‘The Age of Plastics’ - boun.edu.trsevgena/sci102/Sanyal-Lecture 1...Microsoft PowerPoint - Lecture 1-SCI102.ppt [Compatibility Mode] Author Amitav Created Date 2/22/2010 5:31:10

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MACROMOLECULES

‘The Age of Plastics’

Amitav Sanyal

Department of

Chemistry

Bogazici University

SCI 102 22 Feb 2010

‘ The Graduate’ 1967

“I just want to say one word to you – just one word…. plastics.”

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BIG MOLECULES made by Linking SMALL MOLECULES....REPEATING UNITS

MACROMOLECULES

a.k.a POLYMERS

Chain of Molecules

MACROMOLECULES = Large + Molecules

POLYMERS = Many + Units

Why do we care?

Waking up one morning without Polymers i.e. Plastics?

No Toothbrush ... may be I can live without it!

If you are lucky...you may have some clothes on...cotton undergarments!

No Cell phone ....

No Computer .... i.e. No Internet or Messenger Chat!

Transport? ..... tires, automobile interiors

Communication? ..... fiber optics

Contact lenses-Garments-Umbrellas-Baby Diapers-Non Stick pans- Bank Cards & Credit Cards.....!

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DNA

Cellulose

Polymers – All Around Us

Protein

Natural Polymers

Rubber

Teflon

Nylon PVC

HDPE

Polymers: All Around Us

Synthetic Polymers

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The Responsibility of Luxury!

http://en.wikipedia.org/wiki/Marine_debris

Great Pacific Garbage Patch................ 1.5 times the size of Turkey!

How BIG is the Problem?

http://en.wikipedia.org/wiki/Great_Pacific_Garbage_Patch

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Why do we care?

Source: Denver Westword: Denver News Blog

http://www.kocaeli.bel.tr/

I care, But What can I do?

3 R’s

Reduce

Reuse!

May be not so easy?

Recycle!

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Plastics Codes

• 1 – PETE – soft drink bottles

• 2 – LDPE – plastic bags, toys

• 3 – PVC – water pipes

• 4 – HDPE – milk jugs

• 5 – PP – bottle caps

• 6 – PS – styrofoam

http://www.lotfi.net/recycle/plastic.html

Thermoplastics can be recycled....................BUT THIS IS NOT AUTOMATIC!

YOU HAVE TO DISPOSE THEM APPROPRIATELY FOR RECYCLING.........

RESPONSIBLE HUMAN BEHAVIOUR

Is There No Hope?

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www.manavata.org

Plastic bags take between 15 to 1000 years to degrade.

Designing eco-friendly, biodegradable plastics!

GOING GREEN...BIODEGRADABLE PLASTICS

GOING GREEN...BIODEGRADABLE PLASTICS

degradation

Source: Biodegradable Products Institute

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Vancouver 2010: The Green Olympics

Feature Photo: chrissatchwell / Photo above: roland

All plastics were made from corn,

plates and napkins were edible and made from potatoes

1839

Charles Goodyear improve the properties of natural rubber. Working in

Woburn, MA in 1839,

Goodyear discovers ‘vulcanization’: addition of sulfur to natural rubber

greatly enhances its elasticity and toughness

SEMI-SYNTHETIC POLYMER

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The first synthetic plastic was discovered in 1907 when a Belgian born chemist, Dr. Leo H. Baekeland, reacted phenol and formaldehyde under pressure using hexamethylenetetramine as a catalyst for the reaction. The result was a thermosetting “phenolic” plastic he named Bakelite. the market.

Bakelite was an instant commercial success. It was electrically resistant, chemically stable, heat resistant, rigid, moisture and weather resistant.

It was very widely used for its electrical insulating capability.

Baekeland sold the rights to his invention to the Eastman Kodak Company that first used it for camera bodies

Dr. Leo H. Baekeland

FIRST SYNTHETIC PLASTIC

What is this?

Classification of Polymers

Natural Polymers

Synthetic Polymers

Thermoplastic

Elastomer

Thermoset

Based on Source:

Based on Property:

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Polymers: At the Molecular Level

Skeletal Structure

Chemical Structure

Skeletal Structure

• Linear – a chain with two ends

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Skeletal Structure

• Branched – have side chains

Skeletal Structure

• Crosslinked – interconnected chains

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Chemical Structure

• Homopolymer – only one monomer

(repeating unit)

- A – A – A – A – A – A – A -

Copolymer – more than one monomer

- A – B – B – A – A – B – A -

CC

H

H

H

H

SAME AS

SAME ASC

C

C

C

C

C

C

C H

H

H

H

H

H

H

H

CHEMICAL SHORTHAND

MONOMERS

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Plastics Around You

PhCH3

n

Ph Ph Ph Ph Ph PhPhStyrene

Polystyrene

Plastics Around YouMonomer Polymer

Ethylene

H3CCH3

nRepeat unit

Polyethylene

CH3

CH3

n

CH3 CH3 CH3 CH3 CH3 CH3CH3Propylene

Polypropylene

PhCH3

n

Ph Ph Ph Ph Ph PhPhStyrene

Polystyrene

ClCH3

n

Cl Cl Cl Cl Cl ClClVinyl Chloride

Poly(vinyl chloride)

F2C CF2

Tetrafluoroethylene

F3C

F2

CCF2

F2

CCF2

F2

CCF2

F2

CCF2

F2

CCF2

F2

CCF2

CF3

nPoly(tetrafluoroethylene): Teflon

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Classification based on Property

Thermoset: cross-linked polymer that cannot be melted

tires

Thermoplastic: Meltable plastic

plastic bags

Elastomers: Polymers that stretch and then return to their original form:

often thermoset polymers

rubber bands

soles of sport shoespolyurethanes: seating foams

Plasticizers or dispersants are additives that increase the plasticity or fluidity of the

material to which they are added

most commonly phthalates, that give hard plastics like PVC the desired flexibility and

durability.

New Car Smell is not the same as the New baby smell!

Connecticut was the first US state to ban bisphenol A from infant formula and baby

food containers, as well from any reusable food or beverage container.

http://en.wikipedia.org/wiki/Bisphenol_A

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Discovered in 1965 at DuPont

! 5 times stronger than Steel on equal weight basis

Application Areas:

Bullet Proof Vests

Racing Cars

Race Boats and Canoes

Bicycle Tires

POLYMERS ARE LIFESAVERS

KEVLAR

N

N

H

H

H

H

Cl

Cl

O

O

+

N

N

H

H

O

O

N

N

H

H

- n HCl

KEVLAR

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AMIDE BOND

HYDROGEN ATOMS

Bound to

Electronegetive Atom

O, N and F

KEVLAR

Nature’s Choice! ... Robust Bonds.......Bonds in Proteins

INTERCHAIN HYDROGEN BONDING

Hydrogen Boding between Polymer Chains saves lives!

Bioinspired Design... Hydrogen Bonding between Biopolymers is the basis of life!

KEVLAR

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Hydrogen Bonding…. What binds us together!

Hydrogen Bonding…. What binds us together!

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How can we learn from Nature to design Smart Materials............

..........................self-healing?

..........................self-cleaning?

...........................

...........................

Polymer Design and Applications (Lecture 2)

Nanomaterials: Polymers and others.... (Lecture 3)

THANK YOU!

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