矽氧樹脂
维库，知识与思想的自由文库
7个分类: 正在翻譯的條目 | Adhesives | Cosmetic chemicals | Lubricants | 矽化合物 | Silicones | 来自中文维基百科
[编辑] 性质Some of the most useful properties of silicone include:
[编辑] 应用
[编辑] 化学术语在英语中，硅氧树脂(Silicone)经常与硅(Silicon)混淆。尽管硅氧树脂含有硅原子，但其并不只由硅原子组成。硅氧树脂具有和单质硅完全不同的物理性质。 硅氧树脂(Silicone)的英文名称由酮(Ketone)衍生而来。二甲基硅酮(Dimethylsilicone)具有与丙酮(Acetone)相似的分子式，从而被错误的推断两者具有相似的结构。类似的术语还有硅烷(Silane)，名称由甲烷(methane)衍生而来。真正具有硅氧双键的"硅酮"并不存在。聚硅醚(Polysiloxane)由于其早期的错误推断仍被称为硅酮(Silicone)。 [编辑] 使用[编辑] Sealants in building construction and maintenanceOne-part silicone sealants are in common use to seal gaps, joints and crevices in buildings. Silicones are abundantly available for this purpose, in professional, as well as retail grades. One-part silicones cure by absorbing atmospheric moisture, which helps in the professional installation. To make a very smooth silicone seal, apart from masking the edges with tape, if practical, professional caulkers often wet wooden spoons and assorted, hand-crafted wooden tools, which they soak in water with diluted dishsoap. The silicone will not stick to wet, soapy wood, which makes this ideal for creating a perfectly smooth surface. Do-it-yourselfers typically use a moistened finger to trace neat beads into silicone caulking. Similar methods work for urethane caulking, against which silicones compete quite heavily. White silicones frequently turn slightly yellow over time. The strength and reliability of silicone rubber is widely acknowledged in the construction industry. Automotive body manufacturing plants and paint shops must avoid the presence of all silicones, as a mere hint of its presence in any form can cause severe failures in automotive paints. Vendors and contractors in such plants are often requested to verify in writing that they will not bring any silicones into the plant. In the plumbing and automotive fields, silicone grease is often used as a lubricant. Automotive spark plug wires are often insulated by multiple layers of silicone. Such construction prevents spark from jumping to an adjacent wire, causing a misfire. It also minimizes RFI, which can interfere with an engine management computer. In plumbing, the grease is typically applied to O-rings in faucets and valves. In the automotive field, silicone grease is typically used as a lubricant for brake components since it is stable at high temperatures, is not water-soluble, and is far less likely than other lubricants to foul brake pads. [编辑] Cooking applicationsSilicone is also impregnated into parchment paper and used as a non-stick material for applications such as baking and steaming. The silicone also makes the paper heat- and grease-resistant. This allows the paper to line cookie sheets and act as a replacement for greasing, thereby speeding mass production of baked goods. It is also commonly used in pouch cooking, where ingredients are sealed into a container made of parchment paper and allowed to steam. Silicone rubber is also used to make utensils (notably spatulas) and bakeware. [编辑] Electronic componentsElectronic components are sometimes protected from environmental influence by enclosing them in silicone. This increases the stability against mechanical shock, radiation, vibration and especially the electrical insulation. Silicones are selected over polyurethane or epoxy encapsulation when a wide operating temperature range is required (-150 to 600 F). Silicones also have the advantage of little exothermic heat rise during cure, low toxicity, good electrical properties and high purity. Therefore it is used when durability and high performance are demanded of components under hard conditions, as in space (satellite technology).Silicones, however are relatively expensive and can be attacked by solvents. (See Resin casting for how silicones can be dispensed in circuit board production). [编辑] Menstrual cupsA Menstrual cup is a type of cup or barrier worn inside the vagina during menstruation to collect menstrual fluid. Menstrual cups are often made of silicone for its durability and reusability. [编辑] Silicone breast implantsControversy developed in the 1980s and 1990s around claims that the silicone gel in breast implants was responsible for a number of systemic health problems, including autoimmune diseases and cancer. Multiple lawsuits claiming injury from implants resulted in the 1998 bankruptcy of Dow Corning and a moratorium on the use of silicone implants for breast augmentation in the US and Canada pending study. However, multiple studies and expert review panels performed worldwide since then have consistently concluded that women with silicone breast implants are no more likely to develop systemic illness than women without breast implants. In 2006 both Health Canada and the US FDA adopted positions similar to other countries in permitting the use of silicone implants for cosmetic breast augmentation in their respective countries. [编辑] FirestopsSilicone foams have been used in North American as well as the Israeli Dimona nuclear reactor buildings in an attempt to firestop openings within fire-resistance rated wall and floor assemblies to prevent the spread of flames and smoke from one room to another. (The Israelis wisely switched to the somewhat more expensive yet much safer "elastomer" version of this product, which avoids most safety concerns associated with the foamed version.) Silicone foam firestops have been the subject of serious controversy and press attention due to lack of proper bounding and smoke development due to the pyrolysis of combustible components within the foam, hydrogen gas escape, shrinkage and cracking. These problems have been exposed by whistleblower Gerald W. Brown and have led to a large number or reportable events among licensees (operators of nuclear power plants) of the Nuclear Regulatory Commission (NRC). When properly installed, silicone foam firestops can be fabricated for building code compliance. Advantages include flexibility and high dielectric strength. Disadvantages include poor bounding, combustibility (hard to extinguish) and significant smoke development. [编辑] 参见
[编辑] 参考材料
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