Paraffin wax

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Paraffin wax
Paraffin.jpg
Identifiers
ECHA InfoCard 100.029.375
E number E905 (glazing agents, ...)
UNII
Properties
CnH2n+2
AppearanceWhite solid [1]
Odor Odorless [1]
Density ~0.90 g/cm3 [1]
Melting point 37 °C (99 °F; 310 K)
Boiling point > 370 °C (698 °F)
~1 mg/L [1]
Hazards
Flash point 200–240 °C (392–464 °F; 473–513 K) [1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
Paraffin candle Candle black.jpg
Paraffin candle

Paraffin wax (or petroleum wax) is a soft colorless solid, derived from petroleum, coal or shale oil, that consists of a mixture of hydrocarbon molecules containing between twenty and forty carbon atoms. It is solid at room temperature and begins to melt above approximately 37 °C (99 °F), [2] its boiling point is >370 °C (698 °F). [3] Common applications for paraffin wax include lubrication, electrical insulation, and candles; [4] dyed paraffin wax can be made into crayons. It is distinct from kerosene and other petroleum products that are sometimes called paraffin. [5]

Petroleum Naturally occurring hydrocarbon liquid found underground

Petroleum is a naturally occurring, yellowish-black liquid found in geological formations beneath the Earth's surface. It is commonly refined into various types of fuels. Components of petroleum are separated using a technique called fractional distillation, i.e. separation of a liquid mixture into fractions differing in boiling point by means of distillation, typically using a fractionating column.

Coal A combustible sedimentary rock composed primarily of carbon

Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements; chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed if dead plant matter decays into peat and over millions of years the heat and pressure of deep burial converts the peat into coal. Vast deposits of coal originates in former wetlands—called coal forests—that covered much of the Earth's tropical land areas during the late Carboniferous (Pennsylvanian) and Permian times.

Oil shale Organic-rich fine-grained sedimentary rock containing kerogen

Oil shale is an organic-rich fine-grained sedimentary rock containing kerogen from which liquid hydrocarbons can be produced, called shale oil. Shale oil is a substitute for conventional crude oil; however, extracting shale oil from oil shale is more costly than the production of conventional crude oil both financially and in terms of its environmental impact. Deposits of oil shale occur around the world, including major deposits in the United States. A 2016 estimate of global deposits set the total world resources of oil shale equivalent of 6.05 trillion barrels of oil in place.

Contents

Un-dyed, unscented paraffin candles are odorless and bluish-white. Paraffin wax was first created by Carl Reichenbach in Germany in 1830, and marked a major advancement in candlemaking technology, as it burned more cleanly and reliably than tallow candles and was cheaper to produce. [6]

Tallow rendered form of beef or mutton fat

Tallow is a rendered form of beef or mutton fat, and is primarily made up of triglycerides. It is solid at room temperature. Unlike suet, tallow can be stored for extended periods without the need for refrigeration to prevent decomposition, provided it is kept in an airtight container to prevent oxidation.

In chemistry, paraffin is used synonymously with alkane , indicating hydrocarbons with the general formula CnH2n+2. The name is derived from Latin parum ("barely") + affinis, meaning "lacking affinity" or "lacking reactivity", referring to paraffin's unreactive nature. [7]

Alkane acyclic saturated hydrocarbon

In organic chemistry, an alkane, or paraffin (a historical name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single. Alkanes have the general chemical formula CnH2n+2. The alkanes range in complexity from the simplest case of methane (CH4), where n = 1 (sometimes called the parent molecule), to arbitrarily large and complex molecules, like pentacontane (C50H102) or 6-ethyl-2-methyl-5-(1-methylethyl) octane, an isomer of tetradecane (C14H30).

Latin Indo-European language of the Italic family

Latin is a classical language belonging to the Italic branch of the Indo-European languages. The Latin alphabet is derived from the Etruscan and Greek alphabets and ultimately from the Phoenician alphabet.

In chemistry and atomic physics, the electron affinity (Eea) of an atom or molecule is defined as the amount of energy released or spent when an electron is added to a neutral atom or molecule in the gaseous state to form a negative ion.

