Exam 2

Question 1

What are the 3 main processes of radical chain growth?

Answer 1

Initiation, propagation, and termination

Question 2

What is kintetics?

Answer 2

The rate of chemical reactions.

Question 3

What are the 4 polymer reaction systems?

Answer 3

Bulk, solution, suspension, and emulsion

Question 4

What is 1 pro and 1 con of Bulk polymerization?

Answer 4

Pro: High Yield
Con: difficult to stir

Question 5

What is 1 pro and 1 con of Solution polymerization?

Answer 5

Pro: product easily removed
Con: small yield

Question 6

What is 1 pro and 1 con of suspension polymerization?

Answer 6

Pro: High purity
Con: small yield

Question 7

What is 1 pro and 1 con of Emulsion Polymerization?

Answer 7

Pro: low viscosity
Con: separation is difficult

Question 8

What is degree of polymerization?

Answer 8

Average number of repeating units in each chain

Question 9

What is viscoelasticity?

Answer 9

Viscosity: ability to flow
Elasticity: ability to stretch

Question 10

What are 3 unique properties of polymers?

Answer 10

1: chain entanglement
2: summation of intermolecular forces
3: time scale of motion

Question 11

What is chain entanglement?

Answer 11

Entangled chains inside a polymer that once molten allow to slide past on another.

Question 12

What is summation of intermolecular forces?

Answer 12

Polymers are made up of large molecules whos intermolecular forces are compounded due to size

Question 13

What is time scale of motion?

Answer 13

Polymers move slower than small molecules do.

Question 14

What are 4 molecular structures for polymers?

Answer 14

Linear, branched, cross-linked, network

Question 15

What is a linear molecular structure?

Answer 15

Repeat units joined end to end in single chains

Question 16

What is a branched molecular structure?

Answer 16

Side branched chains connected to a main chain

Question 17

What is a cross-linked molecular structure?

Answer 17

Adjacent chains joined at positions by covalent bonding

Question 18

What is a network molecular structure?

Answer 18

Three or more covalent bonds in a small molecule

Question 19

What is tacticity?

Answer 19

The spa jam arrangements of monomeric units along a polymer chain

Question 20

What are the 3 types of tacticity?

Answer 20

Isotactic, syndiotactic, and atactic

Question 21

What is isotactic?

Answer 21

All side groups facing the same way

Question 22

What is syndiotactic?

Answer 22

side groups alternate in orientation

Question 23

What is atactic?

Answer 23

Side groups oriented in a random manner

Question 24

What is stereoregularity?

Answer 24

Configuration of polymer chains

Question 25

What are the 2 types of stereoregularity?

Answer 25

Cis and Trans

Question 26

What is Cis stereoregularity?

Answer 26

Substitutents on the same side

Question 27

What is Trans stereoregularity?

Answer 27

Substitutents on the opposite side

Question 28

What are 3 factors that affect crystalinity?

Answer 28

Chain entanglement, chain length, and inter chain bonding

Question 29

What are 3 high crystalline polymers?

Answer 29

Polyethylene, polypropylene, and PET

Question 30

What are 3 high amorphous polymers?

Answer 30

Polystyrene, PMMA, and PVC

Question 31

What is a Thermoset?

Answer 31

Network structures that can’t be re-molded once set. Typically stronger than thermoplastic

Question 32

3 examples of thermosets

Answer 32

Epoxy resin, polyurethane, and Bakelite

Question 33

What is a Thermoplastic?

Answer 33

Linear polymers with minor branching and flexible chains

Question 34

3 examples of thermoplastics

Answer 34

PE, PVC, and PP

Question 35

Are elastomers thermosets or thermoplastics?

Answer 35

They can be either, as well as a rubber

Question 36

What is glass transition temperature?

Answer 36

Temperature AMORPHOUS polymers transition from rubbery solid to brittle, glassy amorphous solid.

Question 37

What is vitrification?

Answer 37

when an amorphous solid transitions to a glassy solid

Question 38

What is polydispersity?

Answer 38

Polydispersity refers to the distribution of molecular weight

Question 39

What instrument can you use to determine polydispersity?

Answer 39

Size Exclusion Chromatography (SEC) Gel Permeation Chromatography (GPC)

Question 40

What are 4 common spectroscopic techniques?

Answer 40

FTIE, RAMEN, NMR, SAX/WAX

Question 41

What does FTIR and RAMEN identify?

Answer 41

Functional Groups

Question 42

What does NMR identify?

Answer 42

Microstructure

Question 43

What does SAX/WAX Identify?

Answer 43

Arrangement of atoms or molecules in a material

Question 44

What are 3 Thermal Analyses?

Answer 44

TGA, DSC. DMA

Question 45

What are 3 Mechanical analyses?

Answer 45

DMA, MTS, and Rheology

Question 46

What is rheology?

Answer 46

Study of deformation and flow of matter

Question 47

What are 3 things TGA measures?

Answer 47

Degradation temp, thermal stability, Oxidative Stability

Question 48

What does DSC measure?

Answer 48

Exothermic and Endothermic transitions

Question 49

What does DMA measure?

Answer 49

Thermomechanical behavior

Question 50

What does MTS measure?

Answer 50

Physical Properties and tinsile strength

Question 51

What does rheology measure?

Answer 51

Flow or movement of liquids and solids