Polymer Chemistry Exam 1 Flashcards
(139 cards)
1
Q
What does the number average degree of polymerization represent, in words not math symbols?
A
The average number of monomers per polymer chain.
2
Q
What does the number average molecular weight represent, in words, not math symbols?
A
The average molecular weight of a polymer chain
3
Q
Without explaining what the two individual terms mean, what does this math as a whole represent:
(Nx) * (x)
A
The total number of monomers present in the sample
4
Q
Without explaining what the two individual terms mean, what does this math as a whole represent:
(Mx) * (Nx)
A
The total mass of the sample
5
Q
Without explaining what the three individual terms mean, what does this math as a whole represent:
(Mo)(x)(Nx)
A
The total mass of the sample
6
Q
Without explaining what the three individual terms mean, what does this math as a whole represent:
(Mo)(x)
A
The molecular weight of a single polymer chain with a degree of polymerization x
7
Q
Lower case “x” in polymer chemistry notation usually represents what?
A
Degree of polymerization
8
Q
Lower case “n” in polymer chemistry notation usually represents what?
A
Number of repeat units
9
Q
(Mo) in polymer chemistry notation usually represents what?
A
The molecular weight of an (incorporated) monomer.
10
Q
(Mx) in polymer chemistry notation usually represents what?
A
The molecular weight of a single polymer chain whose degree of polymerization is x
11
Q
(Nx) in polymer chemistry notation usually represents what?
A
The total number of chains whose degree of polymerization is x.
12
Q
(Wx) in polymer chemistry notation usually represents what?
A
The total mass of ALL chains whose degree of polymerization is x
13
Q
What is the mathematical relationship between number of repeat units and degree of polymerization?
A
Degree of polymerization = (Number of repeat units) * (Number of monomers PER repeat unit)
14
Q
Conceptually, what is the difference between a number average and a weight average?
A
The weight average gives extra importance to longer chains by summing up quantities proportional to the SQUARE of the chain lengths instead of just summing up things that are proportional to chain length.
15
Q
Describe a stepwise type of polymerization
A
A polymerization mechanism where chains of any length can combine with each other, as long as the function groups of the respective chains can react.
16
Q
Describe an addition polymerization propagation
A
When a polymer chain with an active site grows by adding a single monomer to the active site. The active site is then transferred to that newly added monomer.
17
Q
What is another name for a stepwise polymerization mechanism that creates a byproduct?
A
An elimination mechanism. Or a condensation polymerization if the byproduct is water, which it often is.
18
Q
What are the three steps of an addition polymerization?
A
Initiation, propagation, deactivation
19
Q
For an addition polymerization, what are two examples of deactivations which are terminations?
A
Termination by combination, Termination by disproportionation
20
Q
What is the difference between a deactivation that is a termination and one that isn’t?
A
In a termination, the active site no longer exists anywhere. In the other types of deactivation the active site is just transferred off of the current chain to somewhere else.
21
Q
In an addition polymerization, if the active site gets transferred in a deactivation step, what can it be transferred TO?
A
A monomer
Another polymer chain
A different region of the same chain
The solvent
A chain transfer agent
22
Q
When many long branches sprout from a single monomer, what type of polymer geometry results?
A
A star polymer
23
Q
A polymer whose branches very often quickly lead to other branches is what type of polymer geometry?
A
A dendrimer
24
Q
A polymer with tertiary branch points spaced close together is what type of polymer geometry?
A
A comb polymer
25
A polymer with quaternary branch points spaced close together is what type of polymer geometry?
A brush polymer
26
A polymer where all or nearly all chains are somehow connected is what type of polymer geometry?
A network
27
When two polymers are chemically linked, what is that process called? Give multiple synonyms.
Crosslinking (preferred term)
Curing (also fine)
Vulcanization (Primarily used when referring to elastomers, e.g. rubber, and especially used when linking is done by adding sulfur)
28
What is the difference in the structure of HDPE and LDPE?
HDPE is very linear and packs well, giving it a higher density. LDPE is very branched and does not pack well.
29
What is LLDPE structurally?
A polyethylene polymer with regular predictable short branches that has been polymerized by a catalyst. Sometimes ethylene is not the actual monomer used.
30
What is the difference structurally between a thermoplastic and a thermoset?
