Structure and properties of polymers modified by ion implantation

Thin films of oriented polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE) and polyamide (PA6) were modified by the implantation of 150 keV Sb⁺ ions to the fluences 10¹²–10¹⁵ cm⁻². The Sb depth profiles were determined by a standard Rutherford back-scattering technique and the range parameters were found to differ from the theoretical TRIM estimate. The thickness of the ion beam modified surface layer is about 150 nm for all polymers examined. Production of conjugate double bonds and polymer surface oxidation were proved by means of i.r. and u.v. spectroscopies. Surface polarity, obtained by goniometric measurements, is an increasing function of the implanted dose with only the exception of PA6 where a polarity decrease is observed. The measured temperature dependence of the sheet resistivity for PE, PP and PA6 do not correspond to the well known variable range hopping mechanism.