Glycerol

Glycerol . Also known as glycerin, the thick, colorless liquid that forms the basis of lipid composition . It is an alcoholic compound with three groups –OH ( hydroxyl )

Table of Contents

Summary

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1 Definition
2 History
3 Chemical structure of glycerin
4 Production
5 Generalities of glycerin
- 1 Other names
6 Applications
7 Health uses of glycerin
- 1 Personal care
- 2 Industrial manufacturing
- 3 Kitchen
- 4 Other uses
8 Stability and reactivity
9 Chemical hazards
10 Risk of inhalation
11 Sources

Definition

The word glycerol comes from the Greek Glykos , which means sweet. It has a viscous liquid appearance, it has no color , but it does have a characteristic odor, as well as a sweet taste. It is a hygroscopic compound , which means that it has the ability to yield or absorb moisture present in the surrounding environment. It is easily soluble in water , and decomposes in a boil , which enters at a temperature of 290ºC. It is a liquid compound if it is found at room temperature, (about 25ºC).

Glycerol is found in all types of oils, as well as in animal or vegetable fats, as long as these are associated with other fatty acids such as, for example, oleic or stearic .

Oils such as palm , or coconut oil , have a large amount of glycerol, around 70-80% fatty acids . Glycerol is present in a combined way in all animal and plant cells , forming part of the cell membranes as phospholipids .

The glycerol used worldwide, until 1949, came from the soap industries. Today, around 70% of its production is carried out in the United States , from glycerides , that is, from fats and oils, with the rest of the production being synthetic, as a by-product of propylene .

History

Around the year 600 (ane), the Phoenicians disclosed the alchemical knowledge of how to make soap , a few centuries later, it spread through Marseille , in the Gauls and in the Germanic towns . Previously this organic compound was not called “glycerin” or “glycerol,” because these names were created in the 20th century . In the fourteenth century during the reign of Charles I , the English crown monopolized the trade and manufacture of soap. In the following century, this knowledge was taken from alchemy for chemistry , a historical example would be that of the English chemist Claude Joseph Geoffroy ( 1741 ), who intensified his studies on the nature of fats, leading to the discovery of glycerin. Less than 40 years later, the Swedish chemist Carl Wilhelm Scheele was the first to isolate this compound in 1779 , heating a mixture of litharge (PbO) with olive oil . It was he who formalized the discovery that natural fats and oils contain glycerin.

Glycerol (3D model), showing the atoms and the solitary pair of electrons of each oxygen (in pink)

Chemical structure of glycerin

Glycerin: CH ₂ OH-CHOH-CH ₂ OH.

It is made up of three carbons , eight hydrogens and three oxygens . Its structure has simple bonds and is tetravalent .

Glycerin molecule

Production

All the propanetriol produced in the world until 1949 , came from the soap industry. Currently, 70% of glycerol production belongs to the United States, and comes from glycerides (natural fats and oils), and the rest from the production of synthetic glycerin (by-product of propylene), the production of fatty acids and esters of fatty acids (biodiesel).

It was produced by saponification of fats, as a by-product of soap making .

It can also be obtained as a by-product during the production of biodiesel by transesterification . Triglycerides react:

With an alcohol like ethanol.
With a catalyst to provide fatty acid ethyl esters.
Glycerol
1. Glycerol can also be produced in different ways from propylene .

Glycerin Overview

Other names

Glycerol
Glycerin
Propanetriol
Propane-1,2,3-triol 1,2,3-Trihydroxypropane
Semi- developed formula: HOCH ₂-CHOH-CH ₂ OH
Structural formula: C ₃H ₈ O ₃
Molecular formula n / a
Chemical family: Alcohols

Applications

The application of glycerol is very varied. Among its most frequent uses are:

The manufacture of cosmetic products , especially in the soap industry.
Within the medical area, it is used in the compositions of medications, as syrups, creams, etc.
At temperatures higher than 250ºC, in the heating baths.
In certain machinery it is used as a lubricant .
Antifreeze
Manufacture of different products, especially in the preparation of teas , coffees, and other vegetable extracts, as well as the production of refreshing beverages, where it is added as an additive to increase quality.
Manufacture of resins used as insulators.
It is an important component in varnishes, as well as in the paint and other finishing industry.

Uses of glycerin in health

Glycerol has been recognized as safe for human consumption since 1959. It can be used in various food products for different purposes. LD50 levels in rats are 12,600 mg / kg, in guinea pigs of 18,700 mg / kg. Several studies have shown that a large amount of glycerol (synthetic or natural) can be administered without the appearance of adverse health effects.

Glycerol is a precursor for the synthesis of triglycerides and phospholipids in the liver and adipose tissue . When the body uses stored fat for energy , glycerol and fatty acids are released into the bloodstream. Glycerol can be converted to glucose in the liver, the energy supply for cellular metabolism .

It also has a wide variety of applications, such as emulsifier , softening agent, plasticizer , stabilizing and wetting agent for pastry , ice cream and tobacco ; in body lotions, mouthwashes, and countless pharmaceutical and cosmetic preparations ; as a protective medium for freezing red blood cells , sperm , corneas and other tissues; in printing inks, paint resins; antifreeze mixtures; and as a raw material for nitroglycerin .

Personal care

For the skin it works as an emollient , moisturizer and lubricant .
For tired legs and feet.
Dry hands.

Industrial manufacturing

Preparation of plasticizers , lubricants , antifreezes and solvents .

Kitchen

Agent to dissolve dyes and flavorings .
Conservative agent in the preparation of preserves and jams.
In the manufacture of cakes, icings and candies.

Other uses

Cleaning agent and surface polish.
For tired legs and feet.
Preparation of various medications.
As a raw material in the manufacture of cosmetics.
As a lotion base.
In the printing industry.

Stability and reactivity

The substance decomposes on burning, in contact with hot surfaces or strong oxidants, under the influence of hygroscopic substances, producing acrolein. It reacts with strong oxidants, creating a risk of fire and explosion. Conditions to avoid: Avoid open flame. Materials to avoid: Strong oxidizers. Decomposition products: Carbon monoxide. Polymerization: Not applicable.

Chemical hazards

Inhalation risk

Evaporation at 20 ° C is negligible; however, an annoying concentration of airborne particles can be quickly achieved by spraying .