Keywords
•
•
•
•
•
•
Derive from title
Multiple word “keywords”
e.g. polysilsesquioxane low earth orbit
Brain storm synonyms
Without focus = too many unrelated hits
If you haven’t already, get it to me
today.
Research paper topics
•
•
•
•
•
•
•
•
•
•
•
•
•
3D Stereolithography with polymers
Plastic concrete – preparation, properties & applications.
Biocompatibility of silicones
Teflon and fluoropolymers –from Heaven or Hell?
Piezoelectric polymers- how they are made, why they are piezoelectric
, and applications.
Plastic in the oceans. How long do plastics last and where do they end
up?
Plastic hermetic seals
Gas separation membranes through phase inversion
Thermally induced phase separation of polymeric foams.
The strongest plastic
Major catastrophe(s) due to a polymer
Replacing ivory with plastic (comparison of composition, structure and
properties)
Plastic explosives and rocket fuels
•Polymers from soybeans
•Furan based polymers from corn
•Bacterial and fungal attack on polymers
•Conducting polymers, new metallic materials
•Semiconducting polymers for PV
•Semiconducting polymers for OLED’s
•Polymers for stealth
•Polymers for fire protection
•Smart polymers that change properties with external
stimuli
•Reworkable, healable or removable polymers
•Photoresists
Homework
• Name files with your last name, and
HWK#
• Within file, your name, HWK title,
descriptive information (like the title of
you paper topic)
-Never make your audience work
Bibliography homework
• Due on 27th at 11:59 PM
• Based on your keyword search
• J. Am. Chem. Soc. format with title
e.g. Doe, J., Smith, J. “Proper
bibliographies for Professor Loy’s
class,” J. Obsc. Academ. B. S. 2012, 1,
234.
Recommend endnote or pages or biblio.
Pseudoscience
An established body of knowledge which masquerades as
science in an attempt to claim a legitimacy which it would
not otherwise be able to achieve on its own terms; it is often
known as fringe- or alternative science. The most important
of its defects is usually the lack of the carefully controlled
and thoughtfully interpreted experiments which provide the
foundation of the natural sciences and which contribute to
their advancement.
Johathan Hope: Theodorus' Spiral (2003)
Examples of pseudoscience:
Intelligent design, polywater, cold fusion, N-rays,
Creationism, holistic medicine, etc…
Detecting Baloney
1.
The discoverer pitches the claim directly to the media.
•
2.
The discoverer says that a powerful establishment is trying to
suppress his or her work.
The scientific effect involved is always at the very limit of
detection.
3.
•
•
4.
5.
6.
7.
No peer review or testing of claims is possible
At signal noise & no one else can replicate
Requires unique instrumentation or experience
Evidence for a discovery is anecdotal.
The discoverer says a belief is credible because it has
endured for centuries.
The discoverer has worked in isolation.
The discoverer must propose new laws of nature to explain
an observation.
Polymer Phase Diagrams
Solid: amorphous glass (below glass trans) or crystalline
& Liquid (above melting point)
Polymer Tacticity: Stereochemical configuration
• typical for addition or chain growth polymers
• not for typical condensation or step growth polymers
Me
H
Me
H
Me
H
Me
H
H
Me
H
H
Me
H
H
H
Me
H
Me
H
syndiotactic
isotactic
Me
Me
Me H
Me H
atactic
Me Me
H Me H
H
Me H
Me H
Me
Me
Polymer Tacticity: Polymethylmethacrylate (PMMA)
O
Me
O
Me
Me
O
O
Me
Free radical - atactic
Anionic - isotactic
n
Me
OMe
O
O
Me
isotactic
Me
Me
O
O
Me
O
O
Me
O
Me
Me
O
Me
O
O
Me
Me
O
O
Me
syndiotactic
O
Me
O
Me
O
Me
Why is this important?
