Latex 18231 220968299 2008-06-22T13:10:49Z 65.95.77.81 /* Uses of latex */ {{otheruses2|latex}} {{Unreferenced|date=May 2007}} [[Image:Latex-production.jpg|thumb|250px|right|The extraction of latex from a [[tree]]; latex is used in [[rubber]] production]] '''Latex''' refers generically to a stable dispersion ([[emulsion]]) of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic. Latex as found in nature is the milky [[Sap (plant)|sap]] of many plants that coagulates on exposure to air. It is a complex emulsion in which [[protein]]s, [[alkaloid]]s, [[starch]]es, [[sugar]]s, [[Vegetable oil|oil]]s, [[tannin]]s, [[resin]]s and [[Natural gum|gum]]s are found. In most plants, latex is white, but some have yellow, orange, or scarlet latex. The word is also used to refer to natural latex [[rubber]]; particularly for non-[[vulcanization|vulcanized]] rubber. Such is the case in products like latex [[condom]]s and [[latex clothing]]. It can also be made [[chemical synthesis|synthetically]] by [[polymerization|polymerizing]] a [[monomer]] that has been [[emulsion|emulsified]] with [[surfactant]]s. The term ''latex'' is attributed to [[Charles Marie de la Condamine]], which is derived from ''leche'' the Spanish word for [[milk]].<ref>http://www.bouncing-balls.com/timeline/people/nr_condamine.htm</ref> ==Sources== The [[cell (biology)|cells]] or [[Vascular tissue|vessels]] in which latex is found make up the laticiferous system, which forms in two very different ways. In many plants, the [[laticiferous]] system is formed from rows of cells laid down in the [[meristem]] of the [[Plant stem|stem]] or [[root]]. The [[cell wall]]s between these cells are dissolved so that continuous tubes, called latex vessels, are formed. This method of formation is found in the [[poppy]] family, in the [[rubber]] trees ([[Para rubber tree]] and ''[[Castilla elastica]]''), and in the Cichorieae, a section of the Family [[Asteraceae]] distinguished by the presence of latex in its members. [[Dandelion]], [[lettuce]], [[hawkweed]] and [[salsify]] are members of the Cichorieae. It is also present in another member of the Asteraceae, the [[guayule]] plant. In the [[Asclepias|milkweed]] and [[Euphorbiaceae|spurge]] families, on the other hand, the laticiferous system is formed quite differently. Early in the development of the seedling latex cells differentiate, and as the plant grows these latex cells grow into a branching system extending throughout the plant. In the mature plant, the entire laticiferous system is descended from a single cell or group of cells present in the [[embryo]]. The laticiferous system is present in all parts of the mature plant, including roots, stems, [[leaf|leaves]], and sometimes the [[fruit]]s. It is particularly noticeable in the [[Cortex (botany)|cortical]] tissues. Several members of the fungal kingdom also produce latex upon injury. Notable are the [[lactarius|milk-caps]] such as ''[[Lactarius deliciosus]]''. ==Natural function of latex== {{Citations missing|date=May 2008}} [[Image:20070104rubberlatex.jpg|thumb|300px|Rubber latex|right]] Many plant functions have been attributed to latex. Some regard it as a form of stored food, while others consider it an excretory product in which waste products of the plant are deposited. Still others believe it functions to protect the plant in case of injuries; drying to form a protective layer that prevents the entry of [[fungus|fungi]] and [[bacterium|bacteria]]. Similarly, it may provide some protection against browsing animals, since in some plants latex is very bitter or even poisonous. It may be that latex fulfills all of these functions to varying degrees in the numerous plant species in which it occurs. ==Uses of latex== The latex of many species can be processed to produce other materials. Natural [[rubber]] is the most important product obtained from latex; more than 12,000 plant species yield latex containing rubber, though in the vast majority of those species the rubber is not suitable for commercial use.<ref name='Bowers'>{{cite book | last = Bowers | first = J.E. |title=Natural Rubber-Producing Plants for the United States | publisher=National Agricultural Library |location=Beltsville, MD |year=1990 |oclc=28534889 |pages=pp. 1,3}}</ref>. Latex is also used as a binding agent in latex [[paint]]. [[Balatá]] and [[gutta percha]] latex contain an inelastic polymer related to rubber. Latex from the [[chicle]] and [[jelutong]] trees is used in [[chewing gum]]. [[Poppy]] latex is a source of [[opium]] and its many derivatives. Latex may also be used in different brands of [[condoms]] ==Latex clothing== {{main|Latex clothing}} Latex is used in many types of [[clothing]]. It is different from [[rubber]] in that it is less refined and often thinner{{Fact|date=January 2008}}. Worn on the body (or applied directly by painting) it tends to be skin-tight, producing a "second skin" effect. It has a shinier finish than rubber. ==Allergic reactions== {{main|Latex allergy}} Some people have a serious [[latex allergy]], and exposure to latex products such as [[latex glove]]s can cause [[anaphylactic shock]]. [[Guayule]] latex is [[hypoallergenic]] and is being researched as a substitute to the allergy-inducing [[Hevea]] latexes. Some allergic reactions are not from the latex but from residues of other ingredients used to process the latex into clothing, gloves, foam, etc. These allergies are usually referred to as ''multiple chemical sensitivity'' (MCS). ==Notes== {{reflist|1}} ==External links== * [http://www.medicalexamglove.com/latex_gloves/managing_latex_sensitivity.html Latex Allergy and Sensitivity] * [http://www.webmd.com/content/pages/10/1625_50518.htm Latex Allergies] * [http://aaalatex.com/content/comments.asp?id=193 Latex Transportation] {{Commons|Latex}} [[Category:Materials]] [[Category:Sculpture materials]] [[Category:Nonwoven fabrics]] [[bg:Латекс]] [[ca:Làtex]] [[cs:Latex]] [[da:Latex]] [[de:Milchsaft]] [[es:Látex]] [[eo:Laktosuko]] [[fr:Latex (matériau)]] [[id:Lateks]] [[it:Lattice]] [[lb:Latex]] [[nl:Latex]] [[ja:ラテックス]] [[no:Lateks]] [[pl:Lateks]] [[pt:Látex]] [[ru:Латекс]] [[simple:Latex]] [[sk:Latex]] [[fi:Lateksi]] [[sv:Latex]] [[th:ยางธรรมชาติ]] [[tr:Lastik]] [[uk:Латекс]]