Properties

Paraffin wax is mostly found as a white, odorless, tasteless, waxy solid, with a typical melting point between about 46 and 68 °C (115 and 154 °F), [8] and a density of around 900 kg/m3. [9] It is insoluble in water, but soluble in ether, benzene, and certain esters. Paraffin is unaffected by most common chemical reagents but burns readily. [10] Its heat of combustion is 42 MJ/kg.

Wax class of chemical compounds that are plastic (malleable) near ambient temperatures.

Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C (104 °F), melting to give low viscosity liquids. Waxes are insoluble in water but soluble in organic, nonpolar solvents. Natural waxes of different types are produced by plants and animals and occur in petroleum.

Diethyl ether chemical compound

Diethyl ether, or simply ether, is an organic compound in the ether class with the formula (C
2
H
5
)
2
O
, sometimes abbreviated as Et
2
O
. It is a colorless, highly volatile flammable liquid. It is commonly used as a solvent in laboratories and as a starting fluid for some engines. It was formerly used as a general anesthetic, until non-flammable drugs were developed, such as halothane. It has been used as a recreational drug to cause intoxication.

Benzene Organic chemical compound

Benzene is an organic chemical compound with the chemical formula C6H6. The benzene molecule is composed of six carbon atoms joined in a ring with one hydrogen atom attached to each. As it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon.

The hydrocarbon C31H64 is a typical component of paraffin wax. Hentriacontane.svg
The hydrocarbon C31H64 is a typical component of paraffin wax.

Paraffin wax is an excellent electrical insulator, with a resistivity of between 1013 and 1017 ohm metre. [11] This is better than nearly all other materials except some plastics (notably Teflon). It is an effective neutron moderator and was used in James Chadwick's 1932 experiments to identify the neutron. [12] [13]

Polytetrafluoroethylene Polymer

Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. The well-known brand name of PTFE-based formulas is Teflon by Chemours. Chemours was a spin-off from DuPont, which originally discovered the compound in 1938. Another popular brand name of PTFE is Syncolon by Synco Chemical Corporation.

Neutron moderator medium that reduces the speed of fast neutrons, turning them into thermal neutrons that can sustain nuclear chain reactions; e.g. water, graphite, heavy water, beryllium

In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235 or a similar fissile nuclide.

James Chadwick English physicist

Sir James Chadwick, was a British physicist who was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron in 1932. In 1941, he wrote the final draft of the MAUD Report, which inspired the U.S. government to begin serious atomic bomb research efforts. He was the head of the British team that worked on the Manhattan Project during the Second World War. He was knighted in Britain in 1945 for his achievements in physics.

Paraffin wax is an excellent material for storing heat, with a specific heat capacity of 2.14–2.9 J g−1 K−1 (joules per gram kelvin) and a heat of fusion of 200–220 J g−1. [14] Paraffin wax phase-change cooling coupled with retractable radiators was used to cool the electronics of the Lunar Roving Vehicle during the manned missions to the Moon in the early 1970s. [15] Wax expands considerably when it melts and this allows its use in wax element thermostats for industrial, domestic and, particularly, automobile purposes. [16] [17]

The specific heat capacity of a substance is the heat capacity of a sample of the substance divided by the mass of the sample. Informally, it is the amount of energy that must be added, in the form of heat, to one unit of mass of the substance in order to cause an increase of one unit in its temperature. The SI unit of specific heat is joule per kelvin per kilogram, J/K/kg or J/(K kg). For example, at a temperature of 25 °C, the heat required to raise the temperature of 1 kg of water by 1 K is 4179.6 joules, meaning that the specific heat of water is 4.1796 kJ·kg−1·K−1.

Gram Unit of mass 1/1000th of a kilogram

The gram is a metric system unit of mass.

The kelvin is the base unit of temperature in the International System of Units (SI), having the unit symbol K. It is named after the Belfast-born, Glasgow University engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907).