• Tacticity affects the physical properties
– Atactic polymers will generally be amorphous,
soft, flexible materials
– Isotactic and syndiotactic polymers will be
more crystalline, thus harder and less flexible
• Polypropylene (PP) is a good example
– Atactic PP is a low melting, gooey material
– Isoatactic PP is high melting (176º), crystalline,
tough material that is industrially useful
– Syndiotactic PP has similar properties, but is
very clear. It is harder to synthesize
Step Growth Configurations
H
N
n
O
Nylon-6
O
3
HN
H
N
O
5
1
2
4
O
H
N
6
O
N
H
Step Growth Configurations
O
H
N
N
H
n
O
Nylon 6,6
mp 265 °C
tg 50 °C
O
H
N
1
N
H
O
3
5
O
6
4
2
NH
O
NH
H
N
6
4
O
HN
O
3
5
O
O
N
H
2
1
N
H
Chapter 2: Synthesis of
Polymers
Two major classes of polymerization mechanisms
1) Step Growth
2) Chain Growth
Step Growth Polymerization:
Condensation
HO2C
CO2H
terephthalic acid
HO
O
O
O
O
n
OH
ethylene glycol
1:1 monomer ratio
Poly(ethylene terephthalate)
or PET or PETE = polyester
Two equivalents of water is lost or condensed for each
equivalent of monomers
Dacron if a fiber
Step Growth Polymerization:
Condensation
HO2C
CO2H
terephthalic acid
O
O
OH
HO
-H2O
HO
O
OH
ethylene glycol
O
O
OH
HO
O
O
HO
-H2O
HO
O
OH
O
OH
Biaxially stretched PETE is “Mylar”
O
Step growth systems
•
•
•
•
•
•
•
•
•
Epoxies
Polyurethanes & ureas
Nylon & polyesters
Kevlar
Polyaryl ethers (PEEK)
Polysulphones
Polyimides
Polythiophenes & Photovoltaic polymers
Polysulfides and polyphenyl ether
Mechanics of Step Growth:
• Many monomers
• All are reactive
Mole fraction Conversion = 1 – [COCl]/[COCl]0
BB
AA
O
H2N
R
NH2
Cl
R'
Cl
O
N
H
R
Each has
functionality of 2;
Can make two
bonds
O
H
N
R'
O
n
Linear, soluble
Nylon polymer
Mechanics of Step Growth:
O
O
Cl
R'
Cl
H2N
R
NH2
Cl
O
H2N
R
NH2
Cl
R'
O
Cl
R'
Cl
Cl
O
O
H2N
H2N
R
H2N
NH2
Cl
R'
H2N
Cl
R'
Cl
O
R
Cl
Cl
R'
Cl
Cl
R'
Cl
O
O
O
H2N
R
NH2
NH2
H2N R
O
Cl
O
Cl
Cl
Cl
R'
O
H2N
R
NH2
R
NH2
O
O
O
O
O
H2N
R
NH2
H2N
R'
H2N
R
NH2
NH2
R'
Cl
O
Cl
R'
Cl
R'
Cl
O
O
O
O
O
H2N R NH
2
NH2
H2N R
Cl
Cl
R'
Cl
O
R
NH2
Cl
NH2
R
O
O
O
H2N
R
NH2
Cl
R'
Cl
H2N
R
NH2
O
H2N
R
NH2
Cl
R'
O
O
Cl
Cl
Cl
R'
O
R'
O
O
Cl
34 COCl groups; p = 1 - [COCl]/[COCl]0 = 0 conversion
Mechanics of Step Growth: Monomer & Dimers
O
O
HN
O
R
NH2
Cl
O
H2N
R
NH2
Cl
R'
O
Cl
R'
Cl
O
H2N
H2N
R
O
H2N
O
NH2
Cl
R'
Cl
R'
Cl
O
Cl
R'
O
O
O
H2N
R
NH2
H2N
R
NH2
R
O
Cl
Cl
R'
Cl
Cl
R'
O
O
H2N
R
NH2
R
NH2
NH2
H2N R
O
Cl
H2N
R
NH
O
O
Cl
O
Cl
O
H2N
R'
Cl
R'
Cl
O
NH2
O
O
O
NH2
H2N R
Cl
Cl
R'
Cl
R'
R
NH2
Cl
H2N
Cl
H2N R NH
O
NH2
R
O
O
O
H2N
R
NH2
Cl
R'
Cl
H2N
R
NH2
Cl
R'
Cl
R'
HN
R
NH2
Cl
R'
O
Cl
R'
O
O
Cl
R'
O
Cl
O
O
30 reactive groups p = 1 - [COCl]/[COCl]0 = 1-30/34 = 0.11
Mechanics of Step Growth: Monomer & Dimers &