The thermoset is crosslinked and the thermoplastic is not.
31
What are some differences in the properties of a thermoplastic vs a thermoset?
- The thermoplastic can be melted and reformed into a new shape and the thermoset cannot.
- The thermoplastic is easier to recycle than the thermoset.
-Thermosets have more stable dimensions (temperature resistant, fine detail is possible).
-Thermoplastics are easier to polish smooth.
-Thermoplastics resist shattering/cracking more.
32
What is the difference between a HHTT and a HT polymer?
In a HT polymer monomers add so that the least functionalized end of one monomer adds to the most functionalized end of the other monomer. And in HHTT they do the opposite.
33
What is a meso diad?
Two monomers added next to each other such that their functional groups fall on the same side of the polymer chain from a chirality standpoint.
34
What is a racemic diad
Two monomers added next to each other such that their functional groups fall on opposite sides of the polymer chain from a chirality standpoint
35
A polymer chain made up of a single type of monomer is called what?
A homopolymer
36
A polymer chain made up of more than one type of monomer is called what?
A copolymer
37
A copolymer where it is very UNLIKELY that a monomer has reacted with a monomer of the same type is called what?
An alternating copolymer
38
A copolymer in which the monomers types are separated spatially on a linear chain is called what?
Block copolymer
39
A copolymer where the branches have different monomers than the main chain is called what?
A graft polymer.
40
How does one calculate a polydispersity?
By dividing a weight average by a number average
41
Conceptually what does polydispersity represent?
How similar in length the chains are. The closer the polydispersity is to 1, the more similar the chains are.
42
A polymer made up of all meso diads is called what?
An isotactic polymer
43
A polymer made up of all racemic diads is called what?
A syndiotactic polymer
44
A polymer where there is no long range stereochemistry pattern is called what?
An atactic polymer
45
When different arms of a star polymer have different chemistry than each other, what type of polymer is that?
Variegated
46
A copolymer in which both types of monomers can react with each other with some predictable pattern that is not usually a block or alternating but a predictable combination of the two is called what?
A statistical copolymer
47
HHTT and HT are what type of isomers?
Sequence
48
isotactic, syndiotactic, and atactic are what sort of isomers?
Stereoisomers
49
If you have the same pairs of monomers, arranging them as a block copolymer vs an alternating copolymer is making what type of isomers?
Structural
50
Chain trainsfer to self is better known as what?
| B
Backbiting
51
52
What is Fenton's reagent
An initiator system for radical polymerizations which involves adding iron (II) ions to the radical source to better control its production
53
A chemical added to an addition polymerization for the express purpose of inducing chain transfer to it is called what?
A chain transfer agent
54
In a radical polymerization of a monomer that "should" make a linear polymer, what length branches are most common and why
1 carbon: Because the active site attacks the nearest neighbor on the chain
4 carbons: Because it forms a six membered ring intermediate when backbiting
Other numbers are unfavored either because of angle-strain or because of entropy considerations
55
What is it called when an addition polymerization is designed such that deactivation never or hardly ever occurs
A living polymerization
56
A polymerization where the reaction vessel is constantly being replenished with monomers and the finished product is constantly being removed is called what?
A continuous polymerization
57
What do you call a polymerization which occurs without solvent
NEAT!
(or bulk, or melt)
58
Describe a suspension polymerization
When all the ingredients for a polymerization are placed into a non-solvent then physically agitated into small droplets which each polymerize.
Droplet size determined by the agitation, and are usually larger than emulsion droplets.
59
What is a surfactant?
A chemical with a polar and non-polar end that likes to sit at the interface between two immiscible liquids
60
What do you call tiny droplets of liquid stabilized by surfactant that are floating in another liquid?
Micelles
61
Describe an emulsion polymerization
- Let the continuous phase be "X"
- The monomer is not soluble in X.
- The initiator is soluble in X
- There is a surfactant.
- Surfactant micelles initially form with agitation, but are then chemically stable.
- Polymerization occurs inside the micelles, which swell up with completed polymer over time. They still unusually stay smaller than suspension droplets.
- End size is determined by the surfactant to monomer ratio.
62
A polymerization which occurs where two immiscible solvents meet is called what?
An interfacial polymerization
63
What sort of chemical(s) make up a Ziegler-Natta catalyst?
