Formvar: Difference between revisions
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'''Formvar''' refers to any of several [[thermoplastic]] [[resins]] that are polyvinyl formals, which are polymers formed from [[polyvinyl alcohol]] and [[formaldehyde]] as [[copolymers]] with [[polyvinyl acetate]]. They are typically used as coatings, [[adhesives]], and molding materials.<ref>{{cite web|url=http://www.merriam-webster.com/dictionary/formvar|title=Formvar|year=2014|publisher=Merriam-Webster, Inc.|website=Merriam-Webster.com|accessdate=10 July 2014}}</ref> "Formvar" used to be the registered [[trade name]] of the polyvinyl formal resin produced by [[Monsanto Chemical Company]] in [[St. Louis, Missouri]]. That manufacturing unit was sold and formvar is now distributed under the name "Vinylec".<ref name="SPI">{{cite web|url=http://www.2spi.com/catalog/submat/formvar-resins.shtml|title=SPI-Chem Vinylec (Formvar) Resins|publisher=Structure Probe, Inc.|date=10 July 2014|accessdate=10 July 2014|website=2SPI.com}}</ref> |
'''Formvar''' refers to any of several [[thermoplastic]] [[resins]] that are polyvinyl formals, which are polymers formed from [[polyvinyl alcohol]] and [[formaldehyde]] as [[copolymers]] with [[polyvinyl acetate]]. They are typically used as coatings, [[adhesives]], and molding materials.<ref>{{cite web|url=http://www.merriam-webster.com/dictionary/formvar|title=Formvar|year=2014|publisher=Merriam-Webster, Inc.|website=Merriam-Webster.com|accessdate=10 July 2014}}</ref> "Formvar" used to be the registered [[trade name]] of the polyvinyl formal resin produced by [[Monsanto Chemical Company]] in [[St. Louis, Missouri]]. That manufacturing unit was sold and formvar is now distributed under the name "Vinylec".<ref name="SPI">{{cite web|url=http://www.2spi.com/catalog/submat/formvar-resins.shtml|title=SPI-Chem Vinylec (Formvar) Resins|publisher=Structure Probe, Inc.|date=10 July 2014|accessdate=10 July 2014|website=2SPI.com}}{{dead}}</ref> |
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==Applications== |
==Applications== |
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Formvar is used in many different applications, such as wire insulation, coatings for musical instruments, magnetic tape backing, and support films for [[electron microscopy]].<ref name="SPI" /> Formvar is also used as a main ingredient for special adhesives in structural applications such as the aircraft industry.<ref name="SPI app">{{cite web|url=http://www.2spi.com/catalog/submat/vinylec-applications.html|title=Vinylec |
Formvar is used in many different applications, such as wire insulation, coatings for musical instruments, magnetic tape backing, and support films for [[electron microscopy]].<ref name="SPI" /> Formvar is also used as a main ingredient for special adhesives in structural applications such as the aircraft industry.<ref name="SPI app">{{cite web|url=http://www.2spi.com/catalog/submat/vinylec-applications.html|title=Vinylec Resins|publisher=Structure Probe, Inc.|year=2000|accessdate=10 July 2014|website=2SPI.com}}{{dead}}</ref> |
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===Magnet wire=== |
===Magnet wire=== |
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===Transmission electron microscopy=== |
===Transmission electron microscopy=== |
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Most specimens used in [[transmission electron microscopy]] (TEM) need to be supported by a thin electron-transparent film to hold the sample in place. Formvar films are a common choice of film grid for TEM. Formvar is favored because it allows users to utilize grids with lower mesh rating.<ref>{{cite web|url=http://www.2spi.com/catalog/submat/sup_film3.shtml|title=SPI-Chem Formvar Resin for Electron Microscopy|publisher=Structure Probe, Inc.|date=10 July 2014|accessdate=10 July 2014|website=2SPI.com}}</ref> |
Most specimens used in [[transmission electron microscopy]] (TEM) need to be supported by a thin electron-transparent film to hold the sample in place. Formvar films are a common choice of film grid for TEM. Formvar is favored because it allows users to utilize grids with lower mesh rating.<ref>{{cite web|url=http://www.2spi.com/catalog/submat/sup_film3.shtml|title=SPI-Chem Formvar Resin for Electron Microscopy|publisher=Structure Probe, Inc.|date=10 July 2014|accessdate=10 July 2014|website=2SPI.com}}{{dead}}</ref> |
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==Physical characteristics== |
==Physical characteristics== |
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Revision as of 14:28, 25 April 2019
| Names | |
|---|---|
| IUPAC name
Polyvinyl formal
| |
| Identifiers | |
| ChemSpider |
|
| ECHA InfoCard | 100.109.921 |
CompTox Dashboard (EPA)
|
|
| Properties | |
| Appearance | White to straw colored powder |
| Density | 1.23 g/mL |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Formvar refers to any of several thermoplastic resins that are polyvinyl formals, which are polymers formed from polyvinyl alcohol and formaldehyde as copolymers with polyvinyl acetate. They are typically used as coatings, adhesives, and molding materials.[1] "Formvar" used to be the registered trade name of the polyvinyl formal resin produced by Monsanto Chemical Company in St. Louis, Missouri. That manufacturing unit was sold and formvar is now distributed under the name "Vinylec".[2]
Applications
Formvar is used in many different applications, such as wire insulation, coatings for musical instruments, magnetic tape backing, and support films for electron microscopy.[2] Formvar is also used as a main ingredient for special adhesives in structural applications such as the aircraft industry.[3]
Magnet wire
The major application of formvar resins is as electrical insulation for magnet wire. It is combined with other "wire enamels" which are then coated onto copper wire and cured in an oven to create a crosslinked film coating.[3]
Transmission electron microscopy
Most specimens used in transmission electron microscopy (TEM) need to be supported by a thin electron-transparent film to hold the sample in place. Formvar films are a common choice of film grid for TEM. Formvar is favored because it allows users to utilize grids with lower mesh rating.[4]
Physical characteristics
Formvar resin has a high softening point and strong electric insulation properties. It is also very flexible, water-insoluble, and resistant to abrasion. Formvar is also halogen free. Formvar resins are combustible and can cause dust explosions. For this reason exposure to heat, sparks, and flame should be avoided. Formvar is most commonly dissolved in ethylene dichloride, chloroform, and dioxane.[2]
References
- ^ "Formvar". Merriam-Webster.com. Merriam-Webster, Inc. 2014. Retrieved 10 July 2014.
- ^ a b c "SPI-Chem Vinylec (Formvar) Resins". 2SPI.com. Structure Probe, Inc. 10 July 2014. Retrieved 10 July 2014.[dead link]
- ^ a b "Vinylec Resins". 2SPI.com. Structure Probe, Inc. 2000. Retrieved 10 July 2014.[dead link]
- ^ "SPI-Chem Formvar Resin for Electron Microscopy". 2SPI.com. Structure Probe, Inc. 10 July 2014. Retrieved 10 July 2014.[dead link]