Molecular dynamics of laser ablation of a polymer coating

Large-scale molecular dynamics calculations have been carried out to simulate laser ablation on a polymer surface. The model consisted of a polyethylene chain with 400 CH₂ units placed on a polymer surface. A laser excitation was simulated by giving a small portion of the polymer chain a nonequilibrium momentum distribution. The excitation energy threshold for fragmentation of the polymers was found to be quite large, owing to the tendency of the system to transfer large amounts of vibrational energy along the chain.