Everything about Paraffin totally explained
In chemistry,
paraffin is the common name for the
alkane hydrocarbons with the general formula C
nH
2n+2.
Paraffin wax refers to the solids with n=20–40.
The simplest paraffin molecule is that of
methane, CH
4, a gas at room temperature. Heavier members of the series, such as that of
octane C
8H
18, appear as liquids at room temperature. The solid forms of paraffin, called
paraffin wax, are from the heaviest molecules from C
20H
42 to C
40H
82. Paraffin wax was identified by
Carl Reichenbach in 1830.
Paraffin, or
paraffin hydrocarbon, is also the technical name for an alkane in general, but in most cases it refers specifically to a linear, or
normal alkane — whereas branched, or
isoalkanes are also called
isoparaffins. It is distinct from the fuel known in Britain and South Africa as
paraffin oil or just
paraffin, which is called
kerosene in much of the U.S., Australia and New Zealand.
The name is derived from the Latin
parum (= barely) +
affinis with the meaning here of "lacking
affinity", or "lacking
reactivity". This is because alkanes, being
non-polar and lacking in
functional groups, are very unreactive.
Wax
Paraffin wax (or simply "paraffin", but see alternative name for
kerosene, above) is mostly found as a white, odorless, tasteless,
waxy solid, with a typical melting point between about 47 °C to 64 °C, and having a density of around 0.9 g/cm
3. It is insoluble in water, but soluble in
ether,
benzene, and certain
esters. Paraffin is unaffected by most common chemical
reagents, but
burns readily.
Pure paraffin wax is an excellent electrical
insulator, with an electrical
resistivity of between
ohm metre. 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 .
Paraffin wax (C
25H
52) is an excellent material to store heat, having a
specific heat capacity of 2.14–2.9 J g
–1 K
–1 (
joule per
gram per
kelvin) and a
heat of fusion of 200–220 J g
–1. This property is exploited in modified
sheetrock for home building material: it's infused in the sheetrock during manufacture so as, when installed, it melts during the day, absorbing heat, and solidifies again at night, releasing the heat. Wax expands considerably when it melts and this allows its use in
thermostats for industrial, domestic and, particularly, automobile purposes.
Pure paraffin wax is rarely used for carving original models for
casting metal and other materials in the
lost wax process, as it's 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's 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.
Mineral oil
Liquid paraffin, or mineral oil, is a mixture of heavier alkanes, and has a number of names, including nujol, adepsine oil, alboline, glymol, medicinal paraffin, saxol, or USP mineral oil. It has a density of around 0.8 g/cm
3.
Liquid paraffin (medicinal) is used to aid bowel movement in persons suffering chronic constipation; it passes through the
alimentary canal without itself being taken into the body, but it limits the amount of water removed from the
stool. In the food industry, where it may be called "wax", it can be used as a lubricant in mechanical mixing, applied to baking tins to ensure that loaves are easily released when cooked and as a coating for fruit or other items requiring a "shiny" appearance for sale. It is often used in
infrared spectroscopy, as it has a relatively uncomplicated
IR spectrum. When the sample to be tested is made into a
mull (a very thick paste), liquid paraffin is added so it can be spread on the transparent (to infrared)
mounting plates to be tested.
Uses
Gaseous
Paraffin wax
Candle-making
Coatings for waxed paper or cloth
Food-grade paraffin wax:
- Shiny coating used in candy-making; although edible, it's nondigestible, passing right through the body without being broken down
- Coating for many kinds of hard cheese, like Edam cheese.
- Sealant for jars, cans, and bottles
- 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
Solid propellant for hybrid rocket motors
Component of surfwax, used for grip on surfboards in surfing
Component of glide wax, used on skis and snowboards.
Friction-reducer, for use on handrails and cement ledges, commonly used in skateboarding
Microwax(External Link
): food additive, a glazing agent with E number E905
Forensics aid: the nitrate test uses paraffin wax to detect nitrates and nitrites on the hand of a shooting suspect
Anti-ozonant agent: blends of paraffin and micro waxes are used in rubber compounds to prevent cracking of the rubber; the antiozonant waxes can be produced from synthetic waxes, FT wax, and Fischer Tropsch wax
Mechanical thermostats and actuators, as an expansion medium for activating such devices.
"Potting" guitar pickups, which reduce microphonic feedback caused from the subtle movements of the pole pieces
Wax baths for beauty and therapy purposes
Thickening agent in many Paintballs, as used by Crayola
An effective, although comedogenic, moisturiser in toiletries and cosmetics such as Vaseline.
Prevents oxidation on the surface of polished steel and ironFurther Information
Get more info on 'Paraffin'.
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