Relating the mechanical properties of UV-cured coatings to the molecular network - A new approach to predict the cross-linking of coatings

A new approach to simulate the cross-linking reaction of UV-cured coatings and to generate realistic atomistic model structures in dependence of the formulation and the ambient conditions has been developed. With these models, the mechