The purpose of this experiment is to use FTIR spectroscopy to compare and identify different popular brands of plastic wraps. You will be given a sample of one of these wraps (Handi Wrap, Kroger Plastic Wrap, Glad Wrap, Reynolds Plastic Wrap, and Saran Wrap).

Your lab book introduction should therefore, include:

• the theory behind infrared absorption spectroscopy, especially as it relates to FTIR.
• information about the operation of an infrared absorption spectrometer, with diagrams of its internal schematics, and a short description of how each of the following parts works:
  1. light source
  2. interferometer
  3. detector
  4. recorder/analyzer

Procedure:

Cut a small piece of the plastic wrap and tape it across the sample holder in the FTIR. Run a scan and then use the Omnic library and determine the identity of the sample.

Results and Discussion:

Summarize the types of bonds present in your sample. Decide which one of the samples is your plastic wrap. Relate the different groups in the molecule to the different peaks seen.

Obtain a copy of the spectra for the other four samples and do the same thing.

What peaks do the spectra have in common? What peak(s) are found only in one or two of the samples?

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Polymers that make up Common Brand-Name Plastic Wraps

Handi Wrap Kroger Plastic Wrap Glad™ Wrap	polyethylene (PE) (ethene monomer)
Reynolds Plastic Wrap	polyvinyl chloride (PVC) vinyl chloride (chloroethene monomer)
Saran™ Wrap	copolymer of vinyl chloride and vinylidene chloride (1,1-dichloroethene) monomers

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