Surface modification of ethylene-norbornene copolymer by irradiation with N4+ ion beams

The modifications of copolymer of ethylene and norbornene induced by irradiation with 60 keV N4+ ions to the fluencies of 1.0 × 1016 ions cm−2 have been investigated using DSC, TGA, UV-spectroscopy, direct current surface resistivity and impedance measurements. The measured heat and thermal properties reveal remarkable stability against degradation. Copolymer properties studied at low electric field strengths were directly related to the modified molecular structure. The decrease in electrical resistivity was mainly attributed to conjugated double bond formation observed by ultraviolet spectroscopy. AC conductivity and capacitance obtained from the real and imaginary part of admittance varies with frequency. The movement of charge carriers may be related to relaxation phenomena in the material and is similar to those observed in many amorphous semiconductors.