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 27 th 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.

2.

3.

4.

5.

6.

7.

• The discoverer pitches the claim directly to the media.

No peer review or testing of claims is possible 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. 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 isotactic H Me H Me H Me H syndiotactic Me H Me H Me H H Me H Me H Me Me H Me H H Me H Me H Me Me atactic

Polymer Tacticity: Polymethylmethacrylate (PMMA) O n OMe Me O Me O Me O Me O O Me Me O O Me Me O Me isotactic Free radical - atactic Anionic - isotactic O Me O O Me Me O O Me Me O O Me Me O O Me Me O Me syndiotactic

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 O Nylon-6 n H N O O HN 1 2 3 4 5 6 H N O N H O

Step Growth Configurations N H O H N O Nylon 6,6 mp 265 °C tg 50 °C n H N O O N H 1 2 3 4 5 6 NH O O NH HN O O H N 6 5 4 O 3 2 1 N H O N H

Chapter 2: Synthesis of Polymers

Two major classes of polymerization mechanisms 1) Step Growth 2) Chain Growth

Step Growth Polymerization: Condensation

HO 2 C CO 2 H terephthalic acid OH HO ethylene glycol O O O O 1:1 monomer ratio Poly(ethylene terephthalate) or PET or PETE = polyester n Two equivalents of water is lost or

condensed

equivalent of monomers for each

Dacron if a fiber

Step Growth Polymerization: Condensation

HO 2 C CO 2 H terephthalic acid O HO O O OH -H 2 O OH HO ethylene glycol O HO HO O O OH HO O O -H 2 O OH Biaxially stretched PETE is “Mylar” O O OH

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 H 2 N R NH 2 Cl O R' O Cl Each has functionality of 2; Can make two bonds N H R H N O R' O n Linear, soluble Nylon polymer

Mechanics of Step Growth: Cl O O Cl R' Cl H 2 N R NH 2 O H 2 N R NH 2 Cl R' O Cl H 2 N R NH 2 H 2 N R NH 2 H 2 N R NH 2 O O O O R' Cl Cl Cl O R' Cl Cl R' Cl O Cl R' Cl R' Cl O O O O H 2 N R NH 2 H 2 N R NH 2 H 2 N R NH 2 H 2 N R NH 2 H 2 N R NH 2 O H 2 N R NH 2 Cl R' Cl Cl O R' Cl Cl O R' Cl H 2 N R NH 2 O Cl O R' O Cl Cl O R' O Cl O O H 2 N R NH 2 Cl O O H 2 N R NH 2 H 2 N R NH 2 NH 2 Cl R' Cl H 2 N R R' Cl Cl O R' Cl H 2 N R NH 2 O Cl O R' O Cl O R' Cl O O O 34 COCl groups; p = 1 - [COCl]/[COCl] 0 Cl = 0 conversion

Mechanics of Step Growth: Monomer & Dimers Cl O O HN R NH 2 R' O Cl R' O Cl H 2 N R NH 2 H 2 N R NH 2 Cl O Cl O R' O Cl H 2 N R NH 2 R' O Cl H 2 N R NH O R' O Cl H 2 N R NH 2 Cl O R' O Cl H 2 N R Cl NH O 2 R' O Cl H 2 N R NH 2 Cl O R' O Cl H 2 N R NH 2 Cl O Cl R' O O H 2 N R NH 2 R' Cl O Cl H 2 N R NH 2 H 2 N R NH 2 Cl O R' O Cl H 2 N R NH 2 Cl O R' O Cl O HN R NH 2 R' O Cl Cl O R' O Cl H 2 N R NH 2 Cl O R' O Cl H 2 N R NH 2 Cl O R' O Cl H 2 N R NH O Cl R' O 30 reactive groups p = 1 - [COCl]/[COCl] 0 = 1-30/34 = 0.11

Mechanics of Step Growth: Monomer & Dimers & Trimers O Cl HN R' O R NH Cl O R' O Cl H 2 N R HN O H 2 N R NH 2 O R' O H 2 N R NH O R' O R' Cl H 2 N R NH 2 O HN R NH 2 H 2 N R NH O Cl R' O Cl O HN R NH 2 R' O Cl H 2 N R NH 2 H 2 N R NH 2 O HN R NH R' O Cl O R' Cl O Cl O R' Cl O R' HN R NH 2 O Cl O R' HN R NH 2 O O HN R NH 2 H 2 N R NH Cl O R' O Cl H 2 N R H N O R' O Cl O HN R NH 2 R' O Cl Cl O R' O Cl O Cl R' O 19 reactive groups p = 1 - [COCl]/[COCl] 0 = 1-19/34 = 0.44