Trimers
O
O
HN
O
R'
O
O
R
NH
H2N
R
Cl
R'
Cl
Cl
R'
H2N
R
NH
O
O
HN
R
HN
H2N
R
H2N
R'
O
O
Cl
O
Cl
R'
H2N R NH
O
H2N
O
NH2
R'
Cl
NH2
R
O
NH2
H2N
R
NH2
Cl
R'
HN
R
NH2
O
R
NH2
O
NH2
HN R
O
R'
HN
R
NH
O
Cl
O
Cl
R'
Cl
O
R'
O
O
O
Cl
HN
O
R
R'
Cl
R'
NH2
O
HN
R
NH2
H2N
H
N
R
H2N
Cl
R'
O
O
NH
O
R'
O
Cl
O
R
Cl
HN
R
NH2
Cl
R'
O
Cl
R'
O
O
Cl
R'
O
Cl
O
19 reactive groups p = 1 - [COCl]/[COCl]0 = 1-19/34 = 0.44
Mechanics of Step Growth: Monomer, Dimers,
Trimers, & Tetramers
O
O
R'
HN
R
NH
O
R'
H
N
R
NH2
O
O
H2N
R
NH
O
H2N
R
Cl
R'
Cl
O
HN
R
O
NH2
NH2
R'
R'
O
O
Cl
HN
N
H
O
Cl
R'
H2N R NH
R
H2N
NH2
HN R
R
NH2
R
Cl
R'
HN
R
HN
O
H2N
O
O
O
R'
NH2
O
R'
O
O
Cl
O
HN
R
NH
HN
R
NH
O
O
Cl
R'
Cl
Cl
R'
O
O
HN
R'
R
O
O
O
R'
O
NH
R'
Cl
Cl
O
H
N
R
H2N
O
O
R'
O
Cl
HN
R
NH2
HN
R'
R
O
NH
R'
O
O
Cl
13 reactive groups p = 1 - [COCl]/[COCl]0 = 1-13/34 = 0.62
Mechanics of Step Growth: Monomer, Dimers,
Trimers, Tetramers & Higher
O
HN
R
NH
O
R'
H
N
R'
R
NH2
H2N
R
O
O
H2N
R
NH
O
NH
O
HN
R
HN
Cl
R'
O
O
NH
O
R'
R'
N
H
O
O
R
R'
O
H2N
HN
R
R
R'
O
HN
NH2
R'
Cl
NH
R
O
O
O
HN
R
NH
HN
R
NH
O
O
NH
Cl
R'
O
O
Cl
O
Cl
R'
O
R'
O
O
HN
R'
HN
R
NH
R'
O
R'
NH2
HN R
O
NH
R
NH
O
R
O
O
NH
R'
Cl
O
O
HN
R
NH2
HN
R'
R
H
N
O
R'
O
O
Cl
7 reactive groups p = 1 - [COCl]/[COCl]0 = 1-7/34 = 0.80
Mechanics of Step Growth: Monomer, Dimers,
Trimers, Tetramers & Higher
O
H2N
R
NH
R'
NH
O
HN
R
HN
R
O
R'
HN
O
O
O
NH
R'
R
N
H
O
R'
NH
R
NH
O
O
R'
NH
HN R
O
R'
O
Cl
R'
O
O
N
H
R
H
N
R
R'
H
R N
R'
O
NH
O
Cl
R'
O
O
NH
R'
O
HN
R
R
O
HN
HN
O
R'
O
Cl
H
R N
O
O
N
H
R
NH2
NH
R'
O
R'
R'
R'
R
NH
O
O
HN
HN
NH
R
O
R'
O
O
HN
N
H
R
NH
H2N
O
O
HN
O
O
N
H
O
R
3 reactive groups p = 1 - [COCl]/[COCl]0 = 1-3/34 = 0.91
Mechanics of Step Growth: Monomer, Dimers,
Trimers, Tetramers & Higher
O
R'
NH
H2N
R
NH
O
HN
R
HN
R
O
R'
HN
O
O
O
NH
R'
R
N
H
O
O
HN
R
NH
O
R'
HN
R
NH
NH
R
NH
O
O
R'
R'
Cl
O
HN
O
O
R'
R'
O
R
O
N
H
HN
O
R'
R
HN
NH
R
O
O
NH
R'
O
O
HN R
NH
O
HN
O
R
O
R'
HN
NH
R
HN
O
NH
O
R
R'
O
N
H
HN
R
R'
O
NH
R
NH
O
O
NH
R'
O
R'
HN
O
R'
R'
O
N
H
O
R
1 reactive groups p = 1 - [COCl]/[COCl]0 = 1-1/34 = 0.97
Mechanics of Step Growth: Monomer, Dimers,
Trimers, Tetramers & Higher
O
R'
NH
H2N
R
NH
O
HN
R
HN
R
O
R'
HN
O
O
O
NH
R'
R
N
H
O
O
HN
R
NH
O
R'
HN
R
NH
NH
R
NH
O
O
R'
R'
Cl
O
HN
O
O
R'
R'
O
R
O
N
H
HN
O
R'
R
HN
NH
R
O
O
NH
R'
If R = R’ = Phenylene = Kevlar
Mw = 4014 g/mol
O
O
HN R
NH
O
O
HN
R
O
R'
HN
NH
R
HN
O
NH
O
R
R'
O
N
H
HN
R
R'
O
NH
R
NH
O
O
NH
R'
O
R'
HN
O
R'
R'
O
N
H
O
R
1 reactive groups p = 1 - [COCl]/[COCl]0 = 1-1/34 = 0.97
Step-Growth Polymerization
• Because high polymer does not form until the end of the
reaction, high molecular weight polymer is not obtained
unless high conversion of monomer is achieved.
