乳胶
维基百科，自由的百科全书
天然的乳膠是指從樹木中抽取的樹液，在空氣中會凝固。它是一種混合的乳劑，成分包括蛋白質、生物鹼（en:alkaloid）、澱粉、糖類、植物油（en:Vegetable oil）、單寧酸、樹脂、樹膠（en:Natural Gum）等等。大多植物的乳膠都是白色的，但是也有黃色、橘色或紅色的乳膠。
乳膠亦可指樹液提煉後的延展性物質，或是將單體聚合而成的合成（en:chemical synthesis）物，以界面活性劑（en:surfactant）乳化。
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[编辑] 原料
The cells or 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 stem or root. The cell walls 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 tree, 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.
In the milkweed and 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, leaves, and sometimes the fruits. It is particularly noticeable in the cortical tissues.
[编辑] Function and usage
Latex has been attributed to many plant functions. 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 fungi and 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.
Latex has many uses, from clothing to paint, but its first and foremost is rubber. Chicle, widely used as a base for chewing gum, is another latex product. Latex paint uses synthetic latex as a binder, which is not flammable, has little odor, and cures to form a dry paint film. Finally, poppy latex is a source of opium and its many derivatives.
Some people have a serious latex allergy, and exposure to latex or rubber products such as rubber gloves or condoms can cause anaphylactic shock. As latex has a protein found also in bananas, care should be taken to ensure people are not allergic to both. Guayule latex is hypoallergenic and is being researched as a substitute to the allergy inducing Hevea latexes.
[编辑] Latex clothing
- 主條目：Latex clothing
Latex is used in many types of clothing. It is different from rubber in that it is less refined and often thinner. Worn on the body (or applied directly by painting) it tends to be skin-tight, producing a "second skin" effect. It has a more shiny finish than rubber.
Latex as a clothing material is especially common in fetish fashion and at fetish clubs, and there are several magazines dedicated to the use and wearing of it.
