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IPPH 363

Professor Kinam Park

PURDUEUNIVERSITY

Department of Biomedical EngineeringDepartment of Pharmaceutics

(kpark@purdue.edu)

Tooth BrushShaving bladeShampoo

Polymers in Everyday Life

LotionsSun screensMascaraCosmeticsNail enamels

Introduction to polymers

Pol mer: a substance whose molecules consist of many (poly-) parts (meros, greek) or units.

Plastic: a polymer-based material that can bemolded, cast, extruded, drawn, or laminated intoobjects, films, or filaments.

Multimer

PolymersMonomer, Dimer, Trimer Oligomer (N = 30-200)

Crosslinked gel (1940s)

Branched polymers (1960s)

Homopolymer block copolymer

Chain length: NotUniform.Average MolecularWeight.

Dendrimers (1980s)N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

NN

N N N NN

NN

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

NN

NNNN

N

N

N

N

N N

N

N

N

N

N

N

N

N

N

N N

N

N

N

N

N

N

N

N

N N

N

N

N

NN

N

N

N

N

N

N

NN

N

NN

N

N

N

N

N

N

N

N

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Polyhuman. Poly(red human)

One word.Just one word: Plastics.Theres a great future in

lastics.

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C C

H

H

C

H

C

H

HCH 3

Polyisoprene1839

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1907 . BakelitePhenol-formaldehyde resin.

The first completelyman-made substance.

Beginning of Polymers

The first thermoset plastic.

Urea-formaldehyde Resin(1929)

1907 Vinyl Polymerization

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Condensation Polymerization(Step-reaction Polymerization)

Nylon 6-10H 2 N ( CH 2 )6 NH 2 Hexamethylenediamine in water

+

Cl C

O

(CH 2 ) 8 C

O

Cl

C C

Cl

Cl C l

Cl

N ( CH 2 ) 6

+

N

Sebacoyl chloride in tetrachloroethylene

H

C

O

(CH 2 ) 8 C

OH

x

Need For New Tough Plastic.

Synthesis of nylon based onStaudingers theory on polymericnature of plastics.

C C

H

H

CH 3

C O

OCH 3

C C

H

H

CH 3

C O

OCH 2 CH 2 OH

Poly(methyl Methacrylate)

Poly(hydroxyethyl Methacrylate)

Si O

CH 3

CH 3

Silicone Rubber

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Silicone Rubber

Cohesive silicone gel implants, such asthis one made by McGhan, a division of Inamed, are designed to avoid leaks.

C C

H H

Poly(vinyl chloride)

H Cl

C C

F

F

F

F

Poly(tetrafluoro ethylene)

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Polyurethane

C C

H

H

H

Cl

OCN R NCO

HO R' OHO C

O

N

H

R N C

O

O R'

H

n

+

C C

H

H

H

COOH

Poly(acrylic acid)

CH2 CHOH n

No charge.Poor water solubility.

Poly(acrylic acid)in acid form

CH 2HC

COO

H CH 3

CH2HC

COO

H H

INTER- AND INTRAMOLECULAR HYDROGENBONDING POLYMERS

n n

(A)

Intermolecular HydrogenBonding

intermolecular hydrogen bonding. CH CH 2

CO N CH 3

CH CH 2

CO N H

CH 2HC

C

nn

n

(B)Strong Adhesive

O OCH 2

N

N

O

H

H

O NN

O

O

H2C O

CO

CH

CH2

n

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Kevlar (Poly( p -phenylene terephthalamide)

Hydrogen bonding and van der Waals forces

Gossamer Albatross crossed the English Channel in1979. It was constructed frpm a variety of plastics,including Kevlar film, Teflon, Delron, acetral resin,molded polystyrene, and carbon-reinforced polymer(E.I.; DuPont).

Stephanie Kwolek

1891. Rayon: artificial silk.

Regenerated man-made fibers of cellulose from cuprammonium cellulose,

,acetate.

Sutdy on silkworm by Louis MarieHilaire Bernigaut, Paris: Silkwormsecretes a liquid from a narrow orificethat hardens u on ex osure to air silk .