Degree of Polymerization
1000
Xn = Degree of polymerization
p = mole fraction monomer
conversion
Xn 
1
1 p
100

10
1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Mole Fraction Conversion (p)
0.9
1
Degree of Polymerization for step growth polymers
X = [COCl]0/[COCl] = 1/1-p
Mechanics of Step Growth: Monomer, Dimers,
Trimers, Tetramers & Higher
O
R'
NH
H2N
R
NH
O
HN
R
HN
R
O
R'
HN
O
O
O
NH
R'
R
N
H
O
O
HN
R
NH
O
R'
HN
R
NH
NH
R
NH
O
O
R'
R'
Cl
O
HN
O
O
R'
R'
O
R
O
N
H
HN
O
R'
R
HN
NH
R
O
O
NH
R'
If R = R’ = Phenylene = Kevlar
Mw = 4014 g/mol
O
O
HN R
NH
O
HN
R
O
R'
HN
NH
R
HN
O
NH
O
R
R'
O
N
H
HN
R
R'
O
NH
R
NH
O
O
R'
HN
O
R'
R'
O
N
H
O
R
X or DP = 1/(1-p) = 1/1-0.97 = 1/0.03 = 33
NH
R'
O
O
Impact of percent reaction, p, on DP
Degree of Polymerization, D.P. = No / N = 1 / (1 - p)
Assuming perfect
stoichiometry
if p =
0.5
DP =
2
0.7
0.9
0.95
3.3
10
20
0.99
0.999
100
1000
DPmax= (1 + r) / (1 - r) where r
molar ratio of reactants
if r = [Diacid] / [diol] = 0.99, then
DPmax= 199
Effect of Extent of
reaction on
Number
distribution
Effect of Extent of
reaction on weight
distribution
Problems in Achieving High D. P.
1. Non-equivalence of functional groups
a. Monomer impurities
1. Inert impurities (adjust stoichiometry)
2. Monofunctional units terminate chain
b. Loss of end groups by degradation
c. Loss of end groups by side reactions with media
d. Physical losses
e. Non-equivalent reactivity
f. Cyclization
.
Unfavorable Equilibrium Constant
Impact of Thermodynamics
• Esters from Acids and alcohols Keq = 1-10
• Amides from Acids and amines Keq = 10-1000
• Amides or esters from acid chlorides, Keq >104
Interfacial Polymerization: Nylon Rope trick
Driving Reactions forward
with physics
O
Cl
Cl
H2N
O
hexanedioyl dichloride
NH2
hexane-1,6-diamine
or adipoyl chloride
O
HN
O
N
H n
Adipoyl chloride
in hexane
Nylon 6,6
Diamine, NaOH, in H2O
Biaxially stretched PETE is “Mylar”
O
O
O
O
n
Tg = 70 °C
Tm = 265 °C
O
O
O
O
Tg < 0 °C
Tm = 50 °C
n
Step Growth Polymerization:
Condensation
O
O
HO
O
OH
O
HO
-H2O
O
O
O
O
O
O
O
OH
HO
O
OH
O
Each reaction occurs at approximately the same rate.