History

Paraffin wax was first created in 1830 by the German chemist Karl von Reichenbach when he tried to develop the means to efficiently separate and refine the waxy substances naturally occurring in petroleum. Paraffin represented a major advance in the candlemaking industry, because it burned more cleanly and reliably, and was cheaper to manufacture than any other candle fuel. Paraffin wax initially suffered from a low melting point; however, this shortcoming was later remedied by the addition of harder stearic acid. The production of paraffin wax enjoyed a boom in the early 20th century as a result of the growth of the meatpacking and oil industries, which created paraffin and stearic acid as byproducts. [6]

Manufacturing

The feedstock for paraffin is slack wax, which is a mixture of oil and wax, a byproduct from the refining of lubricating oil.

The first step in making paraffin wax is to remove the oil (de-oiling or de-waxing) from the slack wax. The oil is separated by crystallization. Most commonly, the slack wax is heated, mixed with one or more solvents such as a ketone and then cooled. As it cools, wax crystallizes out of the solution, leaving only oil. This mixture is filtered into two streams: solid (wax plus some solvent) and liquid (oil and solvent). After the solvent is recovered by distillation, the resulting products are called "product wax" (or "press wax") and "foots oil". The lower the percentage of oil in the wax, the more refined it is considered (semi-refined versus fully refined). [18] The product wax may be further processed to remove colors and odors. The wax may finally be blended together to give certain desired properties such as melt point and penetration. Paraffin wax is sold in either liquid or solid form. [19] [20] [21]

Applications

In industrial applications, it is often useful to modify the crystal properties of the paraffin wax, typically by adding branching to the existing carbon backbone chain. The modification is usually done with additives, such as EVA copolymers, microcrystalline wax, or forms of polyethylene. The branched properties result in a modified paraffin with a higher viscosity, smaller crystalline structure, and modified functional properties. Pure paraffin wax is rarely used for carving original models for casting metal and other materials in the lost wax process, as it is relatively brittle at room temperature and presents the risks of chipping and breakage when worked. Soft and pliable waxes, like beeswax, may be preferred for such sculpture, but "investment casting waxes," often paraffin-based, are expressly formulated for the purpose.

In a pathology laboratory, paraffin wax is used to impregnate tissue prior to sectioning thin samples of tissue. Water is removed from the tissue through ascending strengths of alcohol (75% to absolute) and the tissue is cleared in an organic solvent such as xylene. The tissue is then placed in paraffin wax for a number of hours and then set in a mold with wax to cool and solidify; sections are then cut on a microtome.

Other uses

Occupational safety

People can be exposed to paraffin in the workplace by breathing it in, skin contact, and eye contact. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) for paraffin wax fume exposure of 2 mg/m3 over an 8-hour workday. [29]

See also

Related Research Articles

Beeswax chemical compound

Beeswax is a natural wax produced by honey bees of the genus Apis. The wax is formed into scales by eight wax-producing glands in the abdominal segments of worker bees, which discard it in or at the hive. The hive workers collect and use it to form cells for honey storage and larval and pupal protection within the beehive. Chemically, beeswax consists mainly of esters of fatty acids and various long-chain alcohols.

Candle solid block of wax with embedded wick

A candle is an ignitable wick embedded in wax, or another flammable solid substance such as tallow, that provides light, and in some cases, a fragrance. A candle can also provide heat, or be used as a method of keeping time. The candle can be used during the event of a power outage to provide light.

Oil refinery industrial process plant where crude oil is processed and refined into more useful products

An oil refinery or petroleum refinery is an industrial process plant where crude oil is transformed and refined into more useful products such as petroleum naphtha, gasoline, diesel fuel, asphalt base, heating oil, kerosene, liquefied petroleum gas, jet fuel and fuel oils. Petrochemicals feed stock like ethylene and propylene can also be produced directly by cracking crude oil without the need of using refined products of crude oil such as naphtha.

Varnish transparent, hard, protective finish or film used in painting

Varnish is a clear transparent hard protective finish or film. Varnish has little or no color and has no added pigment as opposed to paint or wood stain which contains pigment. However, some varnish products are marketed as a combined stain and varnish. Varnish is primarily used in wood finishing applications where the natural tones and grains in the wood are intended to be visible. It is applied over wood stains as a final step to achieve a film for gloss and protection. Varnish finishes are usually glossy but may be designed to produce satin or semi-gloss sheens by the addition of "flatting" agents.

Wax play

Wax play is a form of temperature play practiced in a BDSM context. The idea of wax play is to introduce a slight burning sensation to the skin.

