NMR Analysis and Consulting - Polymers

From What are Pop Bottles Made?
We drink soda pop every day from plastic bottles, with little thought of from what the bottles are made. This is a fairly easy analysis. We dissolve a 5-10 mg piece in trifluoroacetic acid-d (TFA -d) and run an 1H spectrum.

Spectrum of Pop Bottle
The TFA peak is at 11.5ppm. We have two fairly sharp singlets, one at 8.2ppm and the other at 4.9ppm. They integrate 1:1. The 8.2ppm peak is characteristic of terephthalate, the later of a polyester. This indicates polyethylene terephathalate.