Lecture 1

Question 1

polymer definition

Answer 1

large molecule composed of repeating structural units

Question 2

how are subunits in polymers usually connected?

Answer 2

covalent chemical bonds

Question 3

covalent bonding

Answer 3

two nuclei share electrons between them

Question 4

ionic bonding

Answer 4

two nuclei have electrostatic attraction

Question 5

electronegativity

Answer 5

the ability of an atom to attract electrons when the atom is in a compound

Question 6

energy of covalent bonds

Answer 6

-lower total energy
-directional

Question 7

energy of ionic bonds

Answer 7

in solid state, interact through coulomb potential

Question 8

energy of van der waals

Answer 8

individual bonds can readily break and form at room temp

Question 9

energy of hydrogen bonds

Answer 9

requires H bond to NOF, enhances polymer toughness

Question 10

pi bond

Answer 10

double/triple bonds

Question 11

sigma

Answer 11

single bonds

Question 12

Cis double bond

Answer 12

two largest R groups are on same side of double bond

Question 13

Trans double bond

Answer 13

two largest R groups are on opposite side of double bond

Question 14

bonding in a polymer with other molecules on the same chain

Answer 14

intramolecular interaction

Question 15

bonding in polymers with other polymer chains

Answer 15

intermolecular interaction

Question 16

synthetic polymers

Answer 16

-will always have dispersity in MW
-not broad
-radical, condensation reactions
-polydisperse

Question 17

natural polymers

Answer 17

-precise through sequences
-structure is identical
-polymerization through a template
-monodisperse
-narrow distribution

Question 18

Carother’s definition for synthetic polymers

Answer 18

substance whose MW exceeds 5KDa and whose structure can be represented by -R-R-R- are not capable of independent existence

Question 19

Types of synthetic polymers

Answer 19

thermoplastics, thermosets, and elastomers

Question 20

Thermoplastics

Answer 20

linear, non-crosslinked, recyclable

Question 21

ex of a high performing thermoplastic

Answer 21

PEEK

Question 22

ex of thermoplastics

Answer 22

polyolefins(PE, PP, LDPE, HDPE), PS, PVC, PMMA

Question 23

thermosets

Answer 23

permanently crosslinked, polymer networks, non recyclable

Question 24

ex of thermosets

Answer 24

epoxies, polyesters, formaldehyde based resins

Question 25

elastomers

Answer 25

flexible polymer chain, low crosslinking, can be thermoset or thermoplastic

Question 26

ex elastomers

Answer 26

natural rubber, vulcanized rubber, thermoplastic rubber

Question 27

vinyl polymers

Answer 27

polymers that are derided from monomers containing C-C bonds (PP, PVC)

Question 28

Molecular parameters that determine properties of polymers

Answer 28

1. chemical composition
2. chemistry of chain ends
3. chain architecture
4. chain configuration
5. MW and MW distributions

Question 29

homochain

Answer 29

polymers with a single type of backbone

Question 30

heterochain

Answer 30

polymers with more than one atom type in the backbone

Question 31

homopolymers

Answer 31

same monomer

Question 32

copolymers

Answer 32

different monomers

Question 33

telechelic polymers

Answer 33

polymers with reactive end groups

Question 34

chain ends determine

Answer 34

adhesion, friction, and wear

Question 35

in the case of LDPE, branching occurs through

Answer 35

backbiting

Question 36

polyfunctional monomer

Answer 36

can react with more than 2 other molecules under polymerization conditions (creates branching)

Question 37

high network density in a polymers makes it

Answer 37

brittle and rigid

Question 38

long, flexible networks that are loosely connected make polymers

Answer 38

rubbery and elastic