The Collaborative Dictionary

lipid \lip"id\ n. [Gr. li`pos fat.] (Chem., Biochem.) Any of a variety of oily or greasy organic compounds found as major structural components of living cells; they are insoluble in water but soluble in organic solvents such as alcohol and ether, and include the common fats, cholesterol and other steroids, phospholipids, sphingolipids, waxes, and fatty acids; some of the lipids, together with proteins and carbohydrates, form an essential structural component of living cells, as in the cell walls and membranes. The term lipid refers to its solubility in nonpolar solvents, and has no significance with regard to chemical structure. Syn: lipide, lipoid. [WordNet 1.5]

English

Noun

waxes

1. Plural of wax

Verb

waxes

1. third-person singular of wax

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.

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. Paraffin waxes are hydrocarbons, mixtures of alkanes usually in a homologous series of chain lengths.

Uses of wax

Waxes are used to impregnate and coat paper and card, to waterproof it or make it resistant to staining, or to modify its surface properties. Waxes are also used in wax polishes for furniture and other wood products, footwear and vehicles, as mould release agents in mould making, as a coating for Edam and Gouda 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. Chanukah, the Jewish Festival of Lights which centers on the lighting of candles, dates back to 165 BCE. There are several Biblical references to candles, and the Emperor Constantine is reported to have called for the use of candles during an Easter service in the 4th century CE. Candles continue to be used to by Christians in worship as symbols of the light of Christ. Candles have also played a role in paganism, in Wiccan ceremonies, and in modern humanist festivals. 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 coloured pigments added has been used as a medium in encaustic painting, and is used today in the manufacture of crayons and coloured 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 coloured with pigments, and both beeswax and lanolin are used in other cosmetics. Also, the sports of skiing, snowboarding and skateboarding often use wax to enhance the performance. See Mojo wax.

Wax types

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.

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)
• Soy wax - from soybean oil.

Mineral waxes

• Ceresin waxes
• Montan wax - extracted from lignite and brown coal
• Ozocerite - found in lignite beds
• Peat waxes

Petroleum waxes

• Paraffin wax - made of long-chain alkane hydrocarbons
• Microcrystalline wax - with very fine crystalline structure

Synthetic waxes

• Polyethylene waxes - based on polyethylene
• Fischer-Tropsch waxes
• Chemically modified waxes - usually esterified or saponified
• substituted amide waxes
• polymerized α-olefins

References

External links

• Waxes
• www.igiwax.com, resource for wax product research
• www.microcrystallinewax.net, resource for microcrystalline wax research