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{{short description|Soft colorless solid derived from petroleum, coal or shale oil}}
{{short description|Soft colorless solid derived from petroleum, coal or shale oil}}
{{about|the wax|the fuel|kerosene}}
{{Use dmy dates|date=March 2019}}
{{Use dmy dates|date=March 2019}}
{{Chembox
{{Chembox
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| Section3 = {{Chembox Hazards
| Section3 = {{Chembox Hazards
| MainHazards =
| MainHazards =
| FlashPtC = 200-240
| FlashPtC = 200–240
| FlashPt_ref = <ref name=GESTIS/>
| FlashPt_ref = <ref name=GESTIS/>
| AutoignitionPt =
| AutoignitionPt =
}}
}}
}}
}}

[[File:Candle black.jpg|thumb|100px|Paraffin candle]]
[[File:Candle black.jpg|thumb|100px|Paraffin candle]]

'''Paraffin wax''' (or '''petroleum wax''') is a soft colorless solid derived from [[petroleum]], [[coal]], or [[oil shale]] that consists of a mixture of [[hydrocarbon]] molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and [[melting point|begins to melt]] above approximately {{convert|37|°C|°F}},<ref>{{cite book|last1=Freund |first1=Mihály |last2=Mózes |first2=Gyula|translator=Jakab, E.|title=Paraffin products: properties, technologies, applications|year=1982|publisher=Elsevier|location=Amsterdam, The Netherlands|isbn=978-0-444-99712-8|page=121}}</ref> and its boiling point is above {{convert|370|°C|°F}}.<ref>{{cite web |title=Paraffin Wax |work=Chemical book |url=http://www.chemicalbook.com/ProductMSDSDetailCB2854418_EN.htm |access-date=25 October 2013}}</ref> Common applications for paraffin wax include [[lubrication]], [[electrical insulation]], and [[candles]];<ref>[http://europecandles.org/pages/uk/an-everlasting-history/raw-materials-and-candles-production-processes.php Raw materials and candles production processes] {{Webarchive|url=https://web.archive.org/web/20200321103525/https://europecandles.org/raw-materials-and-candles-production-processes |date=21 March 2020 }}, AECM</ref> dyed paraffin wax can be made into [[crayon]]s. It is distinct from [[kerosene]] and other petroleum products that are sometimes called paraffin.<ref>{{cite web|url=https://nvlpubs.nist.gov/nistpubs/jres/35/jresv35n3p219_A1b.pdf|title=Research Paper RP1670 {{!}} Vapor Pressures and Boiling Points of Some Paraffin, Alkylcycopentane, Alkylcyclohexane and Alkylbenzene Hydrocarbons|website=[[National Institute of Standards and Technology]]|publisher=[[US Department of Commerce]] [[National Bureau of Standards]]|author1=Charles B. Willingham|author2=William J. Taylor|author3=Joan M. Pignocco|author4=Frederick D. Rossini}}</ref>
'''Paraffin wax''' (or '''petroleum wax''') is a soft colorless solid derived from [[petroleum]], [[coal]], or [[oil shale]] that consists of a mixture of [[hydrocarbon]] molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and [[melting point|begins to melt]] above approximately {{convert|37|°C|°F}},<ref name="PF">{{cite book |last1=Freund |first1=Mihály |last2=Mózes |first2=Gyula |translator=Jakab, E. |title=Paraffin products: properties, technologies, applications |year=1982 |publisher=Elsevier |location=Amsterdam, the Netherlands |isbn=978-0-444-99712-8 |page=121 }}</ref> and its boiling point is above {{convert|370|°C|°F}}.<ref name="PF"/> Common applications for paraffin wax include [[lubrication]], [[electrical insulation]], and [[candles]];<ref>[http://europecandles.org/pages/uk/an-everlasting-history/raw-materials-and-candles-production-processes.php Raw materials and candles production processes] {{Webarchive|url=https://web.archive.org/web/20200321103525/https://europecandles.org/raw-materials-and-candles-production-processes |date=21 March 2020 }}, AECM</ref> dyed paraffin wax can be made into [[crayon]]s.