Mechanics of Step Growth: Monomer, Dimers, Trimers, & Tetramers O O H N HN R' R Cl R' NH 2 O R O H 2 N NH O R NH 2 R HN O R' O NH R' O Cl Cl H 2 N R NH O R' Cl H 2 N R HN R' O O N H R NH 2 O HN R HN O H 2 N R NH 2 O H 2 N R NH 2 R' R' HN R NH 2 O R' O O Cl O O Cl HN R NH R' Cl O R' Cl O Cl O R' O HN R NH O O R' Cl O HN R NH R' O O Cl H 2 N R H N O O R' Cl O HN R NH 2 R' O HN R NH O R' Cl O 13 reactive groups p = 1 - [COCl]/[COCl] 0 = 1-13/34 = 0.62

Mechanics of Step Growth: Monomer, Dimers, Trimers, Tetramers & Higher O H N HN R' R NH 2 O O R Cl NH H 2 N R O HN R NH R' O O R' O NH R' O HN R NH 2 H 2 N R H 2 N R HN HN O O R' O N H R NH O Cl O R' R' O O R' HN R NH 2 NH R NH O R' O O O NH R NH HN R NH O HN R NH R' O Cl O R' O O R' Cl O HN R NH R' O Cl O HN R NH R' O O Cl R' O O HN R NH 2 R' O HN R H N O R' 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 R' H 2 N R NH O R' HN R NH O HN R HN O O NH R' R' O N H R O O O NH R NH O Cl R' O O R' HN R NH O R' O N H R H N R' O O N H R H N H 2 N R HN O

Mechanics of Step Growth: Monomer, Dimers, Trimers, Tetramers & Higher H 2 N R NH O R' O HN R O NH R' O HN R HN O O HN R N H O R' HN R NH R' O O HN R NH O R' O HN R NH O O R' NH R HN O O R' N H HN R O R' O R' O Cl R NH NH O R' O O O R' N H R N H R NH O R' O R' O NH R NH HN R HN O O R' O NH R NH O R' O HN O R' HN R NH O HN R NH R' O O 1 reactive groups p = 1 - [COCl]/[COCl] 0 = 1-1/34 = 0.97

Mechanics of Step Growth: Monomer, Dimers, Trimers, Tetramers & Higher O O H 2 N R NH O R' HN R NH R' O HN R HN O O O NH R' O R' O N H R NH R NH O O O R' O HN R NH R' HN R NH R' O Cl HN R O O R' HN O N H O R' HN R R' HN R O NH O R' O NH R O R' NH If R = R’ = Phenylene = Kevlar O O Mw = 4014 g/mol O HN R NH HN R' NH R HN NH O O R NH O O O HN R' R R' O R' HN R R' NH N H R O N H O O 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.

1000

X n

 1 1 

p

100  10

X n =

Degree of polymerization

p

= mole fraction monomer conversion 1 0 0.1

0.2

0.3

0.4

0.5

0.6

0.7

Mole Fraction Conversion (p)

0.8

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 O H 2 N R NH O R' HN R NH R' O HN R HN O O O NH R' O R' O N H R NH R NH O O O R' O HN R NH R' HN R NH R' O Cl HN R O O R' HN O N H O R' HN R R' HN R O NH O R' O NH R O R' NH If R = R’ = Phenylene = Kevlar O O Mw = 4014 g/mol O HN R NH HN R' NH R HN NH O O R NH O O O HN R' R R' O R' HN R R' NH N H R O N H O O X or DP = 1/(1-p) = 1/1-0.97 = 1/0.03 = 33

Impact of percent reaction, p, on DP Degree of Polymerization, D.P. = No / N = 1 / (1 - p) Assuming perfect stoichiometry if p = 0.5

0.7

0.9

0.95

0.99

0.999

DP = 2 3.3

10 20 100 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 K eq = 1-10 • Amides from Acids and amines K eq = 10-1000 • Amides or esters from acid chlorides, K eq >10 4

Interfacial Polymerization: Nylon Rope trick

Driving Reactions forward with physics

O Cl Cl O hexanedioyl dichloride or adipoyl chloride H 2 N NH 2 hexane-1,6-diamine O O HN N H n Adipoyl chloride in hexane Nylon 6,6 Diamine, NaOH, in H 2 O

Biaxially stretched PETE is “Mylar” O O O O T g T m = 70 ° C = 265 ° C O O O T g T m < 0 ° C = 50 ° C O n n

Step Growth Polymerization: Condensation

O HO O HO O O O O OH -H 2 O OH HO O O O O O O O OH Each reaction occurs at approximately the same rate.

