what is a polymer? withrow university high school may 2008

What is a Polymer?

Withrow University High School

May 2008

Definition

The word polymer comes from the _________ language.

poly - mer

many - parts

So, polymer means “__________”.

A Polymer Molecule

• A polymer is a _________ ______________.• This giant molecule is a long _________ of

______________ _____________ units. • These repeating units are called ___________. • A polymer molecule are made up of ________ of

monomers.

M M M M M M M M

Natural PolymersCotton from plants is a natural polymer and is used to make clothing

Silk from silk worms is used to make cloth

Wood is a natural polymer used for paper

Natural latex from rubber tree is a polymer

Rubber can be used to make tires

or rubber bands!

Crustacean shells are made of chitin, a natural polymer

“Carbs” like spaghetti are natural polymers

Proteins from eggs and other foods are also

natural polymers

Man-Made (Synthetic) Polymers

Polyethylene is used to make plastic sandwich bags

Compact Discs are made from synthetic polymers such as polycarbonate

Milk jugs are made from the synthetic polymer

polyethylene (HDPE)

Polystyrene is used to make Styrofoam cups and cd cases

Soda bottles are made from polyethylene terephthalate

(PETE)

Synthetic polymers are used to make specialty athletic

clothing using polymer such as Polyester, Nylon, Lycra

or spandex

Can you think of any other types of man made polymers and

their uses?

Symbol

• The pictures below represent a polymer chain. (draw it)

• The “M” stands for ___________________.

Elasticity makes a ball bouncy• An elastic object is able to change shape

and return to its original shape.

Floor

4. The ball bounces back up.

2. The ball changes shape when it hits the floor.

3a. The ball returns to its original shape.

3b. The ball pushes off the ground

1. The ball drops

What’s going on inside?

• The molecules stretch when a force is applied.

• When the force is removed, the molecules return to their original shape.

Polymers make the best elastics

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

A polymer chain at rest

A force pulls and stretches the polymer chain.

A force pulls and stretches the polymer chain

When the force is removed, the polymer chain goes back to its original shape, as long as it was not stretched too much! That would cause the bonds to break.

Example Monomer

• Mono = “One” Put it together with mer to get?–

• Tiny molecular unit that can chemically combine by bonds with other monomers to form a chain called a Polymer

Ethylene monomer molecule (C2H4)

Polymer Synthesis• combine chemically through

covalent bonds to form long chain molecules.

• For the double bond between the carbons is ‘opened’ up and attached to another atom of an ethylene monomer and the process continues as the molecule grows in size.

• Polyethylene (PE)– Plastic bags, milk jugs,

sockets for hip joint replacements, etc.

• Polyvinyl chloride (PVC)– Piping, house siding, turntable

records, etc.

• Polyvinyl Acetate (PVA)– Glue, binder for making

sheets of paper, binder for paints

How to Represent Polymers

[ ]n C – C

H H

H H

[ ]n C – C

H Cl

H H