Un-dyed, unscented paraffin candles are odorless and bluish-white. Paraffin wax was first created by [[Carl Reichenbach#Scientific contributions|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.<ref name="auto">{{cite web|title=History of Candles|url=http://candles.org/history/|website=National Candle Association|access-date=25 February 2016}}</ref>
Un-dyed, unscented paraffin candles are odorless and bluish-white. Paraffin wax was first created by [[Carl Reichenbach#Scientific contributions|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.<ref name="auto">{{cite web|title=History of Candles|url=http://candles.org/history/|website=National Candle Association|access-date=25 February 2016}}</ref>
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== Properties ==
== Properties ==
Paraffin [[wax]] is mostly found as a white, odorless, tasteless, waxy solid, with a typical melting point between about {{convert|46|and|68|°C|°F}},<ref>{{cite book|last=Nasser|first=William E|editor=McKetta, John J|title=Encyclopedia of Chemical Processing and Design|volume=67|year=1999|publisher=Marcel Dekker|location=New York|isbn=978-0-8247-2618-8|page=17|chapter=Waxes, Natural and Synthetic}} This can vary widely, even outside the quoted range, according to such factors as oil content and crystalline structure.</ref> and a density of around 900&nbsp;kg/m<sup>3</sup>.<ref name=kayelabymech>{{cite web
Paraffin [[wax]] is mostly found as a white, odorless, flavourless, waxy solid, with a typical melting point between about {{convert|46|and|68|°C|°F}},<ref>{{cite book|last=Nasser|first=William E|editor=McKetta, John J|title=Encyclopedia of Chemical Processing and Design|volume=67|year=1999|publisher=Marcel Dekker|location=New York|isbn=978-0-8247-2618-8|page=17|chapter=Waxes, Natural and Synthetic}} This can vary widely, even outside the quoted range, according to such factors as oil content and crystalline structure.</ref> and a density of around 900&nbsp;kg/m<sup>3</sup>.<ref name=kayelabymech>{{cite web
| last =Kaye
| last =Kaye
| first =George William Clarkson
| first =George William Clarkson
| author2 =Laby,Thomas Howell
| author2 =Laby, Thomas Howell
| author-link2 =T. H. Laby
| author-link2 =T. H. Laby
| title =Mechanical properties of materials
| title =Mechanical properties of materials
Line 55: Line 56:
| url-status =dead
| url-status =dead
}}</ref> It is insoluble in water, but soluble in [[diethyl ether|ether]], [[benzene]], and certain [[ester]]s. Paraffin is unaffected by most common chemical [[reagent]]s but [[combustion|burns]] readily.<ref>{{cite book|last1=Seager|first1=Spencer L.|last2=Slabaugh|first2=Michael|title=Chemistry for Today: General, Organic, and Biochemistry|publisher=Cengage|location=Belmont, California|isbn=978-0-538-73332-8|page=364|chapter=Alkane reactions|date=19 January 2010}}</ref> Its heat of combustion is 42 MJ/kg.<ref>{{Cite journal|last=Wiener|first=Harry|date=January 1947|title=Structural Determination of Paraffin Boiling Points|url=https://pubs.acs.org/doi/pdf/10.1021/ja01193a005|journal=Journal of the American Chemical Society|volume=69|issue=1|pages=17–20|doi=10.1021/ja01193a005|pmid=20291038|issn=0002-7863}}</ref>
}}</ref> It is insoluble in water, but soluble in [[diethyl ether|ether]], [[benzene]], and certain [[ester]]s. Paraffin is unaffected by most common chemical [[reagent]]s but [[combustion|burns]] readily.<ref>{{cite book|last1=Seager|first1=Spencer L.|last2=Slabaugh|first2=Michael|title=Chemistry for Today: General, Organic, and Biochemistry|publisher=Cengage|location=Belmont, California|isbn=978-0-538-73332-8|page=364|chapter=Alkane reactions|date=19 January 2010}}</ref> Its heat of combustion is 42 MJ/kg.<ref>{{Cite journal|last=Wiener|first=Harry|date=January 1947|title=Structural Determination of Paraffin Boiling Points|url=https://pubs.acs.org/doi/pdf/10.1021/ja01193a005|journal=Journal of the American Chemical Society|volume=69|issue=1|pages=17–20|doi=10.1021/ja01193a005|pmid=20291038|issn=0002-7863}}</ref>
:[[Image:Hentriacontane.svg|270px|thumb|right|The hydrocarbon [[Hentriacontane|C<sub>31</sub>H<sub>64</sub>]] is a typical component of paraffin wax.]]
: [[Image:Hentriacontane.svg|270px|thumb|right|The hydrocarbon [[Hentriacontane|C<sub>31</sub>H<sub>64</sub>]] is a typical component of paraffin wax.]]


Paraffin wax is an excellent [[electrical insulator]], with a [[resistivity]] of between 10<sup>13</sup> and 10<sup>17</sup> [[Resistivity|ohm metre]].<ref name =kayelabyelec>{{cite web
Paraffin wax is an excellent [[electrical insulator]], with a [[resistivity]] of between 10<sup>13</sup> and 10<sup>17</sup> [[Resistivity|ohm-metre]].<ref name =kayelabyelec>{{cite web
| title =Electrical insulating materials
| title =Electrical insulating materials
| work =Kaye and Laby Tables of Physical and Chemical Constants
| work =Kaye and Laby Tables of Physical and Chemical Constants
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| archive-date =27 September 2007
| archive-date =27 September 2007
| url-status =dead
| url-status =dead
}}</ref> This is better than nearly all other materials except some [[plastics]] (notably [[polytetrafluoroethylene|Teflon]]). It is an effective [[neutron moderator]] and was used in [[James Chadwick]]'s 1932 experiments to identify the neutron.<ref>{{cite web
}}</ref> This is better than nearly all other materials except some [[plastics]] (notably [[polytetrafluoroethylene|PTFE]]). It is an effective [[neutron moderator]] and was used in [[James Chadwick]]'s 1932 experiments to identify the neutron.<ref>{{cite web
| title =Attenuation of fast neutrons: neutron moderation and diffusion
| title =Attenuation of fast neutrons: neutron moderation and diffusion
| work =Kaye and Laby Tables of Physical and Chemical Constants
| work =Kaye and Laby Tables of Physical and Chemical Constants
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| isbn =978-0-671-44133-3}}</ref>
| isbn =978-0-671-44133-3}}</ref>


