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Polymers are everywhere… You eat them, You wear them, You work with them, You use them all the time!
A polymer is a long string (or net) of small molecules connected together through chemical bonds.
A polymer is made of distinct monomerunits all connected together.
OK, but why is that important?The chain connectivity of the polymer can give the chain great strength...and at the same time they can be very flexible.
They are easily moldable, castable, soluble, spinnable, etc. ...and so many useful objects can be made from them.
It also make the polymer viscosity high in both the solution and melt state ... Now liquids behave elastically to some degree ... they are viscoelastic.
Homopolymer AAAAAAAAAAAAAAAAAAAA
Random BABABBBAABABABAABBAB
Block BBBBBBAAAAAAAABBBBBB
Alternating ABABABABABABABABABAB
Copolymers
A
A
A
Grafted BBBBBBBBBBBBBBBBBBBBA
A
AAA
AA
A
A
A
A
•Condensation Polymerization•Splits off a small molecule (usually water)•Requires at least di-functional monomers
•Addition Polymerization•No molecule split off•Involves the opening of a double bond
Polyamides
Polyesters
Polycarbonates
Linear
Cross-linked
Branched
R = Slope
Condensation
Addition
Time -->
Mo
lecu
lar
Weig
ht
R = constantimplies notermination
ANIONIC
CONDENSATION
ZIEGLER-NATTA FREE RADICAL
Type of reaction determinesmolecular weight distribution.Measured by GPC.
Thermoplastic
Thermoset
HeatCool
Heat
Solid Liquid
Crystal:very strong local order,not easily penetrated bysolvents, Tm can berelatively high
Glass:Not ordered on a molecular scale, sometimes very brittle, easily penetrated bysolvents/plasticizers
Saturates
Cyclics
Aromatics
Resins
Asphaltenes
EVA
PET
Nylon
PE
Vis
co
sit
y, P
ois
e
Pen
etr
ati
on
, u
nit
s
Temperature, F
1000
10
100
1
30 140 250 360
100
10,000
1000
10
5
1
Softening Point
Fraass Point
ConventionalAsphalt
BlownAsphalt
PolymerModifiedAsphalt
0
100
200
300
400
500
600
700
800
25 30 35 40 45 50 55 60
Time (Min)
RI R
esp
on
se Unaged
1 Mo.
2 Mo.
3 Mo.
Roofing Compound 12% SBS
