Identifiers | |
---|---|
ECHA InfoCard | 100.029.375 |
E number | E905 (glazing agents, ...) |
UNII | |
CompTox Dashboard (EPA) | |
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 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. It is not to be confused with kerosene and other petroleum products that are sometimes called paraffin. [4]
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. [5]
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. [6]
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), [7] and a density of around 900 kg/m3. [8] It is insoluble in water, but soluble in ether, benzene, and certain esters. Paraffin is unaffected by most common chemical reagents but burns readily. [9] Its heat of combustion is 42 MJ/kg. [10]
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 PTFE). It is an effective neutron moderator and was used in James Chadwick's 1932 experiments to identify the neutron. [12] [13]
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. [14] 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. [15] Wax expands considerably when it melts and so is used in wax element thermostats for industrial, domestic and, particularly, automobile purposes. [16] [17]
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. [18]
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. [5]
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). [19] 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. [20] [21] [22]
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.
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. [32]
Mojito is a traditional Cuban punch. The cocktail often consists of five ingredients: white rum, sugar, lime juice, soda water, and mint. Its combination of sweetness, citrus, and herbaceous mint flavors is intended to complement the rum, and has made the mojito a popular summer drink.
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical science laboratory programs that include nanoscale science and technology, engineering, information technology, neutron research, material measurement, and physical measurement. From 1901 to 1988, the agency was named the National Bureau of Standards.
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from nuclear fission is passed to a working fluid, which in turn runs through steam turbines. These either drive a ship's propellers or turn electrical generators' shafts. Nuclear generated steam in principle can be used for industrial process heat or for district heating. Some reactors are used to produce isotopes for medical and industrial use, or for production of weapons-grade plutonium. As of 2022, the International Atomic Energy Agency reports there are 422 nuclear power reactors and 223 nuclear research reactors in operation around the world.
Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium in nuclear power plants. Nuclear decay processes are used in niche applications such as radioisotope thermoelectric generators in some space probes such as Voyager 2. Generating electricity from fusion power remains the focus of international research.
Gasoline or petrol is a petrochemical product characterized as a transparent, yellowish, and flammable liquid normally used as a fuel for spark-ignited internal combustion engines. When formulated as a fuel for engines, gasoline is chemically composed of organic compounds derived from the fractional distillation of petroleum and later chemically enhanced with gasoline additives. It is a high-volume profitable product produced in crude oil refineries.
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 a method of keeping time. Candles have been used for over two millennia around the world, and were a significant form of indoor lighting until the invention of other types of light sources. Although electric light has largely made candle use nonessential for illumination, candles are still commonly used for functional, symbolic and aesthetic purposes and in specific cultural and religious settings.
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 nonpolar organic solvents such as hexane, benzene and chloroform. Natural waxes of different types are produced by plants and animals and occur in petroleum.
Petroleum jelly, petrolatum, white petrolatum, soft paraffin, or multi-hydrocarbon, CAS number 8009-03-8, is a semi-solid mixture of hydrocarbons, originally promoted as a topical ointment for its healing properties. Vaseline has been an American brand of petroleum jelly since 1870.
The People's Liberation Army Air Force, also referred to as the Chinese Air Force (中国空军) or the People's Air Force (人民空军), is an aerial service branch of the People's Liberation Army. The Air Force is composed of five sub-branches: aviation, ground-based air defense, radar, Airborne Corps, and other support elements.
Wax play is a form of temperature play practiced in a BDSM context, in which wax from a candle is dripped onto a person's naked skin, in order to introduce a severe burning sensation to the skin.
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.
Pizza delivery is a service in which a pizzeria or pizza chain delivers a pizza to a customer. An order is typically made either by telephone, or over the internet, in which the customer can request pizza type and size, and other items to be delivered with it, commonly including soft drinks. Pizzas may be delivered in cardboard pizza boxes or delivery bags, and deliveries are made with either an automobile, motorized scooter, or bicycle. Customers can, depending on the provider, choose to pay online, or in person, with cash, credit card, debit card or other means. A delivery fee is sometimes charged, although free delivery is also common.
Calumet Specialty Products Partners, L.P. is a publicly traded U.S.-based company that was incorporated in 1919. It specializes in the manufacture of lubricating oils, solvents, waxes, packaged and synthetic specialty products, fuels and fuel-related products. The company operates 12 production, blending, and packaging facilities across North America. This includes locations in Princeton, Cotton Valley, and Shreveport, Louisiana; Burnham, Illinois; Dickinson, Texas; Muncie, Indiana; Karns City, Pennsylvania; and Great Falls, Montana. Calumet's specialized hydrocarbon products are distributed around the world to approximately 2,700 global customers.
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 (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 sticky 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.
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.
In chemistry, fractional crystallization is a stage-wise separation technique that relies on the liquid-solid phase change. It fractionates via differences in crystallization temperature and enables the purification of multi-component mixtures, as long as none of the constituents can act as solvents to the others. Due to the high selectivity of the solid – liquid equilibrium, very high purities can be achieved for the selected component.
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.
Crude oil is extracted from the bedrock before being processed in several stages, removing natural contaminants and undesirable hydrocarbons. This separation process produces mineral oil, which can in turn be denoted as paraffinic, naphthenic or aromatic. The differences between these different types of oils are not clear-cut, but mainly depend on the predominant hydrocarbon types in the oil. Paraffinic oil, for example, contains primarily higher alkanes, whereas naphthenic oils have a high share of cyclic alkanes in the mixture.
Wax emulsions are stable mixtures 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.
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