Paraffin wax is an excellent material for [[Phase change material|storing heat]], with a [[specific heat capacity]] of 2.14–2.9&nbsp;J&nbsp;g<sup>−1</sup>&nbsp;K<sup>−1</sup> ([[joules]] per [[gram]] [[kelvin]]) and a [[Enthalpy of fusion|heat of fusion]] of 200–220&nbsp;J&nbsp;g<sup>−1</sup>.<ref>{{cite encyclopedia| title =Specific Heat Capacity| encyclopedia =Diracdelta.co.uk Science and Engineering Encyclopedia| publisher =Dirac Delta Consultants Ltd, Warwick, England| url =http://www.diracdelta.co.uk/science/source/s/p/specific%20heat%20capacity/source.html| url-status =dead| access-date=25 October 2013| archive-url =https://web.archive.org/web/20070804192935/http://www.diracdelta.co.uk/science/source/s/p/specific%20heat%20capacity/source.html| archive-date =4 August 2007| df =dmy-all}}</ref> Paraffin wax phase-change cooling coupled with retractable radiators was used to cool the electronics of the [[Lunar Roving Vehicle]] during the crewed missions to the Moon in the early 1970s.<ref>{{cite journal |title=Space Station thermal storage/refrigeration system research and development |last1=Dean |first1=W. G. |last2=Karu |first2=Z. S. |date=February 1993 |bibcode=1993lock.rept.....D |journal=Final Report Lockheed Missiles and Space Co.}}</ref> Wax expands considerably when it melts and this allows its use in [[wax thermostatic element|wax element]] [[thermostat]]s for industrial, domestic and, particularly, automobile purposes.<ref>[http://www.freepatentsonline.com/4948043.html Wax-pellet thermostat] United States Patent 4948043</ref><ref name="rogerboden">{{cite web|url=http://hermes.material.uu.se/~klas/Paraffin_lab_eng.pdf|title=Paraffin Microactuator|last=Bodén|first=Roger|work=Materials Science Sensors and Actuators|publisher=University of Uppsala|archive-url=https://web.archive.org/web/20120208100013/http://hermes.material.uu.se/~klas/Paraffin_lab_eng.pdf|archive-date=8 February 2012|url-status=dead|access-date=25 October 2013}}</ref>
Paraffin wax is an excellent material for [[Phase change material|storing heat]], with a [[specific heat capacity]] of 2.14–2.9&nbsp;J⋅g<sup>−1</sup>⋅K<sup>−1</sup> ([[joules]] per [[gram]] per [[kelvin]]) and a [[Enthalpy of fusion|heat of fusion]] of 200–220&nbsp;J⋅g<sup>−1</sup>.<ref>{{cite encyclopedia| title =Specific Heat Capacity| encyclopedia =Diracdelta.co.uk Science and Engineering Encyclopedia| publisher =Dirac Delta Consultants Ltd, Warwick, England| url =http://www.diracdelta.co.uk/science/source/s/p/specific%20heat%20capacity/source.html| url-status =dead| access-date=25 October 2013| archive-url =https://web.archive.org/web/20070804192935/http://www.diracdelta.co.uk/science/source/s/p/specific%20heat%20capacity/source.html| archive-date =4 August 2007| df =dmy-all}}</ref> Paraffin wax phase-change cooling coupled with retractable radiators was used to cool the electronics of the [[Lunar Roving Vehicle]] during the crewed missions to the Moon in the early 1970s.<ref>{{cite journal |title=Space Station thermal storage/refrigeration system research and development |last1=Dean |first1=W. G. |last2=Karu |first2=Z. S. |date=February 1993 |journal=Final Report Lockheed Missiles and Space Co.}}</ref> Wax expands considerably when it melts and so is used in [[wax thermostatic element|wax element]] [[thermostat]]s for industrial, domestic and, particularly, automobile purposes.<ref>[http://www.freepatentsonline.com/4948043.html Wax-pellet thermostat] United States Patent 4948043</ref><ref name="rogerboden">{{cite web|url=http://hermes.material.uu.se/~klas/Paraffin_lab_eng.pdf|title=Paraffin Microactuator|last=Bodén|first=Roger|work=Materials Science Sensors and Actuators|publisher=University of Uppsala|archive-url=https://web.archive.org/web/20120208100013/http://hermes.material.uu.se/~klas/Paraffin_lab_eng.pdf|archive-date=8 February 2012|url-status=dead|access-date=25 October 2013}}</ref>

If pure paraffin wax melted to the approximate flash point in a half open glass vessel which is then suddenly cooled down, then its vapors may autoignite as result of reaching [[Boiling liquid expanding vapor explosion|boiling liquid pressure]].<ref>{{Cite web |last=Husting |first=Chad |date=2019-08-18 |title=Paraffin Wax – an Exothermic Reaction: Caution |url=https://www.chemedx.org/blog/paraffin-wax-exothermic-reaction-caution |access-date=2023-04-18 |website=Chemical Education Xchange |language=en}}</ref>


