Difference between revisions of "Pentane"

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(Created page with "PTFE seal tape. '''Polytetrafluoroethylene''' or '''PTFE''' or '''Teflon''' is a synthetic fluoropolymer of tetrafluoroethylene,...")
 
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[[File:PTFE_thread_seal_tape.jpg|thumb|300px|PTFE seal tape.]]
 
[[File:PTFE_thread_seal_tape.jpg|thumb|300px|PTFE seal tape.]]
'''Polytetrafluoroethylene''' or '''PTFE''' or '''Teflon''' is a synthetic fluoropolymer of tetrafluoroethylene, well known for its chemical inertness and very low coefficient of friction.
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'''Pentane''' is an organic compound, an alkane with 5 carbon atoms. It is composed of three isomers, '''n-pentane''', [[isopentane]] (or methylbutane) and [[neopentane]]. While the term "pentane" may refer to any of the isomers, the IUPAC nomenclature specifies that the term must only be used for the n isomer.
  
 
==Properties==
 
==Properties==
 
===Chemical===
 
===Chemical===
PTFE is extremely resistant to chemical attacks, being only affected by molten alkali and strong fluorinating agents such as cobalt(III) fluoride and xenon difluoride. Teflon strips can burn in air, but it's most likely that the pyrolysis products are the one that catch fire.
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Pentane, like other hydrocarbons, will burn in air when ignited by an open flame to release carbon dioxide and water vapor.
  
 
===Physical===
 
===Physical===
PTFE is a white solid at room temperature, with a melting point of 327 °C. Its density is 2.2 g/cm<sup>3</sup>. PTFE maintains mechanical properties down to temperatures of 5 K (−268.15 °C), and has good flexibility at temperatures above −79 °C. Teflon materials however are susceptible to creep. When melted, PTFE has the consistency of paste, so items can only be cast via injection.
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Pentane is a colorless liquid hydrocarbon, with a characteristic smell. It is insoluble in water, but miscible with other organic solvents. It has a density of 0.621 g/cm<sup>3</sup>, meaning it's lighter than water. It boils at 36°C and melts at -130°C.
  
 
==Availability==
 
==Availability==
PTFE is cheaply available as thread seal tapes. Many lab items, such as stoppers, gaskets, sleeves, [[magnetic stirrers]] are made of it and can be easily procured online. However, items made of PTFE are expensive, as PTFE cannot be molded like the more common type of plastics.
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Pentane can be purchased form chemical suppliers. Certain pesticides contain pentane.
  
 
==Preparation==
 
==Preparation==
PTFE is made via polymerization of tetrafluoroethylene. This process is difficult and expensive for the amateur chemist.
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Pentane can be prepared by reducing pentane derivates.
  
 
==Projects==
 
==Projects==
*[[Magnesium]]/PTFE flash powder
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*Extraction (solvent)
*[[Ytterbium]]/PTFE emerald green composition with high IR output
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*Phthalic and maleic anhydride synthesis
  
 
==Handling==
 
==Handling==
 
===Safety===
 
===Safety===
PTFE, being chemically inert, is non-toxic. Its pyrolysis is detectable at 200 °C, giving off fluorocarbon gases, that in large quantities can be dangerous for humans and are very toxic to wildlife, such as birds.
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Pentane evaporates very fast and the vapors are hazardous if inhaled, work should be performed in a fumehood or outside. If pentane is inhaled in large amounts, further exposure should be limited and one should seek fresh air.
  
 
===Storage===
 
===Storage===
No special storage is required.
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Due to its low boiling point, pentane should be stored in closed glass bottles, at constant temperature, away from any source of heat, even small ones. If it's stored at low temperatures, and then brought at room temperatures or slightly higher, pressure will build up in the bottle from the vapors and the bottle can explode. It is mandatory to open the bottle from time to time, to release the pressure.
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Commercial pentane contains small amounts of inhibitors, that prevent its degradation, over long periods of time. They can be removed by distillation, as their boiling point is much higher than that of pentane.
  
 
===Disposal===
 
===Disposal===
Being chemically inert, PTFE poses hazard to the environment, as it cannot be digested by wildlife.
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Pentane can be safely burned, as it theoretically should not generate any toxic byproducts. However, like other hydrocarbons, carbon monoxide can be formed so this should not be performed indoors.
  
 
==References==
 
==References==
 
<references/>
 
<references/>
 
===Relevant Sciencemadness threads===
 
===Relevant Sciencemadness threads===

Revision as of 15:37, 16 June 2015

PTFE seal tape.

Pentane is an organic compound, an alkane with 5 carbon atoms. It is composed of three isomers, n-pentane, isopentane (or methylbutane) and neopentane. While the term "pentane" may refer to any of the isomers, the IUPAC nomenclature specifies that the term must only be used for the n isomer.

Properties

Chemical

Pentane, like other hydrocarbons, will burn in air when ignited by an open flame to release carbon dioxide and water vapor.

Physical

Pentane is a colorless liquid hydrocarbon, with a characteristic smell. It is insoluble in water, but miscible with other organic solvents. It has a density of 0.621 g/cm3, meaning it's lighter than water. It boils at 36°C and melts at -130°C.

Availability

Pentane can be purchased form chemical suppliers. Certain pesticides contain pentane.

Preparation

Pentane can be prepared by reducing pentane derivates.

Projects

  • Extraction (solvent)
  • Phthalic and maleic anhydride synthesis

Handling

Safety

Pentane evaporates very fast and the vapors are hazardous if inhaled, work should be performed in a fumehood or outside. If pentane is inhaled in large amounts, further exposure should be limited and one should seek fresh air.

Storage

Due to its low boiling point, pentane should be stored in closed glass bottles, at constant temperature, away from any source of heat, even small ones. If it's stored at low temperatures, and then brought at room temperatures or slightly higher, pressure will build up in the bottle from the vapors and the bottle can explode. It is mandatory to open the bottle from time to time, to release the pressure.

Commercial pentane contains small amounts of inhibitors, that prevent its degradation, over long periods of time. They can be removed by distillation, as their boiling point is much higher than that of pentane.

Disposal

Pentane can be safely burned, as it theoretically should not generate any toxic byproducts. However, like other hydrocarbons, carbon monoxide can be formed so this should not be performed indoors.

References

Relevant Sciencemadness threads