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

Author Question: Describe the processes of solvent/solute interaction that lead to swelling and, in some polymers, ... (Read 158 times)

madam-professor

  • Hero Member
  • *****
  • Posts: 584
on: Aug 19, 2018
Describe the processes of solvent/solute interaction that lead to swelling and, in some polymers, dissolving of a plastic by a solvent.
 
  What will be an ideal response?

Question 2

Explain why plasticizers increase flexibility and elongation in plastics. What is the relationship between plasticizers and the glass transition temperature?
 
  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

mbcrismon

  • Sr. Member
  • ****
  • Posts: 328
Reply #1 on: Aug 19, 2018
Answer to Question 1

Solvent molecules form secondary bonds with the polymer molecules, usually at sites on the polymer that are chemically similar to the nature of the solvent. When many of these secondary bonds form, there is sufficient energy in the molecules to allow the penetration of the solvent molecules into the polymeric structures. This causes swelling. If even more of the secondary bonds between solvent molecules and the polymer are formed, or if the secondary bonds are extremely strong, then the total polymer molecules can be separated from the other polymer molecules and total solvation occurs.

Answer to Question 2

Plasticizers are solvents that are added to swell and partially solvate the polymer. By swelling the polymer the plasticizer expands the polymer network and, therefore, allows the polymer atoms to move more freely. This greater mobility is seen as increased polymer flexibility and elongation. Raising the temperature above the glass transition temperature has the same general effect. Therefore, adding a plasticizer lowers the glass transition temperature.


madam-professor

  • Hero Member
  • *****
  • Posts: 584
Reply #2 on: Aug 19, 2018
Both answers were spot on, thank you once again


mbcrismon

  • Sr. Member
  • ****
  • Posts: 328
Reply #3 on: Aug 19, 2018
Great! Please up vote :D


« previous next »
 

Did you know?

Every flu season is different, and even healthy people can get extremely sick from the flu, as well as spread it to others. The flu season can begin as early as October and last as late as May. Every person over six months of age should get an annual flu vaccine. The vaccine cannot cause you to get influenza, but in some seasons, may not be completely able to prevent you from acquiring influenza due to changes in causative viruses. The viruses in the flu shot are killed—there is no way they can give you the flu. Minor side effects include soreness, redness, or swelling where the shot was given. It is possible to develop a slight fever, and body aches, but these are simply signs that the body is responding to the vaccine and making itself ready to fight off the influenza virus should you come in contact with it.

Did you know?

Fewer than 10% of babies are born on their exact due dates, 50% are born within 1 week of the due date, and 90% are born within 2 weeks of the date.

Did you know?

According to animal studies, the typical American diet is damaging to the liver and may result in allergies, low energy, digestive problems, and a lack of ability to detoxify harmful substances.

Did you know?

The use of salicylates dates back 2,500 years to Hippocrates's recommendation of willow bark (from which a salicylate is derived) as an aid to the pains of childbirth. However, overdosage of salicylates can harm body fluids, electrolytes, the CNS, the GI tract, the ears, the lungs, the blood, the liver, and the kidneys and cause coma or death.

Did you know?

Eat fiber! A diet high in fiber can help lower cholesterol levels by as much as 10%.

Photo of the neck of a patient with non-Hodgkin’s lymphoma showing the swelling associated with enla Photo of the neck of a patient with non-Hodgkin’s lymphoma showing the swelling associated with enla
Bony processes found on the femur. Bony processes found on the femur.
A properly mounted 12-lead, single channel ECG. A properly mounted 12-lead, single channel ECG.
Feelings of competence, independence, and relatedness lead to a sense of overall well-being in any ... Feelings of competence, independence, and relatedness lead to a sense of overall well-being in any ...
A meter lead connected to a T-pin that was gently pushed along the signal wire of the TP sensor ... A meter lead connected to a T-pin that was gently pushed along the signal wire of the TP sensor ...
Energy Transfer Processes: Free Convection Energy Transfer Processes: Free Convection
Video: Definition of heart rate

For a complete list of videos, visit our video library