== History ==
== History ==
Paraffin wax was first created in 1830 by German chemist [[Carl Reichenbach|Karl von Reichenbach]] when he attempted to develop a method to efficiently separate and refine waxy substances naturally occurring in petroleum. Paraffin represented a major advance in the candlemaking industry, because it burned cleanly and was cheaper to manufacture than other candle fuels. Paraffin wax initially suffered from a low melting point. This was remedied by adding [[stearic acid]]. The production of paraffin wax enjoyed a boom in the early 20th century due to the growth of the oil and meatpacking industries, which created paraffin and stearic acid as byproducts.<ref name="auto"/>
Paraffin wax was first created in 1830 by German chemist [[Carl Reichenbach|Karl von Reichenbach]] when he attempted to develop a method to efficiently separate and refine waxy substances naturally occurring in petroleum. Paraffin represented a major advance in the candle-making industry because it burned cleanly and was cheaper to manufacture than other candle fuels such as [[beeswax]] and [[tallow]]. Paraffin wax initially suffered from a low melting point. This was remedied by adding [[stearic acid]]. The production of paraffin wax enjoyed a boom in the early 20th century due to the growth of the oil and meatpacking industries, which created paraffin and stearic acid as byproducts.<ref name="auto"/>


== Manufacturing ==
== Manufacturing ==
The feedstock for paraffin is [[Petroleum product#Specialty and By-products|slack wax]], which is a mixture of oil and wax, a byproduct from the refining of lubricating oil.
The feedstock for paraffin is [[Petroleum product#Specialty and By-products|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 [[solvent]]s 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).<ref>{{cite web |title=Paraffin Wax (Fully Refined) |url=http://www.barasatwax.com/fullyrefined.php |publisher=Barasat Wax Refiner |access-date=21 December 2012 |archive-url=https://web.archive.org/web/20130720100551/http://www.barasatwax.com/fullyrefined.php |archive-date=20 July 2013 |url-status=dead }}</ref> 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.<ref>{{cite web |title=Wax Refining |url=http://igiwax.com/reference/wax-refining.html |publisher=The International Group, Inc. |access-date=21 December 2012}}</ref><ref>{{cite web |title=Paraffin wax |url=http://bitumenengineering.com/materials/paraffin-wax |publisher=Bitumen Engineering |access-date=21 December 2012 |archive-url=https://web.archive.org/web/20120630024342/http://bitumenengineering.com/materials/paraffin-wax |archive-date=30 June 2012 |url-status=dead }}</ref><ref>{{cite web |title=Manufacturing Process |url=http://www.barasatwax.com/mp.php |publisher=Barasat Wax Refiner |access-date=21 December 2012 |archive-url=https://web.archive.org/web/20130720100707/http://barasatwax.com/mp.php |archive-date=20 July 2013 |url-status=dead }}</ref>
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 [[solvent]]s 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 to be (semi-refined versus fully refined).<ref>{{cite web |title=Paraffin Wax (Fully Refined) |url=http://www.barasatwax.com/fullyrefined.php |publisher=Barasat Wax Refiner |access-date=21 December 2012 |archive-url=https://web.archive.org/web/20130720100551/http://www.barasatwax.com/fullyrefined.php |archive-date=20 July 2013 |url-status=dead }}</ref> 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.<ref>{{cite web |title=Wax Refining |url=http://igiwax.com/reference/wax-refining.html |publisher=The International Group, Inc. |access-date=21 December 2012 |archive-date=10 December 2012 |archive-url=https://web.archive.org/web/20121210142737/http://igiwax.com/reference/wax-refining.html |url-status=dead }}</ref><ref>{{cite web |title=Paraffin wax |url=http://bitumenengineering.com/materials/paraffin-wax |publisher=Bitumen Engineering |access-date=21 December 2012 |archive-url=https://web.archive.org/web/20120630024342/http://bitumenengineering.com/materials/paraffin-wax |archive-date=30 June 2012 |url-status=dead }}</ref><ref>{{cite web |title=Manufacturing Process |url=http://www.barasatwax.com/mp.php |publisher=Barasat Wax Refiner |access-date=21 December 2012 |archive-url=https://web.archive.org/web/20130720100707/http://barasatwax.com/mp.php |archive-date=20 July 2013 |url-status=dead }}</ref>


== Applications ==
== Applications ==
In industrial applications, it is often useful to modify the crystal properties of the paraffin wax, typically by adding [[Branching (polymer chemistry)|branching]] to the existing carbon backbone chain. The modification is usually done with additives, such as [[Ethylene-vinyl acetate|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 (metalworking)|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 industrial applications, it is often useful to modify the crystal properties of the paraffin wax, typically by adding [[Branching (polymer chemistry)|branching]] to the existing carbon backbone chain. The modification is usually done with additives, such as [[Ethylene-vinyl acetate|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 (metalworking)|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 histology or pathology laboratory, paraffin wax is used to impregnate tissue prior to sectioning thin samples. 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 several hours, then set in a mold with wax to cool and solidify. Sections are then cut on a [[microtome]].
In a histology or pathology laboratory, paraffin wax is used to impregnate tissue prior to sectioning thin samples. Water is removed from the tissue through ascending strengths of alcohol (75% to absolute), and then the alcohol is cleared in an organic solvent such as [[xylene]]. The tissue is then placed in paraffin wax for several hours, then set in a mold with wax to cool and solidify. Sections are then cut on a [[microtome]].


