POLYMERSPOLYMERS, (a more acceptable term than

plastics”)The one area of

chemistry in which this country leads the rest of

the world.

poly = manymeros = parts, units

then, polymer = many parts

monomer --------------> p-o-l-y-m-e-r

The first “recorded” polymer:

Klatte didn’t know what he had . . . but

he wrote it up in his lab notebook!

Some terms to remember:Some terms to remember:Addition (chain growth) polymer

Condensation (step growth) polymer

Thermoplastic polymer

Thermosetting polymer

Syndiotactic polymer

Isotactic polymer

Atactic polymer

Co-polymers

ADDITION POLYMERSADDITION POLYMERSalso called also called “chain growth”“chain growth” polymers polymers

All parts of the monomer

are retained in the polymer.

Nothing is lost.

The monomers simply join to each other. – something like this:

SomeSome well-known addition polymers:

Additional “Addition” polymers

Note the two groups on the vinyl carbon . . .

Note the position of the substituent on the vinyl carbon . . .

Ways to catalyze polymerization:

A Radical has an “odd” or “unpaired” electron, but NO

CHARGE . . .

Electrons pair to either side, forming covalent bonds.

ANION (negatively charged) catalysts .

Anions “push” the negative electron pairs ahead.

CATION (positively charged) catalysts.

Cations “pull” negatively charged electron pairs toward themselves.

CONDENSATION POLYMERSCONDENSATION POLYMERSalso called also called “step growth”“step growth” polymers polymers

Small molecules are lost between units.

POLYAMIDESPOLYAMIDES

Nylon 6,6 and Nylon 6

The “NYLON ROPE”“NYLON ROPE” trick . . .

POLYESTERSPOLYESTERS

DACRONDACRON, a polyester

We are grateful for wrinkle-free fabrics; -- no starching; no ironing!

KODELKODEL, another polyester

Used to make fabric, tire cord; Mylar film in magnetic recording tape. Aluminized Mylar in Echo satellite, a giant reflector

orbiting the earth.

So far, what you have seen are linear polymers; the product of

two-point chain growth.

Linear polymers are usually

“thermoplastic” polymers.

They soften with heat, and can be “re-molded” if the product is not

perfect.

Three-point chain growth gives rise to cross-linked polymers.

These are usually “thermosetting” polymers.

They do NOT soften with heat.

If the final product is not perfect, it goes into the scrap pile.

1,3-butadienes can undergo 1,4 addition

..leaving a double bond for cross-linking.

COPOLYMERSCOPOLYMERS consist of polymerizing together two or more different monomers

The monomers need not be alternating, but may be combined in various configurations.

Some other interesting polymers:

A tough ABS polymer

Glyptal resin

Polycarbonates

Polyurethanes

Three different monomers in an interesting co-polymer.

An extremely durable high-impact polymer:

NFL helmets, pads, TV & radio chassis, etc.

Glycerol offers THREE points for chain-growth; leading to a cross-

linked polymer

Glyptal resin makes a strong, solid polymer matrix for electronic parts. It has remarkable

strength and rigidity.

A “transesterification” with anester of a “hypothetical acid”.

Many “clear, colorless” soft drink bottles

are polycarbonates.

Urethane, another ester of a “hypothetical acid”.

Alcohols and phenols react with isocyanates, yielding “urethanes”.

Again, each reactant has 2-point chain growth

Volatile materials (Freon 11) added produce bubbles, yielding polyurethane foam.

Glycerol can give cross-linking. Bisphenol A gives a different polyurethane.

PhenolPhenol reacts with formaldehydeformaldehyde in dilute base . . .

to give hydroxymethyl groups in the

2 -, the 4- and the 6 – positions . . .

Further condensation leads to a cross linked polymer . . .

known as BakeliteBakelite, one of the oldest commercial plastics

2,4,6-triamino-S-triazine undergoes a similar reaction with formaldehyde.

The polymer: “Melmac” was the early “cafeteria dishware”.

An interesting research possibility:

Then, why not with amines, also . . .

An interesting “cyclization” reaction:

. . . taken from an early Hiskey & Jung (or Jung & Hiskey) publication in the JACS. . .

. . . leading to additional research possibilies . . .

Since pABA cannot “back-bite”, the chain must grow linearly . . .

Quick review: you should know:• Addition (chain-growth) Polymer

• Condensation (step-growth) Polymer

• Thermoplastic Polymer

• Thermosetting Polymer

• Isotactic Polymer

• Syndiotactic Polymer

• Atactic Polymer

• Co-polymer