Any monomer or growing oligomer can participate

Step Growth Polymerization: Condensation

O HO O HO O O OH -H 2 O HO O O O O O O 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

HO 2 C CO 2 H terephthalic acid T g T m = NA = 500 ° C O HN NH O n H 2 N NH 2 diaminobenzene Kevlar

Twaron (AKZO) Nomex and Technora

H N O O H N n

Stephanie Louise Kwolek (DuPont)

Polyamides via Condensation -- Nylon 66 H O O O C (CH 2 ) 4 C O H + NH 2 CH 2 (CH 2 ) 4 CH 2 slight excess NH 2 O O O C (CH 2 ) 4 C NH 3 + CH 2 (CH 2 ) 4 O NH 3 + CH 2 Nylon Salt 60% Slurry 200 C, 15 Atm. 1 hr O O NH 3 + (CH 2 ) 6 NH C (CH 2 ) 4 C NH (CH 2 ) 6 NH C (CH 2 ) 4 C O 8-10 O O mp. 265C, Tg 50C, MW 12-15,000 Unoriented elongation 780% 270-300 C, 1hr H 2 O NH (CH 2 ) 6 NH C (CH 2 ) 4 C O Nylon 6 6 O

HO Me More Step Growth (Condensation) Polymers & their monomers OH Me Bisphenol A O Cl Cl phosgene O Me O Me Polycarbonate Lexan O n T g T m = 150 ° C = 267 ° C

Two phase: interfacial polymerization

More Step Growth (Condensation) Polymers & their monomers Na Cl O Me Me O Na O S O Cl -2n NaCl O Me Me Polysulfone O O S O Mw = 60-250K T g = 200 ° C; Films pressed at 250 Use temperature < 175 ° C ° C Stable in air to 500 ° C Self-extinguishing n

More Step Growth (Non-condensation) Polymers & their monomers ONC isocyanates CNO O O H N Polyurethane H N O O n HO OH

Polyphenylene Oxide (PPO)

Oxidative Coupling Process

R 1 OH + n/2 O 2 R 2 cat = N 10:1 or CH 3 N CH 3 3 : 1 N cat CH CH 3 3 R 1 R 1 O O R 2 R 2 + n H 2 O Cu + Amine Complex

Noryl is a blend with polystyrene Mn 30,000 to 120,000 Amorphous , Tg  Crystalline, Tm  210 270   C 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

OCN Me NCO

[RCO 2 ] 2 SnBu 2

O O Me N H N H O O n OH HO

1,4-toluenediisocyanate + 1,3-propanediol

Functionalities > 2: Crosslinking into networks

OCN NCO OCN HO OH OH O O O O NH HN O O N H O O O O

Polyurethanes (thermoset) f = 3

O NH N H O HN O 1 O O O 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 = 4 f = 3 f = 3

Phase separation = gels, glasses, or precipitates

f = 4 f = 4 f = 6

Due to chemica l bonding

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

n R 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 Polymerize fine R R R Usually polymerize R R R R Seldom polymerize R R R R R R R Almost never polymerize Almost never polymerize

Free radical Mechanism

Initiation:

NC NC N N N 2  or h  NC CN

E a = 140 – 160 kJ mol -1 K d = 8 x 10 -5 s -1 t 1/2 = 10 h at 64

°

C Propagation:

NC R

Termination:

CN R R R CN H R R R R R NC NC R k p CN R R R p  k p [ M • ][ M ]

k p = 10 2 - 10 4 L/mol s

CN R CN R R R R H R R R NC NC R t  2 k t [ M • ] 2

k t = 10 6 - 10 8 L/mol s

MW

Free Radical Polymerization Kinetics

R p

∝

[M]; R p

∝

[I] 1/2 •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 R R cat R R

Ring opening polymerization

O H + O H HO O O R = OR, NR 2 , Ph, vinyl, alkyl O n

Anionic Polymerizations:

cat = Alkyl or aryl Lithium, sodium naphalide, alkyl Grignard, some alkoxides cat R R = Ph, vinyl, CO 2 R, CN R n Vinyl polymers R cat H, Me, R n Diene polymers R n

Anionic Polymerizations:

H R O cat.