Idea: Pass a liquid that has similarcharacteristics to silk before beingsecreted through a man-made apparatusto form fibers that can spun and feel likesilk.

Tradenames: Dacron, Vycron

POLY(ETHYLENE TEREPHTHALATE)

ersMylar (films)

Applications: BiomaterialsFilm, BottlesRecording tapes

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Polyacrylamide C C

H

H

H

CONH 2

Agarose

Biodegradable Polymers

Natural Polymers

Nucleic acids

Polysaccharides

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Discovery of the DNA Structure (1953) Protein

N C C

H O

Peptide bondGelatin

RH

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Protein Folding

Introduction To Protein StructureCarl Branden & John Tooze, 1991

Introduction To ProteinStructureCarl Branden & John Tooze,

Polysaccharides

O

OH

OH

CH 2OH

O O

O

OH

OH

CH 2OHO

OC 2H5

OH

CH 2OC 2 H 5

O O

O

OC 2H 5

OH

CH 2 OC 2 H 5

O

OCH 2COOH

OH

CH 2OCH 2 COOH

O

H

O

O

OCH 2COOH

OH

CH 2OCH 2 COOH

Cellulose Ethylcellulose

Carboxymethylcellulose

O

OHOH

COOH

O O

O

OHOH

COOH

Alginic acid

O

NH 2

OH

CH 2OH

O O

O

NH 2

OH

CH 2OH

Chitosan

O

OH

OH

COO -

O OO

NH

CH 2OH

OH

C O

CH 3Hyaluronic acid

Ca++

Alginic Acid

Ch elatin gagen t

Calcium ion

O

OHOH

COOH

O O

O

OHOH

COOH

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O

NH 2

OH

CH 2OH

O O

O

NH 2

OH

CH 2OH

Starch

Bread:SoftHard

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Temperature-Sensitive Polymers & Hydrogels

Positive Thermosensitivityas T Solubility/Swelling

Ne ative Thermosensitivit

as T Solubility/Swelling

Competition between the two forces

(H-bonding & Hydrophobic interaction)Covalent bond:

~ 5 eV ( 0.8 x 10 -18 J)

Temperature dependent interactions

as T Hydrogen-bonding

as T Hydrophobic interaction

Secondary interactionforces: ~ 0.1 eV

Thermal fluctuation energy:~ 0.03 eV ( 1 kT )

Hydrophobic interactions

C

H

CH 2 C

C

H

O

N

H

( )C

H

CH 2 C

C

CH 3

O

N

H

( )

Poly(N-isopropylacrylamide Poly(N-cyclopropylmethacrylamide

Competition between hydrogenbonding &hydrophobic interactions.

H3C CH 3 H 2C CH 2

Water-soluble at low temperatureWater-insoluble at high temperature.

Lower critical solution temperature:Temperature that induces polymerprecipitation, i.e., phase separation.Textbook Of Biochemistry With ClinicalCorrelations, Thomas M. Delvin, Ed., 5 th Edn.,

2002

Polymers: Hydrophilic (Water-soluble)Hydrophobic (Water-insoluble)

Hydrogels: Network of hydrophilic polymersOrganogels: Network of hydrophobic polymers

T es of h dro els

.Covalent crosslinking

.Non-covalent crosslinking

Covalent and/orNon-covalent crosslinking

Ca++

Ch elatin ga g e n t

Calciumion

Sodium alginate

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Polymers: Hydrophilic (Water-soluble)Hydrophobic (Water-insoluble)

Hydrogels: Network of hydrophilic polymersOrganogels: Network of hydrophobic polymers

Ordinary Polymers & Hydrogels

Drug

Shrunken state- Squeezing- Trapping

Swollen state- Opening- Absorbing

Crosslink Precipitation Dilution

Smart Polymers & Hydrogels

Dissolution-PrecipitationSwelling-Deswelling

Respond to small changes in environmentalsignals by large changes in physicochemicalproperties

DegradationDegradation

Sol-gel phase transition Coil-Globule transitionShape transformation

PhysicalEnvironmental Stimuli

BiologicalStimuli

Chemical