Modification of polyethylene terephthalate by proton irradiation

Abstract

Polyethylene terephthalate (PET) films were irradiated with 3 MeV proton beams at different fluences. The microhardness, electrical, thermal and structural studies were carried out using microhardness tester, LCR meter, thermogravimetric analysis (TGA) and FTIR spectroscopy. Vickers' hardness has been observed to increase with the fluence. The true bulk hardness of the film was obtained at loads greater than 400 mN. The AC electrical conductivity is practically unaffected by irradiation up to a frequency of 10 kHz, but it is found to increase exponentially at a frequency of 300 kHz. The loss factor and dielectric constant are observed to change appreciably with the fluence. It is observed that there is no significant change in the stability of the polymer up to the fluence of 10¹⁴ ions cm⁻² as revealed by TGA and FTIR spectroscopy.

Keywords:

• Polyethylene terephthalate
• FTIR
• Hardness
• Electrical conductivity
• Thermal degradation

Acknowledgements

The authors are thankful to the operating staff of Cyclotron, Department of Physics, Panjab University, Chandigarh and to The Head, Department of Physics, S. P. University, Vallabh Vidyanagar for providing their laboratory facilities and ABS Bayer, Moxi for providing thermal analysis facilities. Financial support given by NSC, New Delhi is gratefully acknowledged.