ChemWiki - User contributions [en]

Polytetrafluoroethylene

2006-12-08T16:54:58Z

Nrg05:

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} | Polytetrafluoroethylene
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[image:teflon.bmp]]
|-
! {{chembox header}} | General
|-
| Other Names
| Poly(tetrafluoroethylene) PTFE Teflon
|-
| Molecular Formula
| (CF2-CF2)n C2F4
|-
| Molar Mass
| 100.015612
|-
| Appearance and odour
| white powder white solid no odour
|-
| CAS Number
| 9002-84-0
|-
| {{chembox header}} | Mechanical properties
|-
| Tensile strength
| 2.500 - 4.000 (psi)
|-
| Elongation
| 200 - 400 (%)
|-
| Flexural Modulus
| 27.000 (psi)
|-
| Folding Endurance
| >106 ((MIT) cyles)
|-
| Coefficient of friction dynamic
| <0.1 (<3m/min)
|-
| {{chembox header}} | Thermal properties
|-
| Melting Point
| 327 (°C)
|-
| upper service temperature (20,000hr)
| 260 (°C)
|-
| Boiling Poing
| 400 °C
|-
| Limitibng oxygen index
| >95%
|-
| {{chembox header}} | Electrical properties
|-
| Dielectric constant
| 2.1 (MHz)
|-
| Dissipation factor
| 0.0001 (MHz)
|-
| Arc Resistnace
| >300 (sec)
|-
| Volume resistivity
| 1018 (Ohm-cm)
|-
| Surface resistivity
| 1018 (Ohm/sq cm)
|-
| {{chembox header}} | Other properties
|-
| Density
| 1.5 2
|-
| Refractive index
| 1.35 - 0
|-
| Solubility in water
| insoluble
|-
|}

==General==
'''Polytetrafluoroethylene''' ('''PTFE''') is a fluoropolymer and was serendipitously discovered in 1938 by Roy J. Plunkett. It entered the commercial market in 1946 and is now much better know as '''Teflon''', a brand name given by DuPont.

PTFE has the lowest known coefficiont of friction of any solid material, 0.1 or less. It is also very unreactive. This is why it is used as a non-stick coating for pans, general cookware, chemical containers and pipework. According to DuPont its melting point is 327 °C, but PTFE’s properties degrade above 260°C.
==Uses==
Some of PTFEs uses are to coat some hardened armourpiercing bullets. this is to reduce the wear on the inside of the firearms, when the bullets are fired.

Due to the fact that it has such a low coefficient of friction it is used a lot where parts slide over each other a lot, e.g. bearings, bushings, gears, slide plates, etc. The only problem here is that PTFE is quite susceptible to wear. Because PTFEs performance is so much better than for example acetal or nylon, mineral oils molybdenum disulfide are integrated into PTFEs structure to overcome the wear problem.

The most well know use for PTFE is for making nonstick pans. But it is also someimes used on carpets and fabrics, to make them extra stain resistant. Another big use for PTFE is in medicine. This is because bodies seldom reject it, so therefore it can be used for making artificial body parts.

[[image:P_25904990_1580696.jpg|thumb|non-stick frying pan]]
==Synthesis==
The complete synthesis actually takes the following steps:

CaF2 + H2SO4 --> CaSO4 + 2HF

CH4 + 3Cl2 --> CHCl3 + 3HCl

CHCl3 + 2HF --> CHClF2 + 2HCl

2CHClF2 --> CF2CF2 + 2HCl

PTFE is synthesised form the monomer tetrafluoroethylene, using a process known as free radical vinyl polymerization; under pressure and using free radical catalysts:

[[image:Ptfe04.gif]]

another way for PTFE to be produced is by directly substituting the hydrogen atoms in polyethylene with fluorine. This is done in the gas pahse at 20 °C:

[[image:Fluorination_of_polyethylene.gif]]
==References==
http://en.wikipedia.org/wiki/Polytetrafluoroethylene

http://physchem.ox.ac.uk/MSDS/PO/polytetrafluoroethylene.html

http://www.bocedwards.com/pdf/P120-09-025%20PTFE%20.pdf

http://www.teflon.com/

http://www.pslc.ws/mactest/ptfe.htm

http://www.sigmaaldrich.com/

http://www.chemexper.com/

Roberts, Royston M.; Serendipity: Accidental Discoveries in Science; John Wiley and Sons; New York; 1989.

http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/synthesis.html

Polytetrafluoroethylene

2006-12-08T16:46:33Z

Nrg05:

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} | Polytetrafluoroethylene
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[image:teflon.bmp]]
|-
! {{chembox header}} | General
|-
| Other Names
| Poly(tetrafluoroethylene) PTFE Teflon
|-
| Molecular Formula
| (CF2-CF2)n C2F4
|-
| Molar Mass
| 100.015612
|-
| Appearance and odour
| white powder white solid no odour
|-
| CAS Number
| 9002-84-0
|-
| {{chembox header}} | Mechanical properties
|-
| Tensile strength
| 2.500 - 4.000 (psi)
|-
| Elongation
| 200 - 400 (%)
|-
| Flexural Modulus
| 27.000 (psi)
|-
| Folding Endurance
| >106
|-
| Coefficient of friction dynamic
| <0.1 (<3m/min)
|-
| {{chembox header}} | Thermal properties
|-
| Melting Point
| 327 (°C)
|-
| upper service temperature (20,000hr)
| 260 (°C)
|-
| Boiling Poing
| 400 °C
|-
| Limitibng oxygen index
| >95%
|-
| {{chembox header}} | Electrical properties
|-
| Dielectric constant
| 2.1 (MHz)
|-
| Dissipation factor
| 0.0001 (MHz)
|-
| Arc Resistnace
| >300 (sec)
|-
| Volume resistivity
| 1018 (Ohm-cm)
|-
| Surface resistivity
| 1018 (Ohm/sq cm)
|-
| {{chembox header}} | Other properties
|-
| Density
| 1.5 2
|-
| Refractive index
| 1.35 - 0
|-
| Solubility in water
| insoluble
|-
|}

==General==
'''Polytetrafluoroethylene''' ('''PTFE''') is a fluoropolymer and was serendipitously discovered in 1938 by Roy J. Plunkett. It entered the commercial market in 1946 and is now much better know as '''Teflon''', a brand name given by DuPont.

PTFE has the lowest known coefficiont of friction of any solid material, 0.1 or less. It is also very unreactive. This is why it is used as a non-stick coating for pans, general cookware, chemical containers and pipework. According to DuPont its melting point is 327 °C, but PTFE’s properties degrade above 260°C.
==Uses==
Some of PTFEs uses are to coat some hardened armourpiercing bullets. this is to reduce the wear on the inside of the firearms, when the bullets are fired.

Due to the fact that it has such a low coefficient of friction it is used a lot where parts slide over each other a lot, e.g. bearings, bushings, gears, slide plates, etc. The only problem here is that PTFE is quite susceptible to wear. Because PTFEs performance is so much better than for example acetal or nylon, mineral oils molybdenum disulfide are integrated into PTFEs structure to overcome the wear problem.

The most well know use for PTFE is for making nonstick pans. But it is also someimes used on carpets and fabrics, to make them extra stain resistant. Another big use for PTFE is in medicine. This is because bodies seldom reject it, so therefore it can be used for making artificial body parts.

