Polytetrafluoroethylene (PTFE) or teflon

Polytetrafluoroethylene (PTFE)

Polytetrafluoroethylene (trade name- Teflon), was accidentally discovered by Roy Plunkett (a Dupont chemist).
This is a polymer which has repeating chains of -(-CF₂-CF₂-)- in it.
It is an addition polymer of tetrafluoroethylene (CF₂= CF₂). It is obtained by heating tetrafloroethylene in a presence of catalyst at high pressure.

Polytetrafluoroethylene.
Polytetrafluoroethylene is produced by the free radical mechanism.
It is resistant to many chemicals.
It is weather and UV resistant.
It is non sticky.
It appears to be quite slippery.
It has outstanding performance at extreme temperatures.
It is used as a non-stick coating for cooking pans and utensils.
Teflon is also used in curling irons and straighteners.
Teflon is also coated on the iron to quicken the heating up process.
Teflon is also used as artificial limb and body parts.
Teflon tape or plumber's tape is a polytetrafluoroethylene film tape commonly used in plumbing. Teflon tape looks like a regular tape but it is not sticky at all. Next

Uses of Teflon.

Comments

Determination of molecular weight of polymers by viscosity method.

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Determination of molecular weight by Light scattering method.

Determination of molecular weight by Light scattering method. Due to big size macromolecules in solution, turbidity is produced. The light rays get scattered, when pass through macromolecule solution due to turbidity. The turbidity T is given by Where I₀ is the intensity of incident light. Iₜ is the intensity of transmitted light after passing through a solution of length l. In case of proteins or higher polymers the turbidity is small and is determine from the intensity of light scattered at 90° to the beam. This can be done by using a simple photometer as shown in figure below. Turbidity increase with increase in concentration as well as molecular weight. The Turbidity is related to molecular weight by the equation given by Debye. Hc/T=1/M+2Bc Where B is second virial coefficient and H is a constant. If we plot a graph between Hc/T vs c we get a straight line with intercept 1/M. Thus This curve was plotted by Zimm, so is called Zimm's Curve. Thus the c

Kinetics of copolymerisation and Composition of copolymer.

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Polymers

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