Structural modifications of swift heavy ion irradiated PEN probed by optical and thermal measurements

• The present paper reports the effect of swift heavy ion irradiation on Polyethylene Naphthalate (PEN).
• Swift heavy ion irradiation introduces structural modification and degradation of PEN at different doses.
• Lower irradiation doses in PEN result in modification of structural properties and higher doses lead to complete degradation.
• Strong correlation between structural, optical, and thermal properties.

The effects of swift heavy ion irradiation on the structural characteristics of Polyethylene naphthalate (PEN) were studied. Samples were irradiated in vacuum at room temperature by lithium (50 MeV), carbon (85 MeV), nickel (120 MeV) and silver (120 MeV) ions with the fluence in the range of 1×1011–3×1012 ions cm−2. Ion induced changes were analyzed using X-ray diffraction (XRD), Fourier transform infra red (FT-IR), UV–visible spectroscopy, thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. Cross-linking was observed at lower doses resulting in modification of structural properties, however higher doses lead to the degradation of the investigated polymeric samples.