Mechanical study of metallized polyethylene terephthalate (PET) films

Mechanical properties such as Young's modulus (Y), storage modulus (E'), glass transition temperature (T-g), tensile strength (sigma), and yield strength (sigma(y)) of metallized polyethylene terephthalate (PET) films have been measured using Dynamic Mechanical Analyser (DMA). Commercially available PET film thickness of 20 mu m has been used for metallization. Aluminiurn (Al) and lead (Pb) have been coated separately on PET films by vacuum thermal evaporation method to form metallized PET films. The T-g of AI-PET and Pb-PET films has been found to be 112.3 degrees C and 111.2 degrees C respectively whereas T-g of commercial PET film is 89.7 degrees C. The stress-strain curves of metallized PET films at room temperature and at different elevated temperatures have been taken which show significant temperature dependence. In particular, the yield strength shows a decrement with increasing temperature. (C) 2009 Elsevier B.V. All rights reserved.