Ski wax material applied to the bottom of snow runners, including skis, snowboards, and toboggans, to improve their coefficient of friction performance under varying snow conditions

Ski wax is a material applied to the bottom of snow runners, including skis, snowboards, and toboggans, to improve their coefficient of friction performance under varying snow conditions. The two main types of wax used on skis are glide waxes and grip waxes. They address kinetic friction—to be minimized with a glide wax—and static friction—to be achieved with a grip wax. Both types of wax are designed to be matched with the varying properties of snow, including crystal type and size, and moisture content of the snow surface, which vary with temperature and the temperature history of the snow. Glide wax is selected to minimize sliding friction for both alpine and cross-country skiing. Grip wax provides on-snow traction for cross-country skiers, as they stride forward using classic technique.

Buddy Burner

A Buddy Burner is a simple stove made from a can and part of a corrugated paper box. It is usually fueled by paraffin wax but other fuels, such as boiled butter, animal fat or diesel fuel, can be used. It is usually used for cooking but can also provide heat.

Petroleum product useful material derived from crude oil (petroleum)

Petroleum products are materials derived from crude oil (petroleum) as it is processed in oil refineries. Unlike petrochemicals, which are a collection of well-defined usually pure chemical compounds, petroleum products are complex mixtures. The majority of petroleum is converted to petroleum products, which includes several classes of fuels.

Ozokerite naturally occurring odoriferous mineral wax or paraffin

Ozokerite or ozocerite, archaically referred to as earthwax or earth wax, is a naturally occurring odoriferous mineral wax or paraffin found in many localities.

A glazing agent is a natural or synthetic substance that provides a waxy, homogeneous, coating to prevent water loss from a surface and provide other protection.

Microcrystalline waxes are a type of wax produced by de-oiling petrolatum, as part of the petroleum refining process. In contrast to the more familiar paraffin wax which contains mostly unbranched alkanes, microcrystalline wax contains a higher percentage of isoparaffinic (branched) hydrocarbons and naphthenic hydrocarbons. It is characterized by the fineness of its crystals in contrast to the larger crystal of paraffin wax. It consists of high molecular weight saturated aliphatic hydrocarbons. It is generally darker, more viscous, denser, tackier and more elastic than paraffin waxes, and has a higher molecular weight and melting point. The elastic and adhesive characteristics of microcrystalline waxes are related to the non-straight chain components which they contain. Typical microcrystalline wax crystal structure is small and thin, making them more flexible than paraffin wax. It is commonly used in cosmetic formulations.

Hot-melt adhesive solvent-free and at room temperature more or less solid products which are applied to the adhesive surface when hot

Hot melt adhesive (HMA), also known as hot glue, is a form of thermoplastic adhesive that is commonly sold as solid cylindrical sticks of various diameters designed to be applied using a hot glue gun. The gun uses a continuous-duty heating element to melt the plastic glue, which the user pushes through the gun either with a mechanical trigger mechanism on the gun, or with direct finger pressure. The glue squeezed out of the heated nozzle is initially hot enough to burn and even blister skin. The glue is tacky when hot, and solidifies in a few seconds to one minute. Hot melt adhesives can also be applied by dipping or spraying, and are popular with hobbyists and crafters both for affixing and as an inexpensive alternative to resin casting.

History of candle making aspect of history

Candle making was developed independently in many places throughout history.

Higher alkanes are alkanes having nine or more carbon atoms. Nonane is the lightest alkane to have a flash point above 25 °C, and is not classified as dangerously flammable.

Soy candle

Soy candles are candles made from soy wax, which is a processed form of soybean oil. They are usually container candles, because soy wax typically has a lower melting point than traditional waxes, but can also be made into pillar candles if certain additives are mixed into the soy wax.

Renaissance Wax

Renaissance Wax is a brand of microcrystalline wax polish used in antique restoration and museum conservation. Most safely used to polish and conserve metal objects, it is also used on gemstones and such organic materials wood, ivory, and tortoiseshell. The product is sometimes used by reenactors to protect armor and weapons. Waxes are more protective and longer-lasting than oil, especially for swords and helmets that are frequently touched by human hands. It has recently been introduced in the world of guitar building, as a finish that protects and gives colour to the wood.

