Teflon© A.k.a.: Polytetrafluoroethylene, PTFE Eric Alberigi, Michael Gammon, James Morison

History of Teflon © Discovered on April 6, 1938 by a DuPont chemist Dr. Roy J. Plunkett 1 Discovered on April 6, 1938 by a DuPont chemist Dr. Roy J. Plunkett 1

Chemistry of Teflon© Consists of a chain of carbon atoms completely surrounded by fluorine atoms. Consists of a chain of carbon atoms completely surrounded by fluorine atoms. Fluorine atoms shield the carbon chain due to strong bonds between them. Fluorine atoms shield the carbon chain due to strong bonds between them. Starts life out as a vinyl monomer. Starts life out as a vinyl monomer. Undergoes free radical vinyl Undergoes free radical vinyl polymerization turning into polytetrafluorethylene. 6. polymerization turning into polytetrafluorethylene. 6.

Properties of Teflon© Tensile Strength: MPa Tensile Strength: MPa Melting Point: 327 °C Melting Point: 327 °C Particle Size: micron 8. Particle Size: micron 8. Coefficient of Friction Coefficient of Friction Static: Kinetic:

Properties of Teflon© Continued Inert to virtually all chemicals. Inert to virtually all chemicals. Lowest coefficient of friction of known materials. Lowest coefficient of friction of known materials. Lowest dielectric constant of any known plastic ( ). Lowest dielectric constant of any known plastic ( ). Easy to mold and spin cast. Easy to mold and spin cast. Resists moisture. 1. Resists moisture. 1.

Properties of Teflon© Continued Teflon has the lowest dielectric constant of any known plastic, ranging from , and can maintain this constant at extremely high frequencies (GHz) which is good for telecommunication devises. 1. It has one of the highest dielectric strengths which means it can withstand a very high voltage without discharging. 10. Teflon has the lowest dielectric constant of any known plastic, ranging from , and can maintain this constant at extremely high frequencies (GHz) which is good for telecommunication devises. 1. It has one of the highest dielectric strengths which means it can withstand a very high voltage without discharging. 10. Teflon has a high chemical resistance to everything but molten alkali metals and fluorocarbon oils. 3. Teflon has a high chemical resistance to everything but molten alkali metals and fluorocarbon oils. 3. MaterialDielectric ConstantDielectric Strength (10^6 V/m) Air Rubber6.712 Nylon3.414 Water80n/a Pyrex5.614 Fused Quartz3.788 Teflon

Applications of Teflon © Teflon coated cookware Teflon coated cookware Teflon impregnated clothing Teflon impregnated clothing Capacitors Capacitors Teflon infused oils Teflon infused oils Teflon tubing, specifically for chemistry applications Teflon tubing, specifically for chemistry applications Teflon coated bearings Teflon coated bearings Teflon bench laminates Teflon bench laminates Useful as a plastic substitute when harsh chemicals are involved Useful as a plastic substitute when harsh chemicals are involved

Teflon © Friction Test This test was used to find the static and kinetic coefficient of friction of wood onto Teflon and other materials. Force probe was connected to a block and was pulled at a constant velocity. Force probe was connected to a block and was pulled at a constant velocity. Force vs. Time was then graphed. Force vs. Time was then graphed.

Teflon © Friction Test Material μkμkμkμk μsμsμsμsMaterial μkμkμkμk μsμsμsμs Teflon Plastic Teflon Plastic Wood Metal Wood Metal Increase in Friction Force  Wood: Dynamic 73 % Static 108 %  Plastic: Dynamic 55 % Static 63%

Teflon © Friction Test

Why does Teflon have such a low coefficient of friction and is so non-reactive? Why does Teflon have such a low coefficient of friction and is so non-reactive? Both of these attributes derive from the same property. When a foreign substance touches the PTFE, it does not want to stick to it because the fluorine makes such a tight bond with the carbon the fluorine will repel the molecule trying to touch it, for this reason, Teflon has a very low coefficient of friction and is also non-reactive. Both of these attributes derive from the same property. When a foreign substance touches the PTFE, it does not want to stick to it because the fluorine makes such a tight bond with the carbon the fluorine will repel the molecule trying to touch it, for this reason, Teflon has a very low coefficient of friction and is also non-reactive.

Bending Test 5. This test was performed to determine the Modulus of elasticity of PTFE. This test was performed to determine the Modulus of elasticity of PTFE. Teflon plate was placed on two stands and a load was placed onto the Teflon. The deflection of the board was then measured. Teflon plate was placed on two stands and a load was placed onto the Teflon. The deflection of the board was then measured.

Bending Test In order to determine the modulus of elasticity, we have to factor in the size of our Teflon plate, to do this, we first find second moment of inertia: I = WH3/12 where W is the width, H is the height of our sample. In order to determine the modulus of elasticity, we have to factor in the size of our Teflon plate, to do this, we first find second moment of inertia: I = WH3/12 where W is the width, H is the height of our sample. Next, we used the formula d = WL3/48EI, where d is the displacement, W is the load, L is the distance between the supports, E is the modulus of elasticity, and I is the second moment of inertia. 5. Next, we used the formula d = WL3/48EI, where d is the displacement, W is the load, L is the distance between the supports, E is the modulus of elasticity, and I is the second moment of inertia. 5.

Bending Test Results

We determined the modulus of elasticity to be 0.82 GPa from the data taken above. This seems to be correct because it is relatively low compared to metals, this means that the Teflon is not as stiff as metals that we have studied. We determined the modulus of elasticity to be 0.82 GPa from the data taken above. This seems to be correct because it is relatively low compared to metals, this means that the Teflon is not as stiff as metals that we have studied. Material Modulus of Elasticity (Gpa) Aluminum25 Magnesium17 Steel83 Tungsten160 Teflon

Question Page Question: If Teflon doesn’t stick to anything, how does it stick to my frying pan? Question: If Teflon doesn’t stick to anything, how does it stick to my frying pan? Question: What National Monument uses Teflon? Question: What National Monument uses Teflon? Question: What are some good applications of Teflon? Question: What are some good applications of Teflon?

Answer Page Answer 1: The pan is bead-blasted and a primer is applied to the pan, then the Teflon is imbedded into the primer. Answer 1: The pan is bead-blasted and a primer is applied to the pan, then the Teflon is imbedded into the primer. Answer 2: The Statue of Liberty has a Teflon coated steel structure so it does not ruin the copper skin. Answer 2: The Statue of Liberty has a Teflon coated steel structure so it does not ruin the copper skin.

Conclusion Teflon's properties of being non-reactive and having an extremely low coefficient of friction gives it a wide variety of uses. From Teflon coated bearings and windshield wipers, to stain resistant Teflon impregnated pants, Teflon helps improves our lives in many ways. Teflon's properties of being non-reactive and having an extremely low coefficient of friction gives it a wide variety of uses. From Teflon coated bearings and windshield wipers, to stain resistant Teflon impregnated pants, Teflon helps improves our lives in many ways. It could be possibly the greatest material ever invented (by mistake) by man. It could be possibly the greatest material ever invented (by mistake) by man.

References www2.rpa.net/~kras1474/tefuses.html Callister, William D. Materials Science and Engineering an Introduction. Hoboken, NJ: John Wiley & Sons Inc., Serway, Raymond A., and John W. Jewett. Physics for Scientists and Engineers. Belmont, CA: Thomson Brooks/Cole,