問題一覧
1
What is a polymer ?
an entangled mess of large macromolecules
2
How many units is a monomer ?
one
3
How many units is a dimer?
2
4
How many units is a trimer? ?
3
5
How many units is a oligomer?
five
6
What is a homopolymer ?
all of the units are the same
7
What is a copolymer ?
polymer made up of different monomers
8
What ska statistical polymer ?
polymer that are in an organized order
9
What is a random polymer?
a polymer that is organized in a random order
10
What are alternating copolymer ?
polymers that have altering monomers
11
What is a graft copolymer ?
a type of copolymer that has a different minor on its side chains
12
What is a blend ?
a mix of polymers
13
Explain what are skeletal structures are
a visual to show the arrangement of atoms within a polymer chain
14
What is a linear skeletal structure
a structure with 2 ends
15
What is a branched skeletal structure ?
A structure with side chains and are characterized by the number and size of branches/size chains
16
What is a network polymer ?
a network polymer is a polymer that has cross links where each chain is connected to another
17
What does a chain mean ?
a long sequence of monomers or repeating units
18
What are the three types of polymers ?
Thermoplastics, Elastomers, Thermosets
19
Ranked types of polymers based om cross linking ability (most to least)
thermosets, elastomers, thermoplastics
20
What is cross linking ?
connecting chains together, or joining repeating units or monomers
21
What are thermoplastics ?
Flow upon heating. Usually have a linear or branched structure. Can be crystalline/semi-crystalline or amorphous
22
What are elastomers ?
Think “elastic”. Stretchy. They do hold their 3D shape because there is some degree of crosslinking.
23
What are thermosets ?
Rigid. High degree of crosslinking. When heated, they may actually degrade before softening.
24
What type of polymer will undergo melting temperature (Tm)
polymers with some crystalline phases
25
What type of polymer undergoes glass transition ?
a polymer that is amorphous, they can’t melt but they can soften
26
What is a monomer ?
a molecule that undergoes reaction to form the polymer
27
What is a repeated unit
the part of the polymer that, when repeated in the chemical structure, produces the correct structure of polymer.
28
For addition polymers, repeating units and monomers….
Addition polymerization: the monomer and repeat unit have the same chemical formula (no reaction byproducts)
29
For condensation polymerization, repeating units and addition…
have different chemical formulas (there are reaction byproducts)
30
What is the difference between addition and condensation polymerization?
condensation requires to 2 monomers when addition only needs one
31
New
new
32
What is the definition of functionality ?
the minimum number of functional groups needed to create a polymer
33
What are the steps to trying to find a monomer of an esterification reaction when given a polymer
1) find functionality 2) look at the ends 3) count number of C and H in backbone
34
How do we describe the size of a polymer ?
degrees of polymerization
35
What does the degree of polymerization mean ?
the number of repeat units in a polymer
36
What is the equation for a none copolymer ?
(degree of polymerization)(molar mass of repeat unit)
37
Copolymer size is
the weighted average of each repeated unit
38
Difference between the copolymer and non copolymer
the non copolymer has only one monomer while the copolymer has more than 1 monomer that keeps appearing
39
For mechanisms of polymerization, what is the difference between step and chain polymerization
step polymerization takes a longer time to form a polymer
40
What is the difference in graphs between chain polymerization and step polymerization
step: backwards L chain: L rotated 90 degrees to the right
41
Chain—> Step —>
chain is addition step is condensation
42
New
new
43
What does a molar mass distribution graph describe
average molar mass
44
What does the first moment of distribution represent ? (Mn)
number average molar mass
45
What is the second moment of distribution? (Mw)
weight average molar mass
46
What is the notation Mo stand for ?
molar mass of repeating unit and it’s only used for a non-copolymer
47
What does the notation Xi mean ?
mole fraction of molar mass
48
What does the notation Mi mean?
molar mass of molecule
49
What does notation Ni?
number of molecules/moles
50
What does the Wi notation stand for ?
weight fraction
51
What does dispersing mean ?
measure of how spread out/ broad the molar mass distribution is
52
Degree of polymerization averages
Mn/Mo or Mw/Mo
53
Step growth polymerization
y
54
What is the lowest number minimum for a polymer to form ? And why ?
two because a functionality of two ensures that it connect with at least two other monomers, allowing a polymer to possibly form
55
What is the number functionality a branched polymer needs to have and why ?
two because this allows branched polymers to connect in a linear fashion (like step polymerization)
56
What is the functionality of of network polymer and why ?
three or more because this allows a monomer to connect to three or more monomers, which allows cross linking (3-D)
57
What is the principle of equal reactivity and why is it important ?
all chains have react with the same reactivity no matter the length as long as it has a functional group to react with. this is important because it ensures that each monomer has the same likelihood of reacting with other monomers.
58
What is linear step growth polymerization and it’s process ?
a type of polymerization where monomers with 2 or more functional groups react with each other with each other resulting in a linear polymer structure. during this process, monomers have random coupling and have an equal chance of reacting with other reactive groups
59
What is Carothers theory and why is it important?
Xn = No/N, numbers of molecules
60
What is Carothers Theory – Extent of Reaction?
It is the probability that any single functional group that was present at the start has reacted
61
Carothers Theory – Extent of Reaction equation
number of functional groups reacted / number of functional groups initially
62
What are the seven classes of polymers we should know ?
polyether, polysulphide, polyester, polycarbonate, polyamide, polyurethane, polyurea