|
Unknown Polymer Identification prepared by Kenneth Kauffman |
|
|
Background:
You currently work for a
multi-division corporation in their maintenance engineering department. On one of the specialty machines utilized in
the processing division, a small plastic piece has failed. You've been asked to replace it. Kauffman Ltd. manufactured the original
part. However, the company has since
gone out of business and you have been unsuccessful in finding the
specifications for the part in your company's files.
Your supervisor and you
agree that the part is most likely one of five very common polymers:
polyethylene
polypropylene
polystyrene
polycarbonate
poly(vinyl chloride)
Since your company produces
each of these polymers, you have samples of each on hand. You also have access to an R&D lab with
some basic equipment, which includes some of the following equipment (prior to
the experiment, your teaching assistant will tell you which equipment):
- a heater at 140'C
- a heater at 220'C
- a flame source
- standard solutions of density 1.00 g/cm 3
- standard solutions of density 1.05 g/cm 3
- insulated cups
- thermometers
- an ice bath
- a squirt bottle of acetone
- samples for hardness testing
- samples for testing the tensile strength
Procedure:
Using your samples of the
known polymers, develop a series of tests using the above equipment which will
conclusively identify a given sample of polymer. After you have done the preliminary tests and
you know the results of each test, develop a flow sheet which will allow you to
conclusively identify the polymer. Your
final flow sheet should look similar to the basic outline shown below (not
necessarily exactly like this):
UNKNOWNS
Prelab:
Your prelab
should consist of physical and chemical properties which will allow you to
predict the results for each test you do before you conduct each test. You should also have experimental procedures written
for each test you will do BEFORE you show up.
You have the equipment available.
Now, you need to determine how to do the tests.
Report:
For this experiment, the
most important components of the report (by far) will be your background
section, your experimental procedures, and the flow chart which you
develop. The background section should
contain descriptions of each of the key properties you utilized, key equations
which were manipulated so you could utilize the data you collected, and
background information on common uses of each of the polymers.
Polymer Identification Lab:
Objective:
Commonly, it is desirable to
know what type of polymer is present in a given situation. Often, the easiest way to do this is by conducting
some basic observational tests. Through
this experiment, you will develop a series of tests which will allow you to
distinguish between various polymers.
Procedure:
In the first part of the lab,
you will be given access to various known standards of polymers. Using these standards, you are to design a
series of tests which you can carry out to determine the composition of an
unknown. The unknown may contain any
single polymer or a mixture of the two.
You may use anything in the
lab that you desire for the experiments so long as it does not pose a health
hazard to yourself or the other people working in the lab. Before using any chemicals or equipment,
consult with your T.A. to ensure that no hazard exists.
Report:
You should cover in your
report how you came upon the procedure you developed, how your procedure works,
and what the definitive tests are. Also
discuss the properties of each polymer which you measured. In addition, find relevant data on the
approximate usage of each of the polymers tested.
