16 Experiment 10: Stryofoam

https://www.csub.edu/chemistry/organic/manual/Lab8_ChromatographicAnalysis.pdf

https://web.stevens.edu/wit/research/samples/plipsy_organic_chemistry_lab_report.pdf

http://ocw.umb.edu/chemistry/organic-chemistry-i-lecture/tlcexperiment.pdf/at_download/TLCExperiment.pdf

https://elearning.cpp.edu/learning-objects/organic-chemistry/tlc/

ACS/Ron’s experiment:

PROJECT 17

PROPERTIES OF THE STYROFOAM CUP

OBJECTIVE: TO STUDY THE ASPECTS OF SYTROFOAM AS A CUP

learning points:

1. understand the use of sytrofoam and it’s properties
2. evaluate different approaches to re-cycle styrofoam

Styrofoam is composed of ninety-eight percent air, making it light weight and buoyant.  Because of its insulating properties and its buoyancy, it was adopted in 1942 by the United States Coast Guard for use as a six-person life raft.  The term is applied in a generic manner but it is a different material from the extruded polystyrene used for Styrofoam insulation. The Styrofoam brand polystyrene foam used for hobby crafts can be identified by its roughness and that it crunches when cut.  It is moderately soluble in many organic solvents.

What we commonly call Styrofoam, is actually the most identifiable form of foam or polystyrene packaging. Styrofoam is actually the trademark from the Dow Chemical Company, the technical name of the product is foamed polystyrene.  Polystyrene is made from petroleum products. Two widely used types of expanded polystyrene is EPS or expanded polystyrene and XPS or extruded polystyrene.  Both are made with polystyrene but have different manufacturing processes.

The XPS Styrofoam product may have little re-cycling potential due to contamination with food products and/or grease. The Dow Chemical Company introduced Styrofoam products to the United State in 1954.

Process for making Styrofoam products made:

1. Foamed polystyrene starts as small spherical beads that contain an expanding agent called a hydrocarbon.
2. The polystyrene beads are heated with steam, but as the expanding agent boils the beads soften and expand forty times their original size.
3. The expanded beads are left to cool down before being heated again. At this stage the beads are expanded within a mold.
4. The molds are designed in a variety of shapes depending on the desired end product: Styrofoam cups, cartons, wig stands, and more.
5. The beads completely fill the mold and also fuse together.
6. Styrofoam is about 98% percent air

Styrofoam is made from a petroleum origin product known as styrene. During a complex chemical process known as polymerization, the styrene is refined into a clear molten mass of polystyrene. If this material is left to cool, then it would become a hard plastic. This type of polystyrene comprises disposable eating utensils. However, before the polystyrene is cooled an agent which causes polystyrene to expand known as Hydrochloroflourocarbon142b is dissolved into the polystyrene under great pressure. The molten polystyrene is then extruded or forced through a narrow slot, and then allowed to expand under reduced pressure until it creates foam boards. From there, the boards can be cut into whatever dimensions are required. As a result, the finished product is known as extruded polystyrene foam or Styrofoam.

Styrofoam could become a major environmental problem if re-cycling of materials is not followed.  The world produces tons of Styrofoam each year. The fact that Styrofoam biodegrades slowly can add to the ecological impact.

SAFETY

Do not spill any of the solvents.  Do not breathe any fumes that emanate from the solvents.  Wear goggles and rinse hands profusely in water if any solvent makes contact.

Clean Up

Refer to the laboratory instructor as to where to dispose of solvents.  As always: return everything to its place, wipe your bench, lock your drawer, and return the key to the key cabinet.

PROCEDURE

1. Obtain two 150 ml beakers. Into separate beakers place 15 mL toluene and 15 mL of acetone.
2. Place a fragment of the Styrofoam cup into each and record your observations.

*Describe results of strip of cup in acetone.

*Describe results of strip of cup in toluene.

3. Dispose of these mixtures in the designated waste bottle.

To Determine Volume of Styrofoam material in the Cup

1. Weigh the intact dry cup. Record weight cup = __________
2. Tear off a strip of the cup and weigh that strip. Record weight strip = ________
3. Now place a known amount of water in a large graduated cylinder (but not

full to 100 mL).  Read the volume to tenths of milliliters.

4. Using a glass stir rod hold the small strip of (step 2) just below the surface of the

water and record the volume change from the initial volume (that will be the volume

of the strip).  Record volume of strip =  ________

5. The total volume of the cup =  Mass of cup     X    Volume of strip

Mass of strip

6. Dispose of remaining solvent in proper waste bottle.

ANSWER THE FOLLOWING QUESTIONS:

1. Which organic solvent dissolved the Styrofoam the quickest?

Did the Styrofoam leave any residue in the solvents?

In which solvent did a Styrofoam residue remain?

2. Of the two organic solvents you tested, which might be the best choice for re-cycling the Styrofoam?

Why did you make that choice?

3. What was the volume of the Styrofoam material in the piece? (show math)

What was the volume of the Styrofoam in the entire cup?  (show math)

4. Based on the volume of the cup material, why are Styrofoam materials a potential problem for landfills?