Exam 1 Polymers

Question 1

What was the first semisynthetic polymer?

Answer 1

nitrocellulose (aka guncotton) developed by Christian Schonbein in his kitchen (initiated by heat)

Question 2

What was the first synthetic polymer based on phenol and formaldehyde?

Answer 2

Bakelite developed by Leo Baekeland → is strong and durable and is substitute for parts in auto and electric industries → even used to make billiard balls

Question 3

What was the importance of polyethylene?

Answer 3

discovered in 1933 to insulate radar equipment for airplanes

Question 4

What was the importance of polyamide?

Answer 4

discovered in 1935 as nylon to replace silk which was first used as material for women stockings but then used as material for parachutes during world war II

Question 5

What was the importance of Teflon?

Answer 5

discovered in 1938 and used in atomic bombs to isolate hot isotopes of uranium

Question 6

What was the importance of synthetic rubbers?

Answer 6

discovered in 1942 and took 1 hour to synthesize (whereas took 7 years for natural rubbers to grow from trees) and used for tires and military supplies

Question 7

What are the uses of polymers in pharmaceutical and biomedical products?

Answer 7

1. controlled drug delivery
2. scaffolds for tissue engineering
3. oral drug delivery → coating, binders, taste maskers, protective agents
4. transdermal patches

Question 8

What is a polymer?

Answer 8

a large molecule that is made up of many small repeating units (parts) → aka linking up monomers (the repeating unit) together → is a subset of macromolecules

Question 9

What are some other terms to describe polymers?

Answer 9

1. macromolecules → any large molecule (not necessarily those made of repeating units) → polymers are a subset of macromolecules
2. plastics → plastic materials can be molded, cast, extruded, drawn, thermoformed, or laminated into a product

Question 10

What are examples of natural polymers?

Answer 10

1. nucleic acids (DNA, RNA)
2. proteins (gelatin)
3. polysaccharides (cellulose, chitosan, alginic acid)

Question 11

What are examples of synthetic polymers?

Answer 11

1. polyethylene
2. poly(vinyl chloride)
3. poly(tetrafluoroethylene) → aka Teflon
4. polyurethane
5. polyacrylate
6. poly(p-phenylene terephthalamide) → aka Kevlar (used for bulletproof vests)
7. nylon
8. silicon rubber
9. rayon

Question 12

How are polymers named?

Answer 12

poly(repeating unit) → the repeating unit is a singular unit/form and is not plural → example is polyhuman or poly(cute child)

Question 13

What is important to note when using the parentheses for naming polymers?

Answer 13

if the repeating unit is short enough, the repeating unit does not have to be in parentheses but if it is long or you want to, the repeating unit can be put into parentheses

Question 14

What is the relationship between the polymer name and the structure?

Answer 14

the repeating unit is drawn out and in brackets (has to be two carbons since they are double bonded so that one can bond can split and hold onto the other)

Question 15

What are the different structures of polymers?

Answer 15

1. homopolymer
2. random copolymer → 2 different monomers that are randomly arranged
3. alternate copolymer → 2 different monomers that are in a pattern like ababab
4. block copolymer → 2 different monomers that are in a block like aaaabbbb
5. graft copolymer → contains 2 different monomers in which one forms a side chain

Question 16

What are another two ways to describe the structure of a polymer?

Answer 16

1. linear → flows better, increased viscosity, processability, and solubility
2. cross-linked → are tougher and doesn’t flow well, more swellable, rigid, and greater thermal stability and glass transition temperature

Question 17

What are the components of the cross-linking of polyacrylamide?

Answer 17

the repeating unit is acrylamide, the cross linker is N,N-methylenebisacrylamide, and the initiator is ammonium persulfate