Polybutylene terephthalate adhesion on metals: A density functional theory investigation

We investigate the adhesion strength of poly(butylene terephthalate) or PBT on aluminum using density functional theory based energy calculations on periodic models. Instead of dealing with a bigger polymer system, we considered, as a first step, a small scale configuration to examine the key point of adhesion between PBT and Al surface. We placed the PBT monomer horizontally and vertically on aluminum surface. We also considered placing aluminum on top of the bulk PBT. By calculating the total energy of the system when PBT monomer approaches aluminum surface and comparing them with their energies when they are isolated, we obtain the binding energy of PBT on aluminum surface. The adhesion is stronger when the PBT monomer is oriented vertically than horizontally. Strong binding is also observed when the aluminum atom is placed on bulk PBT.