[[image:P_25904990_1580696.jpg|thumb|non-stick frying pan]]
==Synthesis==
The complete synthesis actually takes the following steps:

CaF2 + H2SO4 --> CaSO4 + 2HF

CH4 + 3Cl2 --> CHCl3 + 3HCl

CHCl3 + 2HF --> CHClF2 + 2HCl

2CHClF2 --> CF2CF2 + 2HCl

PTFE is synthesised form the monomer tetrafluoroethylene, using a process known as free radical vinyl polymerization; under pressure and using free radical catalysts:

[[image:Ptfe04.gif]]

another way for PTFE to be produced is by directly substituting the hydrogen atoms in polyethylene with fluorine. This is done in the gas pahse at 20 °C:

[[image:Fluorination_of_polyethylene.gif]]
==References==
http://en.wikipedia.org/wiki/Polytetrafluoroethylene

http://physchem.ox.ac.uk/MSDS/PO/polytetrafluoroethylene.html

http://www.bocedwards.com/pdf/P120-09-025%20PTFE%20.pdf

http://www.teflon.com/

http://www.pslc.ws/mactest/ptfe.htm

http://www.sigmaaldrich.com/

http://www.chemexper.com/

Roberts, Royston M.; Serendipity: Accidental Discoveries in Science; John Wiley and Sons; New York; 1989.

http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/synthesis.html

File:Fluorination of polyethylene.gif

2006-12-08T16:45:45Z

Nrg05:

Polytetrafluoroethylene

2006-12-08T16:45:11Z

Nrg05:

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} | Polytetrafluoroethylene
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[image:teflon.bmp]]
|-
! {{chembox header}} | General
|-
| Other Names
| Poly(tetrafluoroethylene) PTFE Teflon
|-
| Molecular Formula
| (CF2-CF2)n C2F4
|-
| Molar Mass
| 100.015612
|-
| Appearance and odour
| white powder white solid no odour
|-
| CAS Number
| 9002-84-0
|-
| {{chembox header}} | Mechanical properties
|-
| Tensile strength
| 2.500 - 4.000 (psi)
|-
| Elongation
| 200 - 400 (%)
|-
| Flexural Modulus
| 27.000 (psi)
|-
| Folding Endurance
| >106
|-
| Coefficient of friction dynamic
| <0.1 (<3m/min)
|-
| {{chembox header}} | Thermal properties
|-
| Melting Point
| 327 (°C)
|-
| upper service temperature (20,000hr)
| 260 (°C)
|-
| Boiling Poing
| 400 °C
|-
| Limitibng oxygen index
| >95%
|-
| {{chembox header}} | Electrical properties
|-
| Dielectric constant
| 2.1 (MHz)
|-
| Dissipation factor
| 0.0001 (MHz)
|-
| Arc Resistnace
| >300 (sec)
|-
| Volume resistivity
| 1018 (Ohm-cm)
|-
| Surface resistivity
| 1018 (Ohm/sq cm)
|-
| {{chembox header}} | Other properties
|-
| Density
| 1.5 2
|-
| Refractive index
| 1.35 - 0
|-
| Solubility in water
| insoluble
|-
|}

==General==
'''Polytetrafluoroethylene''' ('''PTFE''') is a fluoropolymer and was serendipitously discovered in 1938 by Roy J. Plunkett. It entered the commercial market in 1946 and is now much better know as '''Teflon''', a brand name given by DuPont.

PTFE has the lowest known coefficiont of friction of any solid material, 0.1 or less. It is also very unreactive. This is why it is used as a non-stick coating for pans, general cookware, chemical containers and pipework. According to DuPont its melting point is 327 °C, but PTFE’s properties degrade above 260°C.
==Uses==
Some of PTFEs uses are to coat some hardened armourpiercing bullets. this is to reduce the wear on the inside of the firearms, when the bullets are fired.

Due to the fact that it has such a low coefficient of friction it is used a lot where parts slide over each other a lot, e.g. bearings, bushings, gears, slide plates, etc. The only problem here is that PTFE is quite susceptible to wear. Because PTFEs performance is so much better than for example acetal or nylon, mineral oils molybdenum disulfide are integrated into PTFEs structure to overcome the wear problem.