=== Other uses ===
=== Other uses ===
* Agent for preparation of specimens for [[histology]]
* [[Candle]]-making
* Anti-caking agent, moisture repellent, and dustbinding coatings for [[fertilizers]]
* [[Wax carving]]
* [[Antiozonant]] agents: blends of paraffin and micro waxes are used in rubber compounds to prevent [[Ozone cracking|cracking]] of the rubber; the admixture of wax migrates to the surface of the product and forms a protective layer. The layer can also act as a [[release agent]], helping the product separate from its [[Molding (process)|mould]].<ref>{{harv|Freund|Mózes|1982|p=272}}</ref>
* [[Bicycle chain]] lubrication
* [[Bicycle chain]] lubrication
* Bullet lubricant – with other ingredients, such as olive oil and [[beeswax]]
* [[Candle]]-making
* Coatings for [[waxed paper]] or [[waxed cotton]]
* Coatings for [[waxed paper]] or [[waxed cotton]]
* Component of [[surfboard wax]], [[ski wax]], and [[Street skateboarding#Wax|skateboard wax]]
* [[Crayon]]s
* Food-grade paraffin wax:
* Food-grade paraffin wax:
** Shiny coating used in [[candy]]-making; although edible, it is nondigestible, passing through the body without being broken down
** Shiny coating used in [[candy]]-making; although edible, it is nondigestible, passing through the body without being broken down
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** Sealant for jars, cans, and bottles
** Sealant for jars, cans, and bottles
** Chewing gum additive
** Chewing gum additive
* [[Investment casting]]
* Anti-caking agent, moisture repellent, and dustbinding coatings for [[fertilizers]]
* Agent for preparation of specimens for [[histology]]
* Bullet lubricant – with other ingredients, such as olive oil and [[beeswax]]
* [[Phlegmatized|Phlegmatizing]] agent, commonly used to stabilise/desensitize [[high explosive]]s such as [[RDX]]
* [[Crayon]]s
* Solid propellant for [[hybrid rocket]] motors<ref>{{cite journal|last=Staff|date=Fall 2004|title=Rocket motor uses common household product for fuel|journal=OASIS Ocean Air Space Industry Site|volume=1|issue=3|pages=6|url=http://www.nasa.gov/centers/stennis/pdf/69281main_fall.pdf|access-date=28 November 2008}}</ref><ref>{{cite web |last1=Tabor |first1=Abigail |title=From Pedicures to the Peregrine Rocket, Paraffin Wax Proves Its Worth |url=https://www.nasa.gov/feature/ames/from-pedicures-to-the-peregrine-rocket-paraffin-wax-proves-its-worth |website=NASA.gov |access-date=26 March 2019|date=18 April 2017 }}</ref>
* Component of [[surfboard wax]], [[ski wax]], and [[Street skateboarding#Wax|skateboard wax]]
* Ink. Used as the basis for solid ink different color blocks of wax for thermal printers. The wax is melted and then sprayed on the paper producing images with a shiny surface
* Microwax:<ref>{{cite web|url=http://igiwax.com/igi-products/by-type/microcrystallinewax.html|title=Paraffin, microcrystalline, petrolatum, wax blends - Microcrystalline Wax|work=igiwax.com|access-date=29 April 2017}}</ref> [[food additive]], a [[glazing agent]] with [[E number]] E905
* [[Forensic investigation]]s: the nitrate test uses paraffin wax to detect nitrates and nitrites on the hand of a shooting suspect
* [[Forensic investigation]]s: the nitrate test uses paraffin wax to detect nitrates and nitrites on the hand of a shooting suspect
* Fuel for [[Fire breathing (circus act)|fire breathing]]
* [[Antiozonant]] agents: blends of paraffin and micro waxes are used in rubber compounds to prevent [[Ozone cracking|cracking]] of the rubber; the admixture of wax migrates to the surface of the product and forms a protective layer. The layer can also act as a [[release agent]], helping the product separate from its [[Molding (process)|mould]].<ref>{{harv|Freund|Mózes|1982|p=272}}</ref>
* [[Investment casting]]
* [[Lava Lamps|Lava lamps]]
* Manufacture of [[boiled leather]] armor and books
* Mechanical [[Wax thermostatic element|thermostats]] and [[Paraffin microactuator|actuators]], as an expansion medium for activating such devices<ref name=rogerboden/><ref>{{cite journal|last=Ogden|first=Sam|author2=Klintberg, Lena |author3=Thornell, Greger |author4=Hjort, Klas |author5= Bodén, Roger |title=Review on miniaturized paraffin phase change actuators, valves, and pumps|journal=Microfluidics and Nanofluidics|volume=17|pages=53–71|date=30 November 2013|doi=10.1007/s10404-013-1289-3|s2cid=85525659|url=http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-208904}}</ref>
* Mechanical [[Wax thermostatic element|thermostats]] and [[Paraffin microactuator|actuators]], as an expansion medium for activating such devices<ref name=rogerboden/><ref>{{cite journal|last=Ogden|first=Sam|author2=Klintberg, Lena |author3=Thornell, Greger |author4=Hjort, Klas |author5= Bodén, Roger |title=Review on miniaturized paraffin phase change actuators, valves, and pumps|journal=Microfluidics and Nanofluidics|volume=17|pages=53–71|date=30 November 2013|doi=10.1007/s10404-013-1289-3|s2cid=85525659|url=http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-208904}}</ref>
* Microwax:<ref>{{cite web|url=http://igiwax.com/igi-products/by-type/microcrystallinewax.html|title=Paraffin, microcrystalline, petrolatum, wax blends - Microcrystalline Wax|work=igiwax.com|access-date=29 April 2017|archive-date=19 October 2016|archive-url=https://web.archive.org/web/20161019214424/http://www.igiwax.com/igi-products/by-type/microcrystallinewax.html|url-status=dead}}</ref> [[food additive]], a [[glazing agent]] with [[E number]] E905
