Lecture 6

Question 1

conformation of small molecules

Answer 1

bulk on side groups results in steric hindrance

Question 2

What conditions can we observe fully extended, rod-like chain conformations?

Answer 2

in solid state or when energy is 0

Question 3

If not included in crystals, chains like to ____

Answer 3

coil

Question 4

Where do we find coiled polymer chains?

Answer 4

• in amorphous melts and glasses
• in crosslinked elastomers (Gaussian)

Question 5

polymer chains are usually coiled in _______

Answer 5

solution

Question 6

the random walk model is

Answer 6

not physically realistic

Question 7

characteristic ratio

Answer 7

<h^2> = nl^2 Coo

Question 8

relationship between Coo and ridity

Answer 8

the higher Coo, the more rigid the polymer is

Question 9

What does Coo depend on?

Answer 9

Temp, solvent, monomer structure, and tacticity

Question 10

persistence length

Answer 10

a measure of how far along the backbone one needs to go before orientation changes

Question 11

persistence length formula

Answer 11

lp = Coo lcc/2

Question 12

Radius of Gyration

Answer 12

measures the distribution of mass of an object in space

Question 13

what is Rg for gaussian coil?

Answer 13

Rg^2 = 1/6 <h^2>