene ring in the ortho position with respect to the carboxylic acid functional group. The carbon atoms in the benzene ring of this material are hybridized. Salicylic acid also forms an intramolecular hydrogen bond.
Synthesis of salicylic acid:
Salicylic acid is found in nature in salix, the bark of the willow tree. Some foods also contain salicylates; Such as almonds, apples, raisins, tomatoes, and spices such as thyme, cinnamon.
It is prepared from the amino acid by a biosynthesis method of phenylalanine.
Sodium salicylate is also obtained by the reaction of sodium phenolate with carbon dioxide at high temperature and pressure, which is synthesized by acidifying the product with sulfuric acid, salicylic acid.
Salicylic acid is also obtained by hydrolysis of aspirin or methyl salicylate with a base or strong acid.
Applications and uses of Salicylic acid:
This organic acid is widely used in the synthesis of organic matter and acts as a plant hormone.
This substance is widely used, especially in the pharmaceutical industry, and its most common use is in sedatives such as aspirin.
This acid is used as a food preservative, antibacterial and antiseptic.
Salicylic Acid is used as an additive in skincare products.
This natural compound is used in toothpaste as a disinfectant.
Applications of salicylic acid for the skin:
- Cleanses acne-prone skin and prevents it from recurring.
- Salicylic acid is a medicine to remove the outer layer of the skin and is used to treat acne and psoriasis.
- This compound when used as a cream or ointment; can minimize skin lesions such as warts by removing dead skin cells and strengthening normal cells.
Safety information of Salicylic acid:
Although the use of low-concentration salicylic acid products is usually considered safe, it can cause mild chemical burns at high concentrations.
These chemicals can also cause dangerous poisoning if swallowed.
Some people may experience allergic symptoms such as asthma and gastrointestinal disorders or diarrhea due to allergies to salicylates in these foods.
It may also enter the bloodstream if a large concentration of salicylic acid ointment is applied to the skin.
- Skin Contact: Immediately flush skin with water.
- Inhalation: move the person to the fresh air.
- Eye Contact: Rinse eyes with water for at least 15-20 minutes.
- Ingestion: Do not induce vomiting. Get medical aid immediately. Call a poison control center.
Packing and storage:
Store in a cool, dry, well-ventilated area away from incompatible substances. Keep containers tightly closed.