R = H, Alkyl O R n Polyacetals or carbonyls O R cat R = H, Me R O n Poly ethers

Anionic Polymerizations:

Me Me Si O Me O Me Si Me O Si Me Si O Me Me Alkoxides Me Me Me MeMe MeMe Me Si Si O O Si O Si O n Polysiloxanes

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

TiCl 4 , AlMe 3 n R R • ZN are heterogeneous; solid catalysts • Catalytic polymerizations • Early TM halide, AlR 3 on MgCl 2 • Polypropylene and HDPE • Highly productive: 10 6 g 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 = alkyl, aryl R

Not compatible with heteroatoms (O,N,S,etc)

Polymers Synthesized with Complex Coordination Catalysts

Plastics

• Polyethylene, high density (HDPE)

Bottles, drums, pipes, sheet, film, etc.

• Polypropylene, isotactic • Polystyrene, syndiotactic

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 Cl Ru PCy 3 Ph n

Examples of ROMP

No strain, no polymer O O n Me R R ° OH, NH, CO 2 H, No Reaction R n n

Acyclic Diene Metathesis Polymerization R Schrock or Grubbs catalyst -CH 2 =CH 2 R n

Coordination-Condensation polymerization Ethylene gas is produced Not commerciallized

Redox Polymerizations H N anodic oxidative polymerization H N n H N [O] H N H N H N H N H H H N -2H + H N H N

Polypyrrole

H N n H N H H H N

Redox Polymerizations NH 2 -2H + NH 2 NH 2 H N NH 2

Polyaniline

H N H H NH 2 H N n NH 2

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

• 1 H & 13 C 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 Emulsion Mini-emulsion Micro-emulsion Monomer in oil Initiator in oil Monomer in oil Initiator in water 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

HO O O Solid State Polymerizations

Heating Oligomeric Condensation Polymers

O O O n O O

T g < X < T m

O OH HO OH 250 °C O

T g = 67

°

C and T m = 265

°

C

O O

Nylons, Polyesters

O O O O O O n

Nylon 66 T g

°

C = 70

°

C and T m = 264

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 SOURCE: Nexant/ChemSystems 2005, PTAI 1/05

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” LDPE (0.915-0.930) “Low Density” LLDPE (0.860-0.926) “Linear Low Density” O C-OH O O O O O 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

Fig 2. Tubular-type reactors Fig1. Bell-jar 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

• 1 H & 13 C Nuclear Magnetic Resonance spectroscopy (NMR) • Infrared spectroscopy (Fourier Transform IR) • Elemental or combustion analyses • Molecular weight

13 C NMR is a very powerful way to determine the microstructure of a polymer.

2 1 1 2 13 C 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)

13 C NMR spectrum of CH 3 region of atactic polypropylene

Infrared Spectroscopy: Bond vibrations

C=C-H C-H polystyrene C=C stretch 2-16 Micron wavelength range

Infrared Spectroscopy: Bond vibrations

C=O C-H bend C-O C-H stretch Poly(methyl methacrylate)

Types of Addition Polymerizations

Anionic

C 3 H 7 Li

Radical

Ph PhCO 2 •

Cationic

Ph PhCO 2 Ph n Ph Cl 3 Al OH 2 Ph C 4 H 9 Ph Li + n Ph H HOAlCl 3 Ph n Ph C 4 H 9 Ph n Ph Li + PhCO 2 Ph n Ph H Ph n Ph HOAlCl 3

Chemical Modification of Polymers

1) Hydrolysis 2) Oxidation

Polyvinylacetate polyvinyl alcohol O O n NaOH H 2 O CH 3 Poly ethylene oxide OH n hv, O 2 H O n or ascorbic acid n H 3 C O O Me O H Na +

3) Photochemistry (can be oxidation or not)

Polysilane R R R R Si R R Si Si R R Si Si R R h  : UV O 2 R R Si O R Si R O O Si R Si O R R R

4) Chemical crosslinking

H S 8  S S S polybutadiene

5) Chemical modification See next slide

Chemical Modification of Polyvinyl Alcohol to make Polyvinyl butyral for safety glass

polyvinyl alcohol poly vinyl butyral CH 3 CH 2 CH 2 CHO OH OH OH OH OH O O OH O O

No PVB With PVB

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)