A melting tank is a tank used by manufacturing companies to manufacture a variety of products.

A wax emulsion is a stable mixture of one or more waxes in water. Waxes and water are normally immiscible but can be brought together stably by the use of surfactants and a clever preparation process. Strictly speaking a wax emulsion should be called a wax dispersion since the wax is solid at room temperature. However, because the preparation takes place above the melting point of the wax, the actual process is called emulsification, hence the name wax emulsion. In praxis, wax dispersion is used for solvent based systems.

References

  1. 1 2 3 4 5 Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  2. Freund, Mihály; Mózes, Gyula (1982). Paraffin products: properties, technologies, applications. Translated by Jakab, E. Amsterdam, The Netherlands: Elsevier. p. 121. ISBN   978-0-444-99712-8.
  3. "Paraffin Wax". Chemical book. Retrieved 25 October 2013.
  4. Raw materials and candles production processes, AECM
  5. Charles B. Willingham; William J. Taylor; Joan M. Pignocco; Frederick D. Rossini. "Research Paper RP1670 | Vapor Pressures and Boiling Points of Some Paraffin, Alkylcycopentane, Alkylcyclohexane and Alkylbenzene Hydrocarbons" (PDF). National Institute of Standards and Technology . US Department of Commerce National Bureau of Standards.
  6. 1 2 "History of Candles". National Candle Association. Retrieved 25 February 2016.
  7. "Paraffin, n". Oxford English Dictionary. Oxford, England: Oxford University Press. March 2009.
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  9. Kaye, George William Clarkson; Laby,Thomas Howell. "Mechanical properties of materials". Kaye and Laby Tables of Physical and Chemical Constants. National Physical Laboratory . Retrieved 25 October 2013.
  10. Seager, Spencer L.; Slabaugh, Michael (19 January 2010). "Alkane reactions". Chemistry for Today: General, Organic, and Biochemistry. Belmont, California: Cengage. p. 364. ISBN   978-0-538-73332-8.
  11. "Electrical insulating materials". Kaye and Laby Tables of Physical and Chemical Constants. National Physical Laboratory. 1995. Retrieved 25 October 2013.
  12. "Attenuation of fast neutrons: neutron moderation and diffusion". Kaye and Laby Tables of Physical and Chemical Constants. National Physical Laboratory. Retrieved 25 October 2013.
  13. Rhodes, Richard (1981). The Making of the Atomic Bomb. New York: Simon and Schuster. p. 163. ISBN   978-0-671-44133-3.
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  15. Dean, W. G.; Karu, Z. S. (February 1993). "Space Station thermal storage/refrigeration system research and development". Final Report Lockheed Missiles and Space Co. Bibcode:1993lock.rept.....D.
  16. Wax-pellet thermostat United States Patent 4948043
  17. 1 2 Bodén, Roger. "Paraffin Microactuator" (PDF). Materials Science Sensors and Actuators. University of Uppsala. Archived from the original (PDF) on 8 February 2012. Retrieved 25 October 2013.
  18. "Paraffin Wax (Fully Refined)". Barasat Wax Refiner. Retrieved 21 December 2012.
  19. "Wax Refining". The International Group, Inc. Retrieved 21 December 2012.
  20. "Paraffin wax". Bitumen Engineering. Retrieved 21 December 2012.
  21. "Manufacturing Process". Barasat Wax Refiner. Retrieved 21 December 2012.
  22. Staff (Fall 2004). "Rocket motor uses common household product for fuel" (PDF). OASIS Ocean Air Space Industry Site. 1 (3): 6. Retrieved 28 November 2008.
  23. Tabor, Abigail (18 April 2017). "From Pedicures to the Peregrine Rocket, Paraffin Wax Proves Its Worth". NASA.gov. Retrieved 26 March 2019.
  24. "Paraffin, microcrystalline, petrolatum, wax blends - Microcrystalline Wax". igiwax.com. Retrieved 29 April 2017.
  25. ( Freund & Mózes 1982 , p. 272)
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  27. "Instrument Information". NASA . 2007. Retrieved 24 January 2017.
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