* As a [[Potting (electronics)|potting]] material to encapsulate electronic components such as [[Pick up (music technology)|guitar pickups]], [[transformer]]s, and [[inductor]]s, to prevent moisture ingress and to reduce [[Electromagnetically induced acoustic noise|electromagnetically-induced acoustic noise]] and [[Microphonics|microphonic effects]]
* Textile manufacturing processes, such as that used for [[Eisengarn]] thread.
* Thickening agent in many [[paintballs]]
* [[Moisturiser]] in [[toiletries]] and [[cosmetics]] such as [[Vaseline]].
* [[Moisturiser]] in [[toiletries]] and [[cosmetics]] such as [[Vaseline]].
* Prevents oxidation on the surface of polished steel and iron<ref>
{{cite web |last=Dick |first=William B |title=Encyclopedia Of Practical Receipts And Processes |publisher=Dick and Fitzgerald |location=New York |year=1872 |url=http://chestofbooks.com/reference/Encyclopedia-Of-Practical-Receipts-And-Processes/Steel-Part-6.html |access-date=25 October 2013}}</ref>
* [[Phase change material]] for [[thermal energy storage]]
** Used by [[MESSENGER]] (Mercury spacecraft), when the spacecraft was unable to radiate excessive heat.<ref>{{cite web |url=https://pds.nasa.gov/ds-view/pds/viewInstrumentProfile.jsp?INSTRUMENT_ID=MDIS-NAC&INSTRUMENT_HOST_ID=MESS |title= Instrument Information |work= [[NASA]] |date= 2007 |access-date= 24 January 2017}}</ref>
* Manufacture of [[boiled leather]] armor and books
* [[Neutron radiation]] shielding
* [[Neutron radiation]] shielding
* [[Phase change material]] for [[thermal energy storage]]
** Used by [[MESSENGER]] (Mercury spacecraft), when the spacecraft was unable to radiate excessive heat.<ref>{{cite web |url=https://pds.nasa.gov/ds-view/pds/viewInstrumentProfile.jsp?INSTRUMENT_ID=MDIS-NAC&INSTRUMENT_HOST_ID=MESS |title= Instrument Information |work= [[NASA]] |date= 2007 |access-date= 24 January 2017}}</ref>{{failed verification|date=April 2024}}{{dead link|date=April 2024}}
* [[Phlegmatized|Phlegmatizing]] agent, commonly used to stabilise/desensitize [[high explosive]]s such as [[RDX]]
* [[Potting (electronics)|Potting]] material to encapsulate electronic components such as [[Pick up (music technology)|guitar pickups]], [[transformer]]s, and [[inductor]]s, to prevent moisture ingress and to reduce [[electromagnetically induced acoustic noise]] and [[Microphonics|microphonic effects]]
* Prevents [[Redox|oxidation]] on the surface of [[Steel|polished steel]] and [[iron]]<ref>
{{cite web |last=Dick |first=William B |title=Encyclopedia Of Practical Receipts And Processes |publisher=Dick and Fitzgerald |location=New York |year=1872 |url=http://chestofbooks.com/reference/Encyclopedia-Of-Practical-Receipts-And-Processes/Steel-Part-6.html |access-date=25 October 2013}}</ref>
* Solid [[ink]] color blocks of wax for [[Thermal printing|thermal printers]]. The wax is melted and then sprayed on the paper producing images with a shiny surface
* Solid propellant for [[hybrid rocket]] motors<ref>{{cite journal|last=Staff|date=Fall 2004|title=Rocket motor uses common household product for fuel|journal=OASIS Ocean Air Space Industry Site|volume=1|issue=3|pages=6|url=http://www.nasa.gov/centers/stennis/pdf/69281main_fall.pdf|access-date=28 November 2008}}</ref><ref>{{cite web |last1=Tabor |first1=Abigail |title=From Pedicures to the Peregrine Rocket, Paraffin Wax Proves Its Worth |url=https://www.nasa.gov/feature/ames/from-pedicures-to-the-peregrine-rocket-paraffin-wax-proves-its-worth |website=NASA.gov |access-date=26 March 2019 |date=18 April 2017 |archive-date=27 March 2019 |archive-url=https://web.archive.org/web/20190327005729/https://www.nasa.gov/feature/ames/from-pedicures-to-the-peregrine-rocket-paraffin-wax-proves-its-worth/ |url-status=dead }}</ref>
* Textile manufacturing processes, such as that used for [[Eisengarn]] thread
* Thickening agent in many [[paintballs]]
* Wax baths for [[Occupational therapy|occupational]] and [[Physical therapy|physical]] therapies and [[Manicure#Paraffin wax treatments|cosmetic treatments]]
* Wax baths for [[Occupational therapy|occupational]] and [[Physical therapy|physical]] therapies and [[Manicure#Paraffin wax treatments|cosmetic treatments]]
* [[Wax carving]]
** Paraffin is effective in the treatment of [[Osteoporosis]] of the hand joints. Treatment consists of dip-wrapped paraffin bath therapy for 15 minutes until paraffin cooled for five days a weeks. The use of paraffin wax bath has been shown to decrease pain at rest and during ADLs compared to groups who did not receive wax therapy.<ref>{{Cite journal |last=Beasley |first=Jeanine |last2=Ward |first2=LeeAnn |last3=Knipper-Fisher |first3=Katie |last4=Hughes |first4=Katia |last5=Lunsford |first5=Dianna |last6=Leiras |first6=Claudia |date=April 2019 |title=Conservative therapeutic interventions for osteoarthritic finger joints: A systematic review |url=https://linkinghub.elsevier.com/retrieve/pii/S0894113017302740 |journal=Journal of Hand Therapy |language=en |volume=32 |issue=2 |pages=153–164.e2 |doi=10.1016/j.jht.2018.01.001}}</ref> Paraffin Wax bath is a proven and effective treatment for Osteoporosis.
* Used for [[wood finishing]]
* [[Wood finishing]]
* Used as a fuel for [[Fire breathing (circus act)|fire breathing]]
* Used in [[Lava Lamps]]