Any monomer or growing oligomer can participate
Step Growth Polymerization:
Condensation
O
O
O
OH
HO
O
HO
-H2O
O
O
O
O
O
O
HO
Impurities will kill growth and limit molecular weight
Delayed commercialization of condensation polymers
The Guy who got the ball rolling
Nylon
Polyester
Polychoroprene (Neoprene)
Dr. Wallace Hume Caruthers
Head of DuPont Organic research Labs
50 patents
More Step Growth (Condensation)
Polymers & their monomers
Polyaramides
HO2C
CO2H
terephthalic acid
H2N
Tg = NA
Tm = 500 °C
O
HN
NH
O
n
NH2
diaminobenzene
Kevlar
Twaron (AKZO)
Nomex and Technora
H
N
Stephanie Louise
Kwolek (DuPont)
H
N
O
O
n
Polyamides via Condensation -- Nylon 66
O
H O
O C-(CH2)4-C O
H
+
NH2 CH2-(CH2)4-CH2 NH2
O
O
C-(CH2)4-C
OONH3+
NH3+
CH2
CH2
(CH2)4
slight excess
Nylon Salt
60% Slurry
200 C, 15 Atm. 1 hr
O
O
NH3+(CH2)6-NH-C-(CH2)4-C-NH-(CH2)6-NH-C-(CH2)4-C O
8-10
O
O
mp. 265C, Tg 50C,
MW 12-15,000
Unoriented elongation
780%
270-300 C, 1hr
-
H2O
O
NH-(CH2)6-NH-C-(CH2)4-C
O
Nylon
6
6
More Step Growth (Condensation)
Polymers & their monomers
Me
HO
OH
Me
Bisphenol A
O
Me
O
Me
O
Cl
O
Cl
n
Polycarbonate
Lexan
phosgene
Two phase: interfacial polymerization
Tg = 150 °C
Tm = 267 °C
More Step Growth (Condensation)
Polymers & their monomers
Me
O
O
Na
Me
Na
Me
O
-2n NaCl
Cl
O
S
O
Cl
O
Me
O
S
O
Polysulfone
Mw = 60-250K
Tg = 200 °C; Films pressed at 250 °C
Use temperature < 175 °C
Stable in air to 500 °C
Self-extinguishing
n
More Step Growth (Non-condensation)
Polymers & their monomers
isocyanates
CNO
ONC
H
N
H
N
O
O
O
HO
OH
O
Polyurethane
n
Polyphenylene Oxide (PPO)
Oxidative Coupling Process
R1
R1
OH
+
n/2 O 2
R1
O
O
cat
R2
R2
R2
+ n H 2O
cat =
or
N
10:1
CH3
N
CH3
CH3
N
CH3
Cu
+
Amine Complex
3 :1
Noryl is a blend with polystyrene
Mn 30,000 to 120,000
Amorphous , Tg  210C
Crystalline, Tm  270C
Brittle point
 -170C
Thermally Stable to  370C
Step Growth Polymers
• Polyesters, polyamides, engineering
plastics such as polysulfones,
polyetherether ketones (PEEK),
polyurethanes.
• Condensation often occurs.
• Polymerization affords high MW late in
the game
Step-Growth
Non-Condensation Polymerization
Polyurethanes
Me
OCN
NCO
O
HO
Me
O
[RCO2]2SnBu2
N
H
OH
1,4-toluenediisocyanate + 1,3-propanediol
O
N
H
O
n
Functionalities > 2: Crosslinking into networks
OCN
NCO
O
OCN
O
O
O
NH
O
N
H
OH
HO
O
O
O
HN
O
OH
Polyurethanes
(thermoset)
O
f=3
NH
O
N
H
HN
O
O
O
O
O
1
1
Thermosets
•
•
•
•
•
Urethanes
Epoxies
Polyesters (2-stage)
Formaldehyde-aromatic
Melamine-formaldehyde
Generally: Start as low viscosity liquids (low Mw)
And set or cure to form glassy “vitrified” solids.
Gelation: f > 2
• If f > 2
• No cyclics form
then an infinite network is possible
(unless it phase separates!!!)
Functionality Higher than Two
f=3
Phase separation
= gels, glasses,
or precipitates
f=4
Due to
chemica
l
bonding
f=3
f=4
f=4
f=6
f=6
f=4
f=8
f=8
f=8
f = 14
Functionality = Two: Linear polymers
f=2
f=2
f=2
f=2
f=2
f=2
Physical gels may form due to poor solubility of polymer
Functionality = Three: Cyclization
f - 14
f=8
Lowers functionality & delays (or even prevents) gelation
Gel point = 1/(f -1) = 1/2 or 50% conversion
If cyclics present, gel point is higher.
