Chemical Changes Created by High Energy Ions in Polyethylene

Argon and oxygen ions were accelerated with energies of 50 to 150 keV and rastered across high density polyethylene. The free radicals formed in the ion-implanted polyethylene were studied using an electron spin resonance spectrometer. The free radicals formed were stable in air and even survived solvent separation of the undamaged polymer from the ion damaged polymer. Chemical characterizations indicated that pregraphitic or graphitic-like particles are formed with defect sites which are, in effect, free radicals stabilized by a polyaromatic system.