The Uses of carboxylic acids Are so extensive that they can be divided into several industries, such as pharmaceuticals (active for the manufacture of vitamin C-based medicines) or food (production of soft drinks, manufacture of additives), among others.
Carboxylic acids are essentially organic acids having a carboxyl group among their components, attached to an alkyl or aryl group.
They are represented in a chemical formula as follows: COOH, and its denomination is due to the conjugation or combination of carbonyl (C = O) and hydroxyl.
If the carbon chain has only one carboxyl group, the acids are called monocarboxylic acids or fatty acids, whereas if it has two carboxyl groups, the acids are called dicarboxylic acids.
They are also referred to as organic acids, and are often"weak"acids, with only 1% of the RCOOH molecules dissociated into ions (when it is at room temperature and in an aqueous solution).
They are weaker acids than mineral acids such as hydrochloric acid or sulfuric acid. However, its acidity is higher than that of alcohols.
These are polar substances, which come to form hydrogen bonds with each other or with the molecules of another substance.
What are the main uses of carboxylic acids?
Carboxylic acids occur naturally in fats, acidic dairy and citrus fruits, and among their most important uses are:
Food industry
1- Additives.
2- Preservatives (Sorbic acid and benzoic acid).
3- Alkalinity regulator of many products.
4- Production of soft drinks.
5- Antimicrobial agents against the action of antioxidants. In this case, the tendency is for liquid antimicrobials to allow bioavailability.
6- Main ingredient of common vinegar (acetic acid).
7- Acidulant in carbonated beverages and foods (Citric acid and lactic acid).
8- Helper in the maturation of Swiss cheese (propionic acid).
9- Elaboration of cheese, sauerkraut, fermented cabbage and soft drinks (lactic acid).
Pharmaceutical industry
10- Antipyretic and analgesic (acetylsalicylic acid).
11- Active in the process of synthesis of aromas, in some drugs (butyric or butanoic acid).
12- Antimycotic (benzoic acid combined with salicylic acid).
13- Active for the manufacture of medicines based on vitamin C (ascorbic acid).
14- Fungicide (Caprylic acid).
15- Manufacture of some laxatives (Hydroxybutanedioic acid).
Other Industries
16- Manufacture of plastics and lubricants (Sorbic acid).
17- Manufacture of varnishes, resins and transparent adhesives (acrylic acid).
18- Manufacture of paints and varnishes (Linoleic acid).
19- Manufacture of soaps, detergents, shampoos, cosmetics and metal cleaning products (Oleic acid).
20- Manufacture of toothpaste (Salicylic acid).
21- Production of rayon acetate, photographic films and solvents for paints (acetic acid).
22- Production of dyes and tanned (Methanoic acid).
23- Manufacture of lubricating oils, impermeable materials and paint drying (palmitic acid).
24- Manufacture of rubber (Acetic acid).
25- Elaboration of rubber and electroplating.
26- Solvent.
27- Production of perfumes (benzoic acid).
28- Manufacture of plasticizers and resins (phthalic acid).
29- Elaboration of polyester (terephthalic acid).
30- Preparation of paraffin candles (Stearic acid).
In agriculture they are also often used to improve the quality of fruit crops, increasing the quantity and weight of the fruits in some plants, as well as their appearance and their post-harvest duration.
Carboxylic acids are very present in the advances of experimental and biochemical chemistry, especially those related to the fermentation necessary for the production of several products of commercial interest (antibiotics, organic solvents and vitamins, among others).
Properties of carboxylic acids
Some properties of these chemicals are:
Solubility
The first four aliphatic monocarboxylic acids are liquid and water soluble.
This property decreases if the number of carbon atoms increases, so from the dodecanoic acid, they begin to be insoluble in water.
Boiling point
The boiling point of these substances is elevated by the presence of a double hydrogen bond between their components.
Melting point
This is a property that varies according to the number of carbons since these affect the association between the molecules.
From the 6 carbons, an irregular elevation at the melting point begins.
References
- Abreu Payrol, Juan, & otros (2001). Carboxylic acids of the fruit of Bromelia pinguin L. (mouse pineapple) by HPLC. Revista Cubana de Farmacia, 35 (2), 122-125. Retrieved from: scielo.sld.cu.
- Binod, Shrestha (2010). Uses of carboxylic acid. Retrieved from: chem-guide.blogspot.com.
- Netto, Rita (2011). Organic acids present in everyday life. Recovered from: alimentacion.enfasis.com.
- Main carboxylic acids and their applications. Recovered from: quiminet.com.
- Rank, J. (s / f). Carboxylic Acids - Industrial Importance - Fatty, Esters, Organic, and Soluble. Retrieved from: science.jrank.org.
- Requena, L. (2001). Let's Study Organic Chemistry. Héctor A. García Educational Foundation. Recovered from: salonhogar.net.
- Román Moreno, Luís F. (1998). Evaluation of carboxylic acids and calcium nitrate to increase quality, quantity and shelf life in three types of melon in the Revista Terra Latinoamericana 1998 16 (1). Retrieved from: redalyc.org.