Pharma

PET — Characterization of the packaging material

For identification of PET according to USP <661.1>, the sample should be heated twice to 280°C (1^st time at a heating rate of 20 K/min, 2^nd heating at 5 K/min) with a quick cooling in between.

After that, the evaluation result should be compared with the characteristic data of the reference material USP PET RS.

The present example shows the 2^nd heating of a 12 μm-thin film of PET (sample mass: 2.48 mg), measured using a heating rate of 10 K/min in Al crucibles and a nitrogen atmosphere. The glass transition (mid temperature) yields 81°C, the endothermal melting effect exhibits two peaks with the major one at 252°C.