The most well know use for PTFE is for making nonstick pans. But it is also someimes used on carpets and fabrics, to make them extra stain resistant. Another big use for PTFE is in medicine. This is because bodies seldom reject it, so therefore it can be used for making artificial body parts.

[[image:P_25904990_1580696.jpg|thumb|non-stick frying pan]]
==Synthesis==
The complete synthesis actually takes the following steps:

CaF2 + H2SO4 --> CaSO4 + 2HF

CH4 + 3Cl2 --> CHCl3 + 3HCl

CHCl3 + 2HF --> CHClF2 + 2HCl

2CHClF2 --> CF2CF2 + 2HCl

PTFE is synthesised form the monomer tetrafluoroethylene, using a process known as free radical vinyl polymerization; under pressure and using free radical catalysts.

[[image:Ptfe04.gif]]

another way for PTFE to be produced is by directly substituting the hydrogen atoms in polyethylene with fluorine. This is done in the gas pahse at 20 °C.

[[image

==References==
http://en.wikipedia.org/wiki/Polytetrafluoroethylene

http://physchem.ox.ac.uk/MSDS/PO/polytetrafluoroethylene.html

http://www.bocedwards.com/pdf/P120-09-025%20PTFE%20.pdf

http://www.teflon.com/

http://www.pslc.ws/mactest/ptfe.htm

http://www.sigmaaldrich.com/

http://www.chemexper.com/

Roberts, Royston M.; Serendipity: Accidental Discoveries in Science; John Wiley and Sons; New York; 1989.

http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/synthesis.html

Polytetrafluoroethylene

2006-12-08T16:41:33Z

Nrg05:

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} | Polytetrafluoroethylene
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[image:teflon.bmp]]
|-
! {{chembox header}} | General
|-
| Other Names
| Poly(tetrafluoroethylene) PTFE Teflon
|-
| Molecular Formula
| (CF2-CF2)n C2F4
|-
| Molar Mass
| 100.015612
|-
| Appearance and odour
| white powder white solid no odour
|-
| CAS Number
| 9002-84-0
|-
| {{chembox header}} | Mechanical properties
|-
| Tensile strength
| 2.500 - 4.000 (psi)
|-
| Elongation
| 200 - 400 (%)
|-
| Flexural Modulus
| 27.000 (psi)
|-
| Folding Endurance
| >106
|-
| Coefficient of friction dynamic
| <0.1 (<3m/min)
|-
| {{chembox header}} | Thermal properties
|-
| Melting Point
| 327 (°C)
|-
| upper service temperature (20,000hr)
| 260 (°C)
|-
| Boiling Poing
| 400 °C
|-
| Limitibng oxygen index
| >95%
|-
| {{chembox header}} | Electrical properties
|-
| Dielectric constant
| 2.1 (MHz)
|-
| Dissipation factor
| 0.0001 (MHz)
|-
| Arc Resistnace
| >300 (sec)
|-
| Volume resistivity
| 1018 (Ohm-cm)
|-
| Surface resistivity
| 1018 (Ohm/sq cm)
|-
| {{chembox header}} | Other properties
|-
| Density
| 1.5 2
|-
| Refractive index
| 1.35 - 0
|-
| Solubility in water
| insoluble
|-
|}

==General==
'''Polytetrafluoroethylene''' ('''PTFE''') is a fluoropolymer and was serendipitously discovered in 1938 by Roy J. Plunkett. It entered the commercial market in 1946 and is now much better know as '''Teflon''', a brand name given by DuPont.

PTFE has the lowest known coefficiont of friction of any solid material, 0.1 or less. It is also very unreactive. This is why it is used as a non-stick coating for pans, general cookware, chemical containers and pipework. According to DuPont its melting point is 327 °C, but PTFE’s properties degrade above 260°C.
==Uses==
Some of PTFEs uses are to coat some hardened armourpiercing bullets. this is to reduce the wear on the inside of the firearms, when the bullets are fired.

Due to the fact that it has such a low coefficient of friction it is used a lot where parts slide over each other a lot, e.g. bearings, bushings, gears, slide plates, etc. The only problem here is that PTFE is quite susceptible to wear. Because PTFEs performance is so much better than for example acetal or nylon, mineral oils molybdenum disulfide are integrated into PTFEs structure to overcome the wear problem.

The most well know use for PTFE is for making nonstick pans. But it is also someimes used on carpets and fabrics, to make them extra stain resistant. Another big use for PTFE is in medicine. This is because bodies seldom reject it, so therefore it can be used for making artificial body parts.

[[image:P_25904990_1580696.jpg|thumb|non-stick frying pan]]
==Synthesis==
The complete synthesis actually takes the following steps:

CaF2 + H2SO4 --> CaSO4 + 2HF

CH4 + 3Cl2 --> CHCl3 + 3HCl

CHCl3 + 2HF --> CHClF2 + 2HCl

2CHClF2 --> CF2CF2 + 2HCl

PTFE is synthesised form the monomer tetrafluoroethylene, using a process known as free radical vinyl polymerization; under pressure and using free radical catalysts.

[[image:Ptfe04.gif]]

==References==
http://en.wikipedia.org/wiki/Polytetrafluoroethylene

http://physchem.ox.ac.uk/MSDS/PO/polytetrafluoroethylene.html

http://www.bocedwards.com/pdf/P120-09-025%20PTFE%20.pdf

http://www.teflon.com/

http://www.pslc.ws/mactest/ptfe.htm

http://www.sigmaaldrich.com/

http://www.chemexper.com/

Roberts, Royston M.; Serendipity: Accidental Discoveries in Science; John Wiley and Sons; New York; 1989.

File:Ptfe04.gif

2006-12-08T16:36:05Z

Nrg05:

Polytetrafluoroethylene

2006-12-08T16:35:45Z

Nrg05:

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} | Polytetrafluoroethylene
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[image:teflon.bmp]]
|-
! {{chembox header}} | General
|-
| Other Names
| Poly(tetrafluoroethylene) PTFE Teflon
|-
| Molecular Formula
| (CF2-CF2)n C2F4
|-
| Molar Mass
| 100.015612
|-
| Appearance and odour
| white powder white solid no odour
|-
| CAS Number
| 9002-84-0
|-
| {{chembox header}} | Mechanical properties
|-
| Tensile strength
| 2.500 - 4.000 (psi)
|-
| Elongation
| 200 - 400 (%)
|-
| Flexural Modulus
| 27.000 (psi)
|-
| Folding Endurance
| >106
|-
| Coefficient of friction dynamic
| <0.1 (<3m/min)
|-
| {{chembox header}} | Thermal properties
|-
| Melting Point
| 327 (°C)
|-
| upper service temperature (20,000hr)
| 260 (°C)
|-
| Boiling Poing
| 400 °C
|-
| Limitibng oxygen index
| >95%
|-
| {{chembox header}} | Electrical properties
|-
| Dielectric constant
| 2.1 (MHz)
|-
| Dissipation factor
| 0.0001 (MHz)
|-
| Arc Resistnace
| >300 (sec)
|-
| Volume resistivity
| 1018 (Ohm-cm)
|-
| Surface resistivity
| 1018 (Ohm/sq cm)
|-
| {{chembox header}} | Other properties
|-
| Density
| 1.5 2
|-
| Refractive index
| 1.35 - 0
|-
| Solubility in water
| insoluble
|-
|}

==General==
'''Polytetrafluoroethylene''' ('''PTFE''') is a fluoropolymer and was serendipitously discovered in 1938 by Roy J. Plunkett. It entered the commercial market in 1946 and is now much better know as '''Teflon''', a brand name given by DuPont.

PTFE has the lowest known coefficiont of friction of any solid material, 0.1 or less. It is also very unreactive. This is why it is used as a non-stick coating for pans, general cookware, chemical containers and pipework. According to DuPont its melting point is 327 °C, but PTFE’s properties degrade above 260°C.
==Uses==
Some of PTFEs uses are to coat some hardened armourpiercing bullets. this is to reduce the wear on the inside of the firearms, when the bullets are fired.

Due to the fact that it has such a low coefficient of friction it is used a lot where parts slide over each other a lot, e.g. bearings, bushings, gears, slide plates, etc. The only problem here is that PTFE is quite susceptible to wear. Because PTFEs performance is so much better than for example acetal or nylon, mineral oils molybdenum disulfide are integrated into PTFEs structure to overcome the wear problem.

The most well know use for PTFE is for making nonstick pans. But it is also someimes used on carpets and fabrics, to make them extra stain resistant. Another big use for PTFE is in medicine. This is because bodies seldom reject it, so therefore it can be used for making artificial body parts.

[[image:P_25904990_1580696.jpg|thumb|non-stick frying pan]]
==Synthesis==
PTFE is synthesised form the monomer tetrafluoroethylene, using a process known as free radical vinyl polymerization; under pressure and using free radical catalysts.

-->

==References==
http://en.wikipedia.org/wiki/Polytetrafluoroethylene

http://physchem.ox.ac.uk/MSDS/PO/polytetrafluoroethylene.html

http://www.bocedwards.com/pdf/P120-09-025%20PTFE%20.pdf

http://www.teflon.com/

http://www.pslc.ws/mactest/ptfe.htm

http://www.sigmaaldrich.com/

http://www.chemexper.com/

Roberts, Royston M.; Serendipity: Accidental Discoveries in Science; John Wiley and Sons; New York; 1989.

Polytetrafluoroethylene

2006-12-08T16:34:01Z

Nrg05:

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} | Polytetrafluoroethylene
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[image:teflon.bmp]]
|-
! {{chembox header}} | General
|-
| Other Names
| Poly(tetrafluoroethylene) PTFE Teflon
|-
| Molecular Formula
| (CF2-CF2)n C2F4
|-
| Molar Mass
| 100.015612
|-
| Appearance and odour
| white powder white solid no odour
|-
| CAS Number
| 9002-84-0
|-
| {{chembox header}} | Mechanical properties
|-
| Tensile strength
| 2.500 - 4.000 (psi)
|-
| Elongation
| 200 - 400 (%)
|-
| Flexural Modulus
| 27.000 (psi)
|-
| Folding Endurance
| >106
|-
| Coefficient of friction dynamic
| <0.1 (<3m/min)
|-
| {{chembox header}} | Thermal properties
|-
| Melting Point
| 327 (°C)
|-
| upper service temperature (20,000hr)
| 260 (°C)
|-
| Boiling Poing
| 400 °C
|-
| Limitibng oxygen index
| >95%
|-
| {{chembox header}} | Electrical properties
|-
| Dielectric constant
| 2.1 (MHz)
|-
| Dissipation factor
| 0.0001 (MHz)
|-
| Arc Resistnace
| >300 (sec)
|-
| Volume resistivity
| 1018 (Ohm-cm)
|-
| Surface resistivity
| 1018 (Ohm/sq cm)
|-
| {{chembox header}} | Other properties
|-
| Density
| 1.5 2
|-
| Refractive index
| 1.35 - 0
|-
| Solubility in water
| insoluble
|-
|}

==General==
'''Polytetrafluoroethylene''' ('''PTFE''') is a fluoropolymer and was serendipitously discovered in 1938 by Roy J. Plunkett. It entered the commercial market in 1946 and is now much better know as '''Teflon''', a brand name given by DuPont.

PTFE has the lowest known coefficiont of friction of any solid material, 0.1 or less. It is also very unreactive. This is why it is used as a non-stick coating for pans, general cookware, chemical containers and pipework. According to DuPont its melting point is 327 °C, but PTFE’s properties degrade above 260°C.
==Uses==
Some of PTFEs uses are to coat some hardened armourpiercing bullets. this is to reduce the wear on the inside of the firearms, when the bullets are fired.

Due to the fact that it has such a low coefficient of friction it is used a lot where parts slide over each other a lot, e.g. bearings, bushings, gears, slide plates, etc. The only problem here is that PTFE is quite susceptible to wear. Because PTFEs performance is so much better than for example acetal or nylon, mineral oils molybdenum disulfide are integrated into PTFEs structure to overcome the wear problem.

The most well know use for PTFE is for making nonstick pans. But it is also someimes used on carpets and fabrics, to make them extra stain resistant. Another big use for PTFE is in medicine. This is because bodies seldom reject it, so therefore it can be used for making artificial body parts.

[[image:P_25904990_1580696.jpg|thumb|non-stick frying pan]]
==Synthesis==
PTFE is synthesised form the monomer tetrafluoroethylene, using a process known as free radical vinyl polymerization.

-->

==References==
http://en.wikipedia.org/wiki/Polytetrafluoroethylene

http://physchem.ox.ac.uk/MSDS/PO/polytetrafluoroethylene.html

http://www.bocedwards.com/pdf/P120-09-025%20PTFE%20.pdf

http://www.teflon.com/

http://www.pslc.ws/mactest/ptfe.htm

http://www.sigmaaldrich.com/

http://www.chemexper.com/

Roberts, Royston M.; Serendipity: Accidental Discoveries in Science; John Wiley and Sons; New York; 1989.

Polytetrafluoroethylene

2006-12-08T15:30:41Z

Nrg05:

Polytetrafluoroethylene

2006-12-08T15:26:35Z

Nrg05:

Polytetrafluoroethylene

2006-12-08T15:19:01Z

Nrg05:

File:P 25904990 1580696.jpg

2006-12-08T15:17:31Z

Nrg05:

Polytetrafluoroethylene

2006-12-08T15:08:26Z

Nrg05:

Polytetrafluoroethylene

2006-12-08T14:40:24Z

Nrg05:

Polytetrafluoroethylene

2006-12-08T12:18:21Z

Nrg05:

Polytetrafluoroethylene

2006-12-08T12:18:01Z

Nrg05:

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} | Polytetrafluoroethylene
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[image:teflon.bmp]]
|-
! {{chembox header}} | General
|-
| Other Names
| Poly(tetrafluoroethylene) PTFE Teflon
|-
| Molecular Formula
| (CF2-CF2)n C2F4
|-
| Molar Mass
| 100.015612
|-
| CAS Number
| 9002-84-0
|-
| {{chembox header}} | Properties
|-
| Melting Point
| 327 °C
|-
| Boiling Poing
| 400 °C
|-
| Appearance and odour
| white powder white solid no odour
|-
| Coefficient of friction
| <0.1
|-
| Density
| 1.5 2
|-
| Refractive index
| 1.35 - 0
|-
| Solubility in water
| insoluble
|-
| Specific Gravity
| 0.3 - 0.6
|-
|}

==General==
'''Polytetrafluoroethylene''' ('''PTFE''') is a fluoropolymer and was discovered in 1938 by Roy J. Plunkett. It entered the commercial market in 1946 and is now much better know as '''Teflon''', a brand name given by DuPont.

PTFE has the lowest known coefficiont of friction of any solid material, 0.1 or less. It is also very unreactive. This is why it is used as a non-stick coating for pans, general cookware, chemical containers and pipework. According to DuPont its melting point is 327 °C, but PTFE’s properties degrade above 260°C.
==Properties and applications==
Some of PTFEs uses are to coat some

Amongst many other industrial applications, PTFE is used to coat certain types of hardened, armour-piercing bullets, so as to reduce the amount of wear on the firearm's rifling. These are often mistakenly referred to as "cop-killer" bullets by virtue of PTFE's supposed ability to ease a bullet's passage through body armour. Any armour-piercing effect is, however, purely a function of the bullet's velocity and rigidity rather than a property of PTFE.

