an introduction to polymers dr. sheppard chem 4201 fall 2014

An Introduction to PolymersDr. Sheppard

CHEM 4201

Fall 2014

Polymers

Natural vs. synthetic

Industries

What is a polymer? Monomer

Dimer

Oligomer

Polymer

Copolymer

Cl

+ + +

Crosslinked

Dendrimers

Structure

Linear

Branched

Copolymers

Properties

Structure

Size and MW

Density

Crystallinity

Strength

Biodegradability

Example: polyethylene

CH2

n

CH2 CH2 CH2 CH2 CH2

Polymer recycling

Polymer Classifications

Thermal Properties

Thermoplastics

Plasticizers

Thermoset plastics

Polymer Classifications

Uses Elastomers (rubber)

Fibers

Adhesives

Natural rubber

Polymer Classifications

Method of Synthesis

1. Chain-growth/addition polymerization

2. Step-growth/condensation polymerization

Polymerization Reactions

1. Chain-growth/addition Radical

Polymerization Reactions

1. Chain-growth/addition Acid (cationic)

Base (anionic)

Polymerization Reactions

2. Step-growth/condensation

Naming

Simple polymers:

CH2 CH2

Cl

n

n

nCl

Some Addition Polymers

Polytetrafluoroethylene (PTFE)

1,1-Dichloroethylene

Polypropylene (PP)CH2 C

CH3

H

CH2 C

Cl

Cl

C C

F

F

F

F

Some Addition Polymers

Acrylates

Poly(methyl methacrylate) (PMMA)

Poly(ethyl acrylate) (PEA)

Poly(2-hydroxyethyl methacrylate)

Cyanoacrylates

O

OH

acrylic acid

O

O

O

O

O

O

CH3

CH3

CN

R

O

O

CH3

OH

Some Addition Polymers

Rubber

Natural rubber

Neoprene rubber

Butadiene copolymers

Polyamides Nylon 6,6

Nylon 6

Some Condensation Polymers

NH

nO

Some Condensation Polymers

Polyamides Kevlar C C N N

O O

H Hn

Some Condensation Polymers

Polyesters Poly(ethylene terephthalate)

Other polyesters

O

OHO

HO

terephthalic acid

HO

OH

ethylene glycol

+

CC O

O

O O

n

Some Condensation Polymers

Polyurethanes Spandex

Other polyurethanes

Polycarbonates Lexan

Some Condensation Polymers

Some Condensation Polymers

Silicones (Siloxanes)Si

CH3

CH3

O

n

Applications of Polymers

Choosing a polymer Design Other factors

Mechanical/thermal properties Synthesis Body’s reaction to polymer Biodegradability

Polyglycolide (PGA), polylactide (PLA), and copolymers

Drug-polymer conjugate

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Biodegradable Polymers for Drug Delivery

Drug

linker

polymer