This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Explain why a rubber washer stops sealing tightly after several years. What will be an ideal ... (Read 96 times)

dbose

  • Hero Member
  • *****
  • Posts: 597
on: Aug 19, 2018
Explain why a rubber washer stops sealing tightly after several years.
 
  What will be an ideal response?

Question 2

Why would fluorocarbon elastomers be so effective in resisting solvents?
 
  What will be an ideal response?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

srodz

  • Sr. Member
  • ****
  • Posts: 333
Reply #1 on: Aug 19, 2018
Answer to Question 1

Over time the rubber is going to continue to crosslink and become harder which will not be as compliant with the other surface. This will also cause it to become more brittle and eventually break. It could also degrade.

Answer to Question 2

As with fluorocarbon molding resins, the presence of fluorine in the elastomer reduces all chemical activity, including solvation effects. This occurs because of the strength of the carbon-fluorine bond and the tightness with which the fluorine electrons are held. These tightly held electrons and the strong, short carbon-fluorine bond mean that the fluorocarbon molecules are repellent to attack from other atoms or molecules. Hence, their solvent resistance is extremely high.


dbose

  • Member
  • Posts: 597
Reply 2 on: Aug 19, 2018
Wow, this really help

amit

  • Member
  • Posts: 364
Reply 3 on: Yesterday
YES! Correct, THANKS for helping me on my review

« previous next »
 

Did you know?

After 5 years of being diagnosed with rheumatoid arthritis, one every three patients will no longer be able to work.

Did you know?

To prove that stomach ulcers were caused by bacteria and not by stress, a researcher consumed an entire laboratory beaker full of bacterial culture. After this, he did indeed develop stomach ulcers, and won the Nobel Prize for his discovery.

Did you know?

In most climates, 8 to 10 glasses of water per day is recommended for adults. The best indicator for adequate fluid intake is frequent, clear urination.

Did you know?

There are major differences in the metabolism of morphine and the illegal drug heroin. Morphine mostly produces its CNS effects through m-receptors, and at k- and d-receptors. Heroin has a slight affinity for opiate receptors. Most of its actions are due to metabolism to active metabolites (6-acetylmorphine, morphine, and morphine-6-glucuronide).

Did you know?

If all the neurons in the human body were lined up, they would stretch more than 600 miles.

“Mission Accomplished” proclaimed the banner on the USS Abraham Lincoln, where on May 1, 2003, Presi “Mission Accomplished” proclaimed the banner on the USS Abraham Lincoln, where on May 1, 2003, Presi
Shifts between Warm and Cold Periods during the Last 3 Million Years Shifts between Warm and Cold Periods during the Last 3 Million Years
Under ideal conditions, a single cell of the bacterium E. coli would divide every 20 minutes to ... Under ideal conditions, a single cell of the bacterium E. coli would divide every 20 minutes to ...
A $50 000 bond bearing interest at 6.5% bond payable semi-annually matures in 10 years. If it ... A $50 000 bond bearing interest at 6.5% bond payable semi-annually matures in 10 years. If it ...
Earth 600 Million Years Ago Earth 600 Million Years Ago
Earth 430 Million Years Ago Earth 430 Million Years Ago
Video: What is Reverse Osmosis?

For a complete list of videos, visit our video library