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 or artificial. 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 that exhibit similar properties are also described as wax or waxy.

Chemically, a wax may be an ester of ethylene glycol (ethan-1,2-diol) and two fatty acids, as opposed to a fat which is an ester of glycerin (propan-1,2,3-triol) and three fatty acids. It may also be a combination of other fatty alcohols with fatty acids. It is a type of lipid.

[edit] Wax types

[edit] Animal and insect waxes

• Beeswax - produced by honey bees
• Chinese wax - produced by scale insects Coccus ceriferus
• Shellac wax - from the lac insect Coccus lacca
• Spermaceti - from the head cavities and blubber of the sperm whale
• Lanolin (wool wax) - from the sebaceous glands of sheep

[edit] Vegetable waxes

• Bayberry wax - from the surface of the berries of the bayberry shrub, Myrica faya
• Candelilla wax - from the Mexican shrubs Euphorbia cerifera and E. 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)

[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