This topic contains a solution. Click here to go to the answer

Author Question: What are the key polymeric structural features common to most elastomeric materials? What will be ... (Read 70 times)

chads108

  • Hero Member
  • *****
  • Posts: 507
What are the key polymeric structural features common to most elastomeric materials?
 
  What will be an ideal response?

Question 2

Two crosslinkable polyesters are being considered for use as the resin in making a fiberglass-reinforced tank for processing various chemicals. One polyester is made from a glycol having four carbons between the alcohol groups and the other is made using the same acid but from a glycol having eight carbons between the alcohols. Compare the physical, chemical, and mechanical properties of the two resins. If the chemicals being processed are water-based, which resin is the best candidate on the basis of chemical resistance?
 
  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

leahm14

  • Sr. Member
  • ****
  • Posts: 322
Answer to Question 1

Elastomers are generally linear, aliphatic materials with structures that do not pack together easily and are therefore noncrystalline. These materials have highly random structures in their relaxed state but will become more ordered if stretched.

Answer to Question 2

The material containing the four carbons will have a higher crosslinked density and as such will have a higher shrinkage and stiffness and resistance to chemicals than the material containing the eight carbon bonds. For the same reasons as mentioned, the four carbon bonded polyester will have a better resistance to the water-based chemicals.




leahm14

  • Sr. Member
  • ****
  • Posts: 322

 

Did you know?

As many as 28% of hospitalized patients requiring mechanical ventilators to help them breathe (for more than 48 hours) will develop ventilator-associated pneumonia. Current therapy involves intravenous antibiotics, but new antibiotics that can be inhaled (and more directly treat the infection) are being developed.

Did you know?

For pediatric patients, intravenous fluids are the most commonly cited products involved in medication errors that are reported to the USP.

Did you know?

About one in five American adults and teenagers have had a genital herpes infection—and most of them don't know it. People with genital herpes have at least twice the risk of becoming infected with HIV if exposed to it than those people who do not have genital herpes.

Did you know?

A recent study has found that following a diet rich in berries may slow down the aging process of the brain. This diet apparently helps to keep dopamine levels much higher than are seen in normal individuals who do not eat berries as a regular part of their diet as they enter their later years.

Did you know?

Cocaine was isolated in 1860 and first used as a local anesthetic in 1884. Its first clinical use was by Sigmund Freud to wean a patient from morphine addiction. The fictional character Sherlock Holmes was supposed to be addicted to cocaine by injection.

For a complete list of videos, visit our video library