Addition Polymerizations
R
n
R
1) Catalyzed polymerization
free radical
cationic
anionic
coordination
2) Active group on end of polymer
3) MW increases more rapidly
4) Cheap & easier than step growth
5) Enthalpically favorable
Free Radical Polymerizations
• Initiators (catalyst):
– Thermal: azo compounds, peroxides,
– Redox: persulfates
– Photochemical: azo, peroxides,
amine/ketone mixtures
• Monomers
R
R
Polymerize fine
R
Usually
polymerize
R
R
R
R
Seldom polymerize
R
R
R
R
R
R
R
Almost never Almost never
polymerize
polymerize
Free radical Mechanism
Initiation:
N2
NC
NC
N
Ea = 140 – 160 kJ mol-1
NC
N
CN
Kd = 8 x 10-5 s-1

t1/2 = 10 h at 64 °C
or h
Propagation:
NC
R p  k p [M•][M]
CN
kp
kp = 102 - 104 L/mol s
R
R
R
R
Termination:
CN
NC
R
R
R
R
R
CN
R
R
NC
R
R t  2k t [M•]2
kt = 106 - 108 L/mol s
H
CN
NC
R
CN
R
H
R
R
R
R
R
R
NC
Free Radical Polymerization
Kinetics
Rp ∝ [M]; Rp ∝ [I]1/2
MW
•MOST POLYMERS FORM IN SECONDS
OR LESS
• POLYMERIZATIONS TAKE HRS
TIME
Living Radical Polymerizations:
MW increases linearly with time
Narrow Mw distributions
Block copolymers
1) Atom TransfeR Polymerization (ATRP)
2) Polymerization (RAFT)
3) TEMPO
Lower concentration of propagating species
Lower termination rate
Cationic Polymerizations:
Vinyl polymerization
cat
cat
R
cat
R
R
R
R
-H+
cat
cat
R
R
R
R = OR, NR2, Ph, vinyl, alkyl
R
Ring opening polymerization
O
H+
H
O
HO
O
O
O
n
Anionic Polymerizations:
cat = Alkyl or aryl Lithium, sodium naphalide, alkyl Grignard, some alkoxides
cat
Vinyl polymers
n
R
R
R = Ph, vinyl, CO2R, CN
R
cat
R
H, Me,
n
n
R
Diene polymers
Anionic Polymerizations:
H
cat.
O
R
O
Polyacetals or carbonyls
n
R = H, Alkyl
R
cat
O
O
R = H, Me
R
R
n
Poly ethers
Anionic Polymerizations:
Me
Me O Si Me
Si
O
Me
O
Si Me
Si O Me
Me
Me
Alkoxides
Me Me Me MeMe MeMe
Me
Si
Si
Si
Si
O
O
O
O
Polysiloxanes
n
Coordination Polymerizations:
Transition Metal Mediated Polymerizations
-Ziegler Natta polymerizations (Early TM)
-ring opening metathesis polymerization (metal
Alkylidenes)
-Insertion polymerizations (mid to late TM’s)
Ziegler Natta Polymerizations
TiCl4, AlMe3
R
•
•
•
•
•
n
R
ZN are heterogeneous; solid catalysts
Catalytic polymerizations
Early TM halide, AlR3 on MgCl2
Polypropylene and HDPE
Highly productive: 106g polymer/gram
catalyst-hour
• 10,000 turn overs/second (enzyme like
speed)-diffusion limited
• Stereochemical control:
iso or syndiotactic polymers
Karl Ziegler (1898-1973)
Giulio Natta (1903-1979)
Ziegler Natta Monomers
R
-olefins
styrenes
R
R = alkyl, aryl
Not compatible with heteroatoms (O,N,S,etc)
Polymers Synthesized with Complex Coordination
Catalysts
Plastics
• Polyethylene, high
density (HDPE)
• Polypropylene,
isotactic
• Polystyrene,
syndiotactic
Bottles, drums,
pipes, sheet,
film, etc.
