EMA Lecture 4

Question 1

What are the most common elements found in polymers?

Answer 1

Hydrogen, Carbon, Nitrogen, Oxygen

Question 2

How do the number of covalent bonds an atom forms relate to its position on the periodic table?

Answer 2

The number of covalent bonds is determined by the number of valence electrons in the outer shell. Elements in the same group form the same number of bonds.

Question 3

What is the difference between tetrahedral and planar molecular geometries?

Answer 3

Planar geometries have double or triple bonds while tetrahedral geometries have no double or triple bonds.

Question 4

What is a ‘bonding motif,’ and how does it affect molecular structure?

Answer 4

Bonding motif is the typical way that atoms bond, defining functional groups that determine polymer properties.

Question 5

What is a functional group, and why is it important in polymer chemistry?

Answer 5

Functional groups define polymer properties.

Question 6

What does the degree of polymerization (DP) represent in a polymer?

Answer 6

Degree of polymerization is the number of repeated units in the polymer backbone.

Question 7

How can you calculate the DP of a polymer given its molar mass?

Answer 7

Count the number of atoms, determine their molar mass, then divide the given molar mass by the calculated molar mass.

Question 8

What are the different components of a polymer chain?

Answer 8

Backbone, substituents, end groups

Question 9

How does chain-growth polymerization differ from step-growth polymerization?

Answer 9

Chain-growth begins with an initiating event followed by sequential addition of monomers.

Question 10

What is the role of an active species in controlled chain-growth (CCG) polymerization?

Answer 10

The active species initiates polymerization and forms new sites for growth at the ends.

Question 11

What is ring-opening polymerization (ROP), and how does it contribute to polymer formation?

Answer 11

ROP is a method that contributes to polymer formation by opening a ring structure for polymerization.

Question 12

What are some industrially relevant examples of polymerization methods?

Question 13

covalent bonds

Answer 13

the interatomic linkage that results from the sharing of an electron pair between two atoms

Question 14

lone pairs

Answer 14

a pair of valence electrons that are not shared with another atom in a covalent bond

Question 15

meth-

Answer 15

1 carbon

Question 16

eth-

Answer 16

2 carbons

Question 17

prop-

Answer 17

3 carbons

Question 18

but-

Answer 18

4 carbons