Wax
From Wikipedia, the free encyclopedia
Wax has traditionally referred to a substance that is secreted by bees (beeswax) and used by them in constructing their honeycombs.
It is an imprecisely defined term generally understood to be a substance with properties similar to beeswax, namely
- plastic (malleable) at normal ambient temperatures
- a melting point above approximately 45 °C (113 °F) (which differentiates waxes from fats and oils)
- a relatively low viscosity when melted (unlike many plastics)
- insoluble in water
- hydrophobic
Waxes may be natural secretions of plants or animals, artificially produced by purification from natural petroleum or completely synthetic. In addition to beeswax, carnauba (a plant epicuticular wax) and paraffin (a petroleum wax) are commonly encountered waxes which occur naturally. Earwax is an oily substance found in the human ear. Some artificial materials such as silicone wax that exhibit similar properties are also described as wax or waxy.
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[edit] Wax chemistry
Chemically, a wax is a type of lipid that may contain a wide variety of long-chain alkanes, esters, polyesters and hydroxy esters of long-chain primary alcohols and fatty acids. They are usually distinguished from fats by the lack of triglyceride esters of glycerin (propan-1,2,3-triol) and three fatty acids. In addition to the esters that contribute to the high melting point and hardness of carnauba wax, the epicuticular waxes of plants are mixtures of substituted long-chain aliphatic hydrocarbons, containing alkanes, fatty acids, primary and secondary alcohols, diols, ketones, aldehydes.[1] Paraffin waxes are hydrocarbons, mixtures of alkanes usually in a homologous series of chain lengths.
[edit] Uses of wax
Waxes are used to make wax paper, impregnating and coating paper and card to waterproof it or make it resistant to staining, or to modify its surface properties. Waxes are also used in shoe polishes, wood polishes, and automotive polishes, as mold release agents in mold making, as a coating for many cheeses, and to waterproof leather and fabric. Wax has been used since antiquity as a temporary, removable model in lost-wax casting of gold, silver and other materials.
Waxes and hard fats such as tallow have long been use to make candles, used for lighting and decoration in a number of religious traditions, including Christianity and Hinduism, as well as various neo-pagan religions such as Wicca. The Emperor Constantine is reported to have called for the use of candles during an Easter service in the 4th century AD. Candles continue to be used to by Christians[2] in worship as symbols of the light of Christ. In the Roman Catholic Church, beeswax candles are used, since a colony of bees is a celibate sisterhood with a single mother.[3] Candles of wax or tallow took the place of lamps used in various Jewish rituals such as the Sabbath lights; in the Havdalah ceremony; and the Hanukkah lights. A synagogue had to be well lit, and pious folk used to donate candles for the purpose. On the basis of the verse: 'The soul of man is a candle of the Lord' a special candle which burns twenty-four hours is kindled on the anniversary of the death of a near relative (Yahrzeit) and often two lighted candles are placed at the head of the corpse awaiting burial.[4]. Candles have also played a role in pagan religions and in modern humanist festivals. Virtually all rituals in Wicca include the lighting of altar candles, where two main candles are often used to represent the God and the Goddess; and the lighting of candles is a central theme at the Wiccan holiday of Brigid or Imbolc, which is also known as Candlemas or the Feast of the Waxing Light. Wax candles were also used in secular life for lighting, signals in warfare, safety in travel and for time keeping, and are still in popular use today to provide soft lighting for meals and other social activities.
Wax with colored pigments added has been used as a medium in encaustic painting, and is used today in the manufacture of crayons and colored pencils. Carbon paper, used for making duplicate typewritten documents was coated with carbon black suspended in wax, typically montan wax, but has largely been superseded by photocopiers and computer printers. In another context, lipstick and mascara are blends of various fats and waxes colored with pigments, and both beeswax and lanolin are used in other cosmetics. Also, the sports of surfing, skiing, snowboarding and skateboarding often use wax to enhance the performance. Beeswax or coloured synthetic wax is used to decorate Easter eggs in the Czech Republic. Paraffin wax is used in making chocolate covered bon-bons. Wax is also used in wax bullets, which are used as simulation aids.
[edit] Wax types
[edit] Animal waxes
- Beeswax - produced by honey bees
- Chinese wax - produced by the scale insect Ceroplastes ceriferus
- Shellac wax - from the lac insect Kerria lacca
- Spermaceti - from the head cavities and blubber of the sperm whale
- Lanolin (wool wax) - from the sebaceous glands of sheep
- Ear wax - found in the human ear.
[edit] Vegetable waxes
- Bayberry wax - from the surface wax of the fruits of the bayberry shrub, Myrica faya
- Candelilla wax - from the Mexican shrubs Euphorbia cerifera and Euphorbia antisyphilitica
- Carnauba wax - from the leaves of the Carnauba palm, Copernica cerifera
- Castor wax - catalytically hydrogenated castor oil
- Esparto wax - a byproduct of making paper from esparto grass, (Macrochloa tenacissima)
- Japan wax - a vegetable triglyceride (not a true wax), from the berries of Rhus and Toxicodendron species
- Jojoba oil - a replacement for spermaceti, jojoba is pressed from the seeds of the jojoba bush, Simmondsia chinensis
- Ouricury wax - from the Brazilian feather palm, Syagrus coronata.
- Rice bran wax - obtained from rice bran (Oryza sativa)
- Soy wax - from soybean oil
[edit] Mineral waxes
- Ceresin waxes
- Montan wax - extracted from lignite and brown coal
- Ozocerite - found in lignite beds
- Peat waxes
[edit] Petroleum waxes
- Paraffin wax - made of long-chain alkane hydrocarbons
- Microcrystalline wax - with very fine crystalline structure
[edit] Synthetic waxes
- Polyethylene waxes - based on polyethylene
- Fischer-Tropsch waxes
- Chemically modified waxes - usually esterified or saponified
- substituted amide waxes
- polymerized α-olefins
[edit] References
- ^ EA Baker (1982) Chemistry and morphology of plant epicuticular waxes. In The Plant Cuticle. Ed. DF Cutler, KL Alvin, CE Price. Academic Press. ISBN 0 12 199920 3
- ^ The Hive and the Honey Bee, ed. Dadant & sons, revised 1975, p. 540
- ^ Butler, C.G. (1954) The world of the honeybee. Collins, New Naturalist series, No. 29
- ^ Jacobs, Louis (1995) "The Jewish Religion - a Companion" Oxford University Press
[edit] External links
- Waxes
- www.igiwax.com, resource for wax product research
- www.microcrystallinewax.net, resource for microcrystalline wax research
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