A transition metal compound from group IV to VIII and
a co-catalyst that is organometallic with a metal from group I-III
64
This type of catalyst would produce polymers with what type of stereochemistry?
Alternating blocks of isotactic and atactic
65
This type of catalyst would produce polymers with what type of stereochemistry?
Syndiotactic
66
This type of catalyst would produce polymers with what type of stereochemistry?
Isotactic.
67
Although I don't want the EXACT name of the polymer that would result, based on the bond that is formed, what sort of polymer do these monomers make when polymerized in a stepwise fashion?
Polyurethane
68
Draw an example of a polyurethane polymer
Anything that has these sort of linkages
69
What sort of monomers could be used to create this polymer?
These monomers would form the polyurethane polymer shown.
70
Based on the groups that react, a nylon polymer like this is also called what?
A polyamide polymer
71
When these monomers react, what is the polymer and what is the byproduct?
Nylon 3,7 with a biproduct of water
(know how to make other nylons as well)
72
When these monomers react, what is the polymer and what is the byproduct?
Nylon 3,7 with a byproduct of methanol.
(know how to make other nylons as well)
73
When these monomers react, what is the polymer and what is the byproduct?
Nylon 3,7 with a byproduct of HCl
(know how to make other nylons as well)
74
What sort of polymer is this, and what monomer(s) would form it?
It is a polycarbonate. And you would need these:
75
What polymer would be made by these monomers?
You'd make a polycarbonate. This particular one is poly (bisphenol A carbonate) or BPA
76
What is a common polymer that goes by the abbreviation BPA
poly (bisphenol A carbonate)
77
What polymer would these monomers make, and what byproduct if any forms?
You would make this polyester with HCl as a byproduct
78
Give an example of monomer(s) that can make the following polymer
These would work. You could also replace the acyl chloride groups with esters or carboxylic acid groups.
79
What polymer would these monomers make, and what byproduct if any forms?
You would form this polyester with methanol as a byproduct.
80
What type of polymer is this and how would one synthesize it?
It is a polyester, and you could make it by polymerizing these monomers in a stepwise fashion. You could also swap the ester groups in the monomer for acyl chlorides or carboxylic acids.
81
What polymer would these monomers make and what byproduct if any forms?
You would form this polyester with water as a byproduct
82
What is the structure of plexiglass?
Plexiglass is a trademarked version of poly (methyl methacrylate), PMMA
83
What is the structure of acrylic?
Acrylic is a common name of poly (methyl methacrylate), PMMA
84
What is the polymer PMMA, and what sort of things is it used in?
Poly (methyl methacrylate). It is what plexiglass or acrylic is made from.
85
What monomer(s) are needed to make the following polymer?
To make PMMA you'll need
86
What polymer is this and what monomer(s) form it?
It is poly (methyl acrylate) or PMA
87
What polymer is formed by the polymerization of this monomer?
Its poly (methyl acrylate) or PMA
88
What is this polymer and what monomer(s) form it?
Poly caprolactam, or Nylon 6
89
If you were to polymerize this monomer, what polymer would result?
You would get poly caprolactam or Nylon 6
90
What is this polymer and what monomer(s) form it?
Poly caprolactone
91
If you polymerize this monomer, what polymer will result?
92
What is this polymer and how would you make it in a stepwise polymerization?
Poly (ethylene glycol) (PEG). Made by polymerizing this diol.
93
What is this polymer and how would you make it in an addition polymerization?
Poly (ethylene glycol) (PEG). Made by a ring opening polymerization of
94
What is the polymer PEG?
Poly (ethylene glycol)
95
What polymer results if you polymerize this monomer?
Poly (ethylene glycol) (PEG)
96
What polymer results if you polymerize this monomer?
Poly (ethylene glycol) (PEG)
97
What polymer results if you polymerize these monomers?
The polyester known as: Poly (ethylene terephthalate) (PET)
98
What is the structure of PET?
Poly (ethylene terephthalate) has this structure
99
What monomer(s) could be used to make this polymer?
There are many ways to make the ester bond needed for poly (ethylene terephthalate), (PET). Here's one way:
100
What is this polymer and what monomer(s) form it?
To make polystyrene you would need this monomer.
101
If you polymerized this monomer, what polymer would result?
