Structure of Matter

3. Each of the more than 100 elements of matter has distinct properties and a distinct atomic structure. As a basis for understanding this concept:

3b. Students know that compounds are formed by combining two or more different elements, and that compounds have properties that are different from their constituent elements.

3d.Students know the states of matter (solid, liquid, gas) depend on molecular motion.

3e.Students know that in solids the atoms are closely locked in position and can only vibrate; in liquids the atoms and molecules are more loosely connected and can collide with and move past one another; and in gases the atoms and molecules are free to move independently, colliding frequently.

Procedure:

Polyurethane A and polyurethane B are mixed
exothermic reaction foam is formed massive amount...one capful used in video demo.(usually used to insulate homes, or make flotation devices)

1. Let foam cool 5 min
2. Squeeze cup until foam comes out in a big chunk
3. Apply eyes or other accessories as desired with the gnome, what used to be the cup is now the hat, and all that over flow is the beard.
   
   
   Materials:

• Poly A (polyether alcohol)
• Poly B (isocyanate) = catalyst to make poly A into long chain polyeurethane molecules
• Cup
• Stirrer
• Eyes if you want to make gnomes

Questions:

Applications to everyday life:

Questions:

1. List three chemical properties of these chemicals before they are mixed.

2. List two physical properties of these chemicals before they are mixed.

3. This chemcial is packaged commercially in a product that shoots out of a can, kind of like very thick spray paint. Homeowners spray the wet foam into cracks in walls and around window and doors to prevent heat loss in the winter and heat gain in the summer. Think of three other possible uses for this product.

4. This reaction is defined as exothermic. Based on your observation would you say that this experiment releases heat or absorbs it?

Applications to everyday life:

This type of foam is used to insulate homes and buildings, pack delicate equipment for shipping, and it is used for flotation devices such as docks, life preservers, and buoys.

Polyurethane foam can be purchased through your science supply companies or through your local hardware store. We paid $10.88 for a can of polyurethane insulation but it did not have the same two reactants that come in the kit. It was an all in one spray.

If you were to purchase the lab kit, you would need one oz of each polymer per group. (Approx. 32 ounces or one quart of each.) The cost of 1 quart of Ploy A and one quart of Poly B is listed as $23.95 each. (a total of 47.90 plus tax and shipping)

The Chemical Reaction:

The two chemicals react with each other. Poly B (isocyanate) acts as a catalyst on the poly A (polyether alcohol) to form long polyurethane molecules. As this occurs heat is generated and carbondioxide gas is released. Some of the gas is released into the air and some is trapped in the polyurethane as it expands. The polymer will dry and harden in the air.

References & Links:

Foam Gnome Sound Absorption Products

Video Depicting:

Foam Insulation

Applied to Attic

Making Surfbaords