Editing Vulcanization (section)

==Vulcanization of silicones{{anchor|Room-temperature vulcanization|Room temperature vulcanization|Room-temperature vulcanisation|Room temperature vulcanisation|Room Temperature Vulcanization}}==
[[File:Silicone rubber keypad example 1.jpg|thumb|225px|An example of a [[silicone rubber keypad]] typical of LSR (Liquid [[Silicone Rubber]]) moulding]]
{{Main|RTV silicone}}
Room-temperature vulcanizing (RTV) [[silicone]] is constructed of reactive oil-based polymers combined with strengthening mineral fillers. There are two types of room-temperature vulcanizing silicone:
# RTV-1 (One-component systems); hardens due to the action of atmospheric humidity, a catalyst, and acetoxysilane. Acetoxysilane, when exposed to humid conditions, will form [[acetic acid]].<ref>{{cite web|title=MSDS for red RTV-Silicone|url=http://www.permatex.com/documents/msds/01_USA-English/81160.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.permatex.com/documents/msds/01_USA-English/81160.pdf |archive-date=2022-10-09 |url-status=live|access-date=24 June 2011}}</ref> The curing process begins on the outer surface and progresses through to its core. The product is packed in airtight cartridges and is either in a fluid or paste form. RTV-1 silicone has good adhesion, elasticity, and durability characteristics. The [[Shore durometer|Shore hardness]] can be varied between 18 and 60. Elongation at break can range from 150% up to 700%. They have excellent aging resistance due to superior resistance to UV radiation and weathering.
# RTV-2 (Two-component systems); two-component products that, when mixed, cure at room-temperature to a solid elastomer, a gel, or a flexible foam. RTV-2 remains flexible from {{convert|−80|to|250|C|F}}. Break-down occurs at temperatures above {{convert|350|C}}, leaving an inert [[dilicon dioxide|silica]] deposit that is non-flammable and non-combustible. They can be used for [[insulator (electricity)|electrical insulation]] due to their [[dielectric]] properties. Mechanical properties are satisfactory. RTV-2 is used to make flexible moulds, as well as many technical parts for industry and paramedical applications.