Polystyrene
102
Styrofoam is made of what polymer?
Polystyrene
103
These monomers could be polymerized to make what polymer?
The polycarbonate: poly(bispheonl A carbonate) (BPA)
104
What monomers are needed to synthesize BPA?
To make poly (bisphenol A carbonate) you would need these monomers
105
When these monomers are polymerized, what polymer results?
PDMS poly(dimethyl siloxane)
106
What is the polymer PDMS?
poly(dimethyl siloxane)
107
What monomer(s) do you need in order to make poly (dimethyl siloxane)
You would need these
108
What monomer(s) do you need in order to make PTFE
To make poly (tetrafluoro ethylene) you would need this.
109
What is the more common name for the polymer poly (tetrafluoroethylene) PTFE
Teflon
110
If you polymerized the following monomer, what polymer would result?
Poly (tetrafluoro ethylene) PTFE Teflon
111
What is this polymer and what monomer did it come from?
poly (3,4-chloroprene) from this monomer
112
What is this polymer and what monomer did it come from?
Poly (1,2-chloroprene) from this monomer
113
What is this polymer and what monomer did it come from?
Poly (cis-1,4-chloroprene) from this monomer
114
What is this polymer and what monomer did it come from?
Poly (trans-1,4-chloroprene) , also called Neoprene rubber made from this monomer
115
Neoprene is made of what polymer?
Poly (trans-1,4-chloroprene)
116
Natural rubber is made of what polymer?
Poly (cis-1,4-isoprene)
117
What is this polymer and what monomer(s) make it?
This is either poly (1,2-butadiene) or poly(3,4-butadiene). Without isotopic labeling there is no difference. It came from this:
118
What is this polymer and what monomer(s) make it?
This is poly (cis-1,4-butadiene) And it came from this:
119
What is this polymer and what monomer(s) make it?
This is poly (trans-1,4-butadiene) and it came from this monomer:
120
What is this polymer and what monomer(s) make it?
This is poly (3,4 isoprene) and it came from this monomer
121
What is this polymer and what monomer(s) make it?
This is poly (1,2 isoprene) and it came from this monomer
122
What is this polymer and what monomer(s) make it?
This is natural rubber. Also called poly (cis-1,4-isoprene). It is made from this monomer
123
What is this polymer and what monomer(s) make it?
This is poly (trans-1,4-isoprene). It is made from this monomer
124
What is this polymer and what monomer(s) make it?
This is poly (vinyl acetate) or PVA. It is made from this monomer
125
If you polymerize this monomer, what polymer results?
You would get poly (vinyl acetate) or PVA
126
What polymer is "Elmer's Glue" made of?
Poly (vinyl acetate) or PVA
127
What polymer is PVA
Poly (vinyl acetate)
128
Pipes can be made out of many different types of polymers. But what polymer is the most common for use in plumbing pipes?
PVC Poly (vinyl chloride)
(Also be sure you know how to name an arbitrary vinyl polymer)
129
What is PVC?
Poly (vinyl chloride)
(Also be sure you know how to name an arbitrary vinyl polymer)
130
What is this polymer, and what monomer(s) make it?
It is PVC: poly(vinyl chloride), which is made from this monomer
(Also be able to list the monomer for other vinyl polymers)
131
What is this polymer and what monomer(s) make it?
This is poly (isobutylene). PIB can be made out of
132
If you polymerized this monomer, what polymer would result?
You would get poly (isobutylene) or PIB
133
What is this polymer and what monomer(s) make it?
This is polypropylene (PP) and can be made with
134
If you polymerized this monomer, what polymer would result?
You would get polypropylene (PP)
(Also know how to polymerize and name other simple alkenes)
135
What polymer has the abbreviation PP?
Polypropylene
136
What polymer has the abbreviation PE?
Polyethylene
137
If you polymerize this monomer, what polymer results?
Polyethylene (PE)
138
What is this polymer, and what monomer(s) can be polymerized to make it?
Polyethylene (PE) made from
139
Name four types of polyethylene that we have talked about in class
High density polyethylene (HDPE)
Low density polyethylene (LDPE)
Linear low density polyethylene (LLDPE)
Highly cross-linked polyethylene (PEX) <--this one wasn't on the slides, but was part of our lab demo