PTFE has excellent dielectric properties. This is especially true at high radio frequencies, making it eminently suitable for use as an insulator in cables and connector assemblies and as a material for printed circuit boards used at microwave frequencies. Combined with its high melting temperature, this makes it the material of choice as a high performance substitute for the weaker and more meltable polyethylene that is commonly used in low-cost applications. Its extremely high bulk resistivity makes it an ideal material for fabricating long life electrets, useful devices that are the electrostatic analogues of magnets.

Due to its low friction, it is used for applications where sliding action of parts is needed: bearings, bushings, gears, slide plates, etc. In these applications it performs significantly better than nylon and acetal; it is comparable with ultra high molecular weight polyethylene (UHMWPE), although UHMWPE is more resistant to wear than Teflon. For these applications, versions of teflon with mineral oil or molybdenum disulfide embedded as additional lubricants in its matrix are being manufactured.

Because of its chemical inertness, PTFE cannot be cross-linked like an elastomer. Therefore it has no "memory", and is subject to creep (also known as cold flow and compression set). This can be both good and bad. A little bit of creep allows PTFE seals to conform to mating surfaces better than most other plastic seals. Too much creep, however, and the seal is compromised. Compounding fillers are used to control unwanted creep, as well as to improve wear, friction, and other properties.

Gore-Tex is a material incorporating Teflon membrane with micropores. The roof of the Hubert H. Humphrey Metrodome in Minneapolis is the largest application of Teflon on Earth, using 20 acres of the material in a double-layered white dome, made with PTFE-coated fiberglass, that gives the stadium its distinctive appearance.

It also, due to its flexibilty and bio-compatibility is used in body piercing, such as in a Corset piercing.

Powdered PTFE is used in pyrotechnic compositions as oxidizer together with powdered metals such as aluminum and magnesium (see Magnesium/Teflon/Viton). Upon ignition these mixtures form carbonaceous soot and the corresponding metal fluoride and release large amounts of heat. Hence they are use as infrared decoy flares and igniters for solid fuel rocket propellants.[4]

==Uses==

==References==

Polytetrafluoroethylene

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Polytetrafluoroethylene

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Polytetrafluoroethylene

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Polytetrafluoroethylene

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Polytetrafluoroethylene

2006-12-07T18:42:14Z

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Polytetrafluoroethylene

2006-12-07T18:19:45Z

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File:Teflon.bmp

2006-12-07T18:17:11Z

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File:Teflon.cdx

2006-12-07T18:13:52Z

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Polytetrafluoroethylene

2006-12-07T18:04:04Z

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{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} | Polytetrafluoroethylene
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[]]
|-
! {{chembox header}} | General
|-
| Systematic name
|
|-
| Other Names
| PTFE Teflon<br
|-
| Molecular Formula
|
|-
| Molar Mass
|
|-
| CAS Number
|
|-
| {{chembox header}} | Properties
|-
| Melting Point
|
|-
| Boiling Poing
|
|-
| Appearance
|
|-
| Vapor Density
|
|-
| Vapour Pressure
|
|-
| Auto-ignition Temperature
|
|-
|}

==General==
Polytetrafluoroethylene (PTFE) is a fluoropolymer and was discovered in 1938 by Roy J. Plunkett. It entered the commercial market in 1946 and is now much better know as Teflon, a brand name given by DuPont.

==Hazards==

==Uses==

==References==

Polytetrafluoroethylene

2006-12-07T18:03:40Z

Nrg05:

Polytetrafluoroethylene

2006-12-07T18:03:11Z

Nrg05:

Polytetrafluoroethylene

2006-12-07T18:02:47Z

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