Irradiation effects in high-density polyethylene

Using molecular dynamics simulations, we have studied the irradiation effects in high density polyethylene. We found that the governing reactions were chain scissioning and generation of free radicals, whereas cross-linking and recombination of chain fragments was rare. We also determined the threshold energy for creating defects in the polyethylene lattice as a function of the incident angle. Our analysis on the damage threshold energy shows that it is strongly dependent on the initial recoil direction and on average two times higher for the carbon atoms than for the hydrogen atoms in the polyethylene chain.