== Occupational safety ==
== 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&nbsp;mg/m<sup>3</sup> over an 8-hour workday.<ref>{{Cite web|title = CDC - NIOSH Pocket Guide to Chemical Hazards - Paraffin wax fume|url = https://www.cdc.gov/niosh/npg/npgd0477.html|website = cdc.gov|access-date = 27 November 2015}}</ref>
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&nbsp;mg/m<sup>3</sup> over an 8-hour workday.<ref>{{Cite web|title = CDC NIOSH Pocket Guide to Chemical Hazards Paraffin wax fume|url = https://www.cdc.gov/niosh/npg/npgd0477.html|website = cdc.gov|access-date = 27 November 2015}}</ref>


== See also ==
== See also ==
Line 151: Line 153:


== References ==
== References ==

{{reflist}}
{{reflist}}


== External links ==
== External links ==
{{commons category}}
{{commons category}}
* "[https://books.google.com/books?id=p4o9AQAAIAAJ Odd Uses of Paraffin]", [[Scientific American]], 13 July 1878, p.&nbsp;19


* "[https://books.google.com/books?id=p4o9AQAAIAAJ Odd Uses of Paraffin]", [[Scientific American]], 13 July 1878, p.&nbsp;19
{{Authority control}}
{{Authority control}}



Latest revision as of 00:07, 22 November 2024

Paraffin wax
Identifiers
E number E905 (glazing agents, ...)
UNII
Properties
CnH2n+2
Appearance White solid[1]
Odor Odorless
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).
Paraffin candle

Paraffin wax (or petroleum wax) is a soft colorless solid derived from petroleum, coal, or oil shale that consists of a mixture of hydrocarbon molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and begins to melt above approximately 37 °C (99 °F),[2] and its boiling point is above 370 °C (698 °F).[2] Common applications for paraffin wax include lubrication, electrical insulation, and candles;[3] dyed paraffin wax can be made into crayons.

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.[4]

In chemistry, paraffin is used synonymously with alkane, indicating hydrocarbons with the general formula CnH2n+2. The name is derived from Latin parum ("very little") + affinis, meaning "lacking affinity" or "lacking reactivity", referring to paraffin's unreactive nature.[5]

Properties

[edit]

Paraffin wax is mostly found as a white, odorless, flavourless, waxy solid, with a typical melting point between about 46 and 68 °C (115 and 154 °F),[6] and a density of around 900 kg/m3.[7] It is insoluble in water, but soluble in ether, benzene, and certain esters. Paraffin is unaffected by most common chemical reagents but burns readily.[8] Its heat of combustion is 42 MJ/kg.[9]

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.[10] This is better than nearly all other materials except some plastics (notably PTFE). It is an effective neutron moderator and was used in James Chadwick's 1932 experiments to identify the neutron.[11][12]

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 per kelvin) and a heat of fusion of 200–220 J⋅g−1.[13] Paraffin wax phase-change cooling coupled with retractable radiators was used to cool the electronics of the Lunar Roving Vehicle during the crewed missions to the Moon in the early 1970s.[14] Wax expands considerably when it melts and so is used in wax element thermostats for industrial, domestic and, particularly, automobile purposes.[15][16]

If pure paraffin wax melted to the approximate flash point in a half open glass vessel which is then suddenly cooled down, then its vapors may autoignite as result of reaching boiling liquid pressure.[17]

