Chemistry Reference
In-Depth Information
8. What are spherulites? How are they observed?
9. Explain the difference between a crystallite formed from the melt and a polymer crystal formed
from a dilute solution
Section 2.3.1
1. What are the three different interfacial free energies that are characteristics of crystals?
2. What equation described the dependence of the melting temperature of a polymer crystal upon its
chain length? Explain and write the equation.
3. What is the first order transition temperature?
Section 2.3.2
1. How can one obtain information on the kinetics of crystallization
2. What is the Avrami equation and what are its drawbacks?
Section 2.4
1. What are mesophases ?
2. What is anisotropic behavior?
3. What are lyotropic and thermotropic liquid crystals?
4. Explain nematic, smectic, and cholesteric liquid crystal arrangements.
5. Which of the two polymers would you expect to exhibit liquid crystalline behavior? Explain.
O
n
O
n
O
A
B
6. What is the difference between the main chain and side chain liquid crystals?
Section 2.5
1. What happens to the arrangement of the polymeric chains in films and fibers upon application of an
external stress?
2. What is orientation and how does that benefit the properties of polymeric materials?