Automobile and
appliance parts,
rope, carpeting
Specialty
plastics
Ring Opening Metathesis
• Strained Rings with C=C bonds
• Metal alkylidene catalysts
– Ti, Mo, W alkylidenes (Schrock catalysts)
– Ruthenium alkylidenes (Grubbs catalysts)
• Living polymerizations
N
N
Cl Ru Ph
Cl
PCy3
n
Examples of ROMP
No strain, no polymer
n
O
O
n
No Reaction
Me
R
n
R
R ° OH, NH, CO2H,
Acyclic Diene Metathesis Polymerization
Schrock or
Grubbs
catalyst
R
R
n
-CH2=CH2
Coordination-Condensation polymerization
Ethylene gas is produced
Not commerciallized
Redox Polymerizations
anodic
oxidative
polymerization
H
N
H
N
n
H
N
H
N
H
N
[O]
H
N
H
N
H
H
H
N
H
H
N
-2H+
H
N
H
N
H
N
n
H
Polypyrrole
H
N
Redox Polymerizations
H
NH2
-2H+
NH2
NH2
H
N
H
N
H
NH2
H
NH2
N
NH2
n
Polyaniline
When acid doped: conducting polymer
Polymerization Techniques
• Bulk-no solvent just monomer +
catalysts
• Solution Polymerization-in solvent
• Suspension-micron-millimeter spheres
• Emulsion-ultrasmall spheres
Less Common Polymerization
Techniques
• Solid state polymerization
– Polymerization of crystalline monomers
• Diacetylene crystals
• Gas Phase polymerization
– Parylene polymerizations
• Plasma polymerization
– Put anything in a plasma
Plasma Polymerization
Characterization of Polymers
• 1H & 13C Nuclear Magnetic Resonance
spectroscopy (NMR)
• Infrared spectroscopy (Fourier
Transform IR)
• Elemental or combustion analyses
• Molecular weight
Polymerization Techniques
• Bulk-no solvent just monomer +
catalysts
• Solution Polymerization-in solvent
• Suspension-micron-millimeter spheres
• Emulsion-ultrasmall spheres
Bulk Polymerizations
Rare
Overheat & explode with scale up
No solvent-just monomer
Polymer usually vitrifies before done
Broad MW distribution
Acrylic sheets by Bulk polymerization of MMA
Storage of vinyl monomers in air = peroxide
initiated polymerizations
Tankcar of styrene
2005 in Ohio
Solution Polymerization
• Better control of reaction temperature
• Better control of polymerization
• Slower
• Not very green-residual solvent
Suspension Polymerization
• Oil droplets dispersed in water
• Initiator soluble in oil
• Greener than solution polymerization
Filter off particles of polymer
Emulsion
Polymerization
Still oil in water (or the reverse)
Initiator in water
Smaller particles (latex)
Excellent control of temp
Solution turns white
Polystyrene latex
Suspension
Monomer in oil
Initiator in oil
Emulsion
Monomer in oil
Initiator in water
Mini-emulsion Micro-emulsion
Monomer in oil
Initiator in water
Monomer in oil
Initiator in water
Less Common Polymerization
Techniques
• Solid state polymerization
– Polymerization of crystalline monomers
• Diacetylene crystals
• Gas Phase polymerization
– Parylene polymerizations
• Plasma polymerization
– Put anything in a plasma
Solid State Polymerizations
Heating Oligomeric Condensation
Polymers
Tg < X < Tm
O
O
O
HO
O
O
O
O
O
n
O
OH
HO
OH
O
O
250 °C
O
Tg = 67 °C and Tm = 265 °C
Nylons, Polyesters
Nylon 66 Tg = 70 °C and Tm = 264
°C
O
O
O
O
n
O
Solid State Polymerizations
Topological Polymerizations: Polymerization of crystals
Quinodimethane polymerizations
Di- and Triacetylene polymerizations
In single crystals
Solid State Polymerizations of Fullerenes
Topological polymerization in 3-D
Gas Phase Polymerization
1) Light olefins
2) Parylenes
LIGHT OLEFINS
Ethylene and propylene
Film
• Food Packaging
• Hygiene & Medical
• Consumer & Ind. Liners
• Stretch Films
• Agricultural Films
• HDSS
2004 Global PE Demand: 136 Billion Pounds
Types of Polyethylene
HDPE (0.940-0.965)
“High Density”
LLDPE (0.860-0.926)
“Linear Low Density”
O
O
O
C-OH
O
O
O
LDPE (0.915-0.930)
“Low Density”
O
O
O
O
O
High Pressure Copolymers
(AA, VA, MA, EA)
Gas Phase Polymerization: Light olefins
Oxygen initiator
2-3K atmospheres
250 °C
Gas Phase Polymerization: Light olefins
Fluidized bed polymerization
MORE
FLEXIBLE
Gas Phase Polymerization: Paralene
Gas phase
Polymerizes on contact
Conformal coatings
Pinhole free
Preserving artifacts (paper
Microelectronics
Medical devices
Plasma Polymerization
•500 Å - 1 micron thick films
•Continuous coatings
•Solvent free
•High cohesion to surface
•Highly cross-linked
•Generally amorphous
Plasma Polymerization
Monomers: Hydrocarbons
Double or triple bonds nice, not necessary
Fluorocarbon
Tetraalkoxysilanes (for silica)
Plasma Polymerization
Fig1. Bell-jar type reactors
Fig 2. Tubular-type reactors
P- pumps; PS-power supply; S-substrate
M-feed gas inlet; G-vacuum gauge
Plasma Polymerization
Multi-layer bottles
No loss of fizz
PET [Poly(Ethylene Terephthalate)]
Characterization of Polymers
• 1H & 13C Nuclear Magnetic Resonance
spectroscopy (NMR)
• Infrared spectroscopy (Fourier
Transform IR)
• Elemental or combustion analyses
• Molecular weight
13C
NMR is a very powerful way to determine
the microstructure of a polymer.