History

[edit]

Paraffin wax was first created in 1830 by German chemist Karl von Reichenbach when he attempted to develop a method to efficiently separate and refine waxy substances naturally occurring in petroleum. Paraffin represented a major advance in the candle-making industry because it burned cleanly and was cheaper to manufacture than other candle fuels such as beeswax and tallow. Paraffin wax initially suffered from a low melting point. This was remedied by adding stearic acid. The production of paraffin wax enjoyed a boom in the early 20th century due to the growth of the oil and meatpacking industries, which created paraffin and stearic acid as byproducts.[4]

Manufacturing

[edit]

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 to be (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

[edit]

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

Other uses

[edit]

Occupational safety

[edit]

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

[edit]

References

[edit]
  1. ^ a b c Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  2. ^ a b 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. ^ Raw materials and candles production processes Archived 21 March 2020 at the Wayback Machine, AECM
  4. ^ a b "History of Candles". National Candle Association. Retrieved 25 February 2016.
  5. ^ "Paraffin, n". Oxford English Dictionary. Oxford, England: Oxford University Press. March 2009.
  6. ^ Nasser, William E (1999). "Waxes, Natural and Synthetic". In McKetta, John J (ed.). Encyclopedia of Chemical Processing and Design. Vol. 67. New York: Marcel Dekker. p. 17. ISBN 978-0-8247-2618-8. This can vary widely, even outside the quoted range, according to such factors as oil content and crystalline structure.
  7. ^ Kaye, George William Clarkson; Laby, Thomas Howell. "Mechanical properties of materials". Kaye and Laby Tables of Physical and Chemical Constants. National Physical Laboratory. Archived from the original on 11 March 2008. Retrieved 25 October 2013.
  8. ^ 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.
  9. ^ Wiener, Harry (January 1947). "Structural Determination of Paraffin Boiling Points". Journal of the American Chemical Society. 69 (1): 17–20. doi:10.1021/ja01193a005. ISSN 0002-7863. PMID 20291038.
  10. ^ "Electrical insulating materials". Kaye and Laby Tables of Physical and Chemical Constants. National Physical Laboratory. 1995. Archived from the original on 27 September 2007. Retrieved 25 October 2013.
  11. ^ "Attenuation of fast neutrons: neutron moderation and diffusion". Kaye and Laby Tables of Physical and Chemical Constants. National Physical Laboratory. Archived from the original on 29 September 2007. Retrieved 25 October 2013.
  12. ^ Rhodes, Richard (1981). The Making of the Atomic Bomb. New York: Simon and Schuster. p. 163. ISBN 978-0-671-44133-3.
  13. ^ "Specific Heat Capacity". Diracdelta.co.uk Science and Engineering Encyclopedia. Dirac Delta Consultants Ltd, Warwick, England. Archived from the original on 4 August 2007. Retrieved 25 October 2013.
  14. ^ Dean, W. G.; Karu, Z. S. (February 1993). "Space Station thermal storage/refrigeration system research and development". Final Report Lockheed Missiles and Space Co.
  15. ^ Wax-pellet thermostat United States Patent 4948043
  16. ^ a b 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.
  17. ^ Husting, Chad (18 August 2019). "Paraffin Wax – an Exothermic Reaction: Caution". Chemical Education Xchange. Retrieved 18 April 2023.
  18. ^ "Paraffin Wax (Fully Refined)". Barasat Wax Refiner. Archived from the original on 20 July 2013. Retrieved 21 December 2012.
  19. ^ "Wax Refining". The International Group, Inc. Archived from the original on 10 December 2012. Retrieved 21 December 2012.
  20. ^ "Paraffin wax". Bitumen Engineering. Archived from the original on 30 June 2012. Retrieved 21 December 2012.
  21. ^ "Manufacturing Process". Barasat Wax Refiner. Archived from the original on 20 July 2013. Retrieved 21 December 2012.
  22. ^ (Freund & Mózes 1982, p. 272)
  23. ^ Ogden, Sam; Klintberg, Lena; Thornell, Greger; Hjort, Klas; Bodén, Roger (30 November 2013). "Review on miniaturized paraffin phase change actuators, valves, and pumps". Microfluidics and Nanofluidics. 17: 53–71. doi:10.1007/s10404-013-1289-3. S2CID 85525659.
  24. ^ "Paraffin, microcrystalline, petrolatum, wax blends - Microcrystalline Wax". igiwax.com. Archived from the original on 19 October 2016. Retrieved 29 April 2017.
  25. ^ "Instrument Information". NASA. 2007. Retrieved 24 January 2017.
  26. ^ Dick, William B (1872). "Encyclopedia Of Practical Receipts And Processes". New York: Dick and Fitzgerald. Retrieved 25 October 2013.
  27. ^ 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.
  28. ^ Tabor, Abigail (18 April 2017). "From Pedicures to the Peregrine Rocket, Paraffin Wax Proves Its Worth". NASA.gov. Archived from the original on 27 March 2019. Retrieved 26 March 2019.
  29. ^ "CDC – NIOSH Pocket Guide to Chemical Hazards – Paraffin wax fume". cdc.gov. Retrieved 27 November 2015.
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