Paraffin, properties, brands, preparation and use
Paraffin, properties, brands, preparation and use.
Paraffin is a waxy mixture of saturated hydrocarbons (alkanes) are predominantly normal – linear structure, and composition from С18Н38 (octadecan) to С35Н72 (pentatriacontane).
Paraffin, specifications, characteristics
Chemical composition of paraffin
The physical properties of the paraffin. Density, melting point and boiling point of paraffin
Chemical properties of paraffin
The history of the discovery of paraffin
Paraffin wax features:
Paraffin is a waxy mixture of saturated hydrocarbons (alkanes) are predominantly normal – linear structure, and composition from С18Н38 (octadecan) to С35Н72 (pentatriacontane).
The name paraffin comes from the Latin parum (“barely”, “little”) + affinis (“kindred”), which means “lack of affinity” or “lack of reactivity” and refers to non-reactive nature of the paraffin.
Paraffin is mainly produced from oil. That’s why he got the second name – oil paraffin.
Chemical formula for paraffin is CnH2n+2, where n = from 18 to 35.
Depending on the degree of purification of paraffin wax is white in color (highly purified and the purified paraffin), or slightly yellow and from light yellow to light brown color (crude paraffin).
Paraffin does not dissolve water, but well soluble in a large quantity of organic solvents (in light gasoline, benzene, acetone, chloroform, ethyl ether, carbon disulphide, dichloroethane, in boiling ethyl alcohol, etc.), in oil (when heated) and mineral oil (when heated).
Waterproof. So, the paper impregnated with paraffin, frequently used for packaging products. Paperimpregnated with paraffin, waterproof and hydrophobic. Water is not only can’t penetrate it, but not even wets it. If water gets on this paper, it remains on the surface and can be easily erased with a cloth. From waxed cardboard used to produce packages for milk.
Combustible. Fire.
When heated above 90°C paraffin in the air begins to rapidly soar without boiling. Dense vapors of paraffin heated to 120-150°C in contact with air ignite.
Paraffin is a good electrical insulator.
Properties of the wax vary considerably depending on the content of light hydrocarbons, unsaturated compounds, resinous substances, various mechanical and other impurities. These impurities give the wax a yellow color, reduce its hardness, reduce the melting point.
Depending on what the proportions in the composition of the wax are heavy and light hydrocarbons , it may be in different aggregate States: liquid and solid.
Chemical composition of paraffin:
Paraffin is a mixture of saturated hydrocarbons (alkanes) structure from С18Н38 (octadecan) to С35Н72 (pentatriacontane), with predominantly normal – linear structure.
It also usually contains a number of isomers of saturated hydrocarbons (alkanes) having a branched structure, and aromatic hydrocarbons (arenes) and naphthenes (cycloalkanes, cycloparaffins).
The physical properties of the paraffin. Density, melting point and boiling point of paraffin:
Parameter name: | Value: |
Color | white |
The smell | odorless |
Taste | no taste |
Aggregate state (at 20 °C and atmospheric pressure of 1 ATM.) | solid, greasy to the touch |
The density of paraffin (at 15 °C and atmospheric pressure of 1 ATM.) kg/m3 | 0,880-0,915* |
The melting point of wax, °C | 45-65* |
The boiling point of wax, °C | 300-500* |
Flash point, °C | not below 160 |
The auto-ignition temperature, °C | not below 300** |
Specific heat of combustion, MJ/kg | 11,2 |
Coefficient of thermal conductivity (at 20 °C and atmospheric pressure of 1 ATM.) W/(m·K) | 0,267 |
Specific heat, j/(kg·K) | 2200 |
Specific resistance, Ohm·cm | 3·1018 |
Molar mass, g/mol | 300-450* |
* depending on the ratio of the concentrations of heavy and light hydrocarbons comprising wax;
** thick paraffin vapors have an auto-ignition temperature – 120-150 °C.
Chemical properties of paraffin:
Paraffins are inert to most chemicals. They are oxidized with nitric acid, oxygen in the air (at 140 °C and above) and certain other oxidizing agents with the formation of various fatty acids, the same fatty acids contained in the fats of vegetable and animal origin.
Reacts with chlorine with the formation of chlorinated paraffin wax.
The history of the discovery of paraffin:
Paraffin was first created in 1830 by German chemist Karl von Reichenbach, when he tried to develop tools for effective separation and purification of waxy substances found in oil. The wax represented a significant progress in the development of candle industry. Before it opened, candles were made from animal fat, oil and wax. These candles gave an unpleasant smell, very much smoked and was very expensive. The wax burned more pure and reliable, and was cheaper to produce than any other candle fuel. Its only drawback was the low melting point, causing the candles had a tendency to gutter before the burn. Soon, however, this disadvantage was eliminated by the addition of stearin (mixture of fatty acids from animal fats). Eventually the production of paraffin experienced a boom in the early twentieth century.
Brand paraffins:
GOST 23683-89 “Paraffin oil firm. Technical conditions” depending on the degree of purification and applications are installed the following brands of solid paraffin:
P-1 – highly purified paraffin, used in the manufacture of containers and packaging materials tough construction, adhesives and meltswith contact with food and used at elevated temperatures, in the manufacture of cosmetics and in the pharmaceutical industry;
P-2 – a highly purified paraffin, is used for coating and impregnation of flexible food packaging, preserving elasticity at low temperatures, as well as components alloys for coating wood, concrete, metal containersintended for storage of food products; in the production of various wax compositions, medical equipment and cosmetics;
B2, B3, B4, B5 – semi-paraffinsintended for use in a variety of industries, which places special demands on the purity of the products, in particular the grade B2 may be used for the manufacture of rubber products;
T-1, T-2, T-3, p – purified wax technical purposes, intended for use, as a rule, as raw materials in various industries:
T-1 – used for the manufacture of household chemicals, in particular of candles, and in other sectors of the economy;
T-2 is used in chemical, petrochemical industry and other sectors of the economy;
T-3 is used for impregnation and coating of technical grades of paper, cardboard, textiles, wood and metal surfaces; use in petrochemical industry;
C – used in the petrochemical industry for the production of synthetic fatty acids.
Receipt of paraffin:
Paraffin get:
from oil and petroleum products having a high content of paraffins,
– from side products of oil (slack waxes, of petrolatum),
The use of paraffin:
Paraffin wax is used:
– for the manufacture of candles and matches,
– the lubricant of the friction of the wooden parts (drawer runners, pencil cases, etc.), bike chain, lubrication for the sliding of cross-country skiing, downhill skiing and snowboarding,etc.,
– in cosmetics for the production of vaseline,
– as a food additive E905 in the food industry
in paraffin in medicine and cosmetology,
as an effective neutron moderator and generator of protons in nuclear physics and technology,
– in the manufacture of containers and packaging materials
– for the manufacture of rubber products,
for apprecilove fabrics,
– for manufacture of household chemical goods,
– for the production of synthetic fatty acids and α-olefins in the petrochemical industry,
– as insulating material,
– as a component of greases,
as additives to lubricating oils.
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