2
1
1
2
13C
NMR shift is sensitive to the two
stereocenters on either side on sptectrometers
> 300 MHz. This is called pentad resolution.
r
m
m
r
m
r
mmrm pentad
m = meso (same orientation)
r = racemic (opposite orientation)
13C
NMR spectrum of CH3
region of atactic polypropylene
Infrared Spectroscopy: Bond vibrations
C=C-H
polystyrene
C-H
C=C
stretch
2-16 Micron wavelength range
Infrared Spectroscopy: Bond vibrations
C-H bend
C=O
C-O
C-H
stretch
Poly(methyl methacrylate)
Types of Addition Polymerizations
Anionic
Ph
C3H7
Li
n
Li+
C4H9
Ph
Li+
C4H9
n
Ph
Ph
Ph
Radical
PhCO2•
Ph
n
Ph
PhCO2
n
Ph
Cationic
Ph
Cl3Al OH2
PhCO2
Ph
Ph
n
Ph
H
HOAlCl3
H
Ph
HOAlCl3
n
Ph
Ph
Chemical Modification of Polymers
1) Hydrolysis
polyvinyl alcohol
Polyvinylacetate
NaOH
n
O
O
2) Oxidation
n
O
H3C
OH
H2O
O
n
CH3
Poly ethylene oxide
O
hv, O2
O
H
3) Photochemistry
(can be oxidation or not)
4) Chemical crosslinking
Na+
Me
n
Polysilane
R R R R
Si
Si
Si
Si
Si
R R R R R R
H
h: UV
O2
S8

polybutadiene
5) Chemical modification
See next slide
H
or ascorbic
acid
R
R O Si R
Si
O
R
O
Si R
Si O R
R
R
S
S
S
Chemical Modification of Polyvinyl Alcohol to make
Polyvinyl butyral for safety glass
polyvinyl alcohol
poly vinyl butyral
CH3CH2CH2CHO
OH
OH OH
O
OH OH
O
OH
O
No PVB
With PVB
O
Bullet Proof Glass
Making bullet proof glass
glass, laminates and polycarbonate
sheets are interlaid in a clean room to
ensure clarity. In our large autoclave,
superheated steam seals the layers
together.
Polycarbonate is
Strong Material
Young's modulus (E)
Tensile strength (σt)
2-2.4 Gpa
55-75 Mpa
Exploding CD’s
Mythbusters:
> 23,000 rpm CD will shatter
Scratches or defects are the culprit
52X drive -MAX: 27,500 rpm
typical: 11,000 rpm
10,000 RPM = 65 m/s = 145 mph
7200 gravities of acceleration
And approx. 5 MPa stress
Yield Strength 60 MPa
Nalgene
Polycarbonate Properties
Density:
Young's modulus (E)
Tensile strength (σt)
Elongation (ε) @ break
Glass transition (Tg)
Melting (Tm)
Upper working temperature
$7.3-11/kg
1.2 g/cc
2-2.4 Gpa
55-75 Mpa
80-150%
150 °C
267 °C
115-130 °C
Bisphenol and Endocrine System
100-250 g bisphenol per Liter water in water bottles
20 g/Liter per day can disrupt mouse development
vom Saal, F.S., Richter, C.A., Ruhlen, R.R. Nagel, S.C. and Welshons, W.V. Disruption of laboratory
experiments due to leaching of bisphenol a from polycarbonate cages and bottles and uncontrolled
variability in components of animal feed. Proceedings from the International Workshop on
Development of Science-Based Guidelines for Laboratory Animal Care, National Academies Press,
Washington DC, 65-69, 2004.
Immune system
Antioxidant enzymes
Decreases plasma testosterone
Learning disabilities
vom Saal, F.S., Nagel, S.C., Timms, B.G. and Welshons, W.V. Implications for human health of the extensive
bisphenol A literature showing adverse effects at low doses: A response to attempts to mislead the public.
Toxicology, 212:244-252, 2005.
Nalgene Substitutes-food and water
•
•
•
•
Glass (blender, pitchers, glasses)
Metal (water bottles)
Polyethylene (water bottles)
Polyamide or Nylon (baby bottles)