palmitic acid (another name - hexadecanoic) - a saturated monocarboxylic (fatty acid).The most common in nature.First a substance found in palm oil.Ethers and salts of this acid called palmitate.Numerous acid esters of the crystallinity and reminiscent of wax.It has the following chemical formula: CH3 (CH2) 14COOH.But its empirical formula is: C16H32O2.
Finding palmitic acid in nature
This substance has in the composition of glycerides most vegetable oils and animal fats.For example, soybean oil it contains 6.5% of palm oil - 38-47%, lard - 30%.In addition, hexadecanoic acid is a constituent of certain waxes in spermaceti sperm whale contains cetyl ether 90% hexadecanoic acid, beeswax and about 30% of its myristyl ether.In animals palmitic acid is the end product of the synthesis of fatty acids from acetyl-CoA.
in a hexadecanoic acid glyceride has a part of palm oil, vegetable fat in the North American and Chinese fruits and Croton sebiferum Stillinga sebifera, in the seeds of Rhus succedanea (in wax), in mirikonovom wax wild Myrica cerifera, in lanolin.In a free state palmitic acid is found in the seeds of paprika, in disputes Lycopodium and cadaveric wax (a major part).
physical properties of palmitic acid:
1. Condition (under standard conditions) - colorless crystals.
2. The molar mass is 256, 43 g / mol.
3. The density of 0.841 g / cc.
Thermal properties of palmitic acid:
1. The melting point is equal to 62,9 ° C.
2. The boiling point is equal to 105 ° C (at 0.01 mm Hg. Art.) And 167 ° C (at 1 mm Hg. Art.).
3. The flashpoint is 192 ° C.
4. The molar heat capacity (under normal conditions) is equal to 460 J / (mol · K).
What are the chemical properties of hexadecanoic acid?
1. Solubility in water is equal to 0.0007 (at 20 ° C).
2. Solubility in ethanol is 2600 (at 7,2 ° C).
3. Palmitic acid is moderately soluble in benzene and acetone.
Optical properties of palmitic acid:
1. The refractive index is 1.4219.
Preparation palmitic acid
This compound can be obtained in several ways: 1. By
fractional crystallization or retifikatsii mixtures of fatty acids which have been prepared by saponification of fats or oxidation of paraffins.
2. With heating cetyl alcohol with lime the sodium to 270 ° C (Dumas and Stas).
C16H33OH (cetyl alcohol) + O2 (oxygen) = C15H31COOH + H2O (water)
3. Upon melting elaidic (oleic acid) with sodium hydroxide:
CH3 (CH2) 7CH (oleic acid) = CH (CH2)7SOON + H2O (water) + O = C15H31COOH (palmitic acid formula) + CH3COOH (acetic acid)
4. The oxidation of nitric acid 2-oktodekanonom:
CH3 (CH2) 15-CO-CH3 + 3O (oxygen)= C15H31COOH (hexadecanoic acid) + CH3COOH (acetic acid)
5. Also, this material can be synthesized by methods of cyanide compounds from yodyura pentadecylic alcohol:
C15H31J + KCN (cyano compound) = KJ + C15H31-CN;
C15H31-CN (cyano compound) + 2H2O (water) = C15H31COOH (derived substance) + NH3
Where used palmitic acid?
1. The subject matter we have used in the manufacture of napalm, stearin (a special mixture with stearic acid), opaque cosmetics and various detergents, plasticizers and lubricants.The technique of this acid is used for the manufacture of suppositories.
2. Calcium palmitate is used as a component of compositions for protection against moisture and water (hydrophobic) of the skin, a variety of fabrics, wood, opaque cosmetics and makeup.
3. Also, use of sodium palmitate as component (thickener) of toilet and household soaps, emulsifier in cosmetics formulations.
4. methyl palmitate need for palmitic acid and some of its derivatives, hexadecanol.Also, this substance is used as a flavoring for the food.
5. Previously, lead salt hexadecanoic acid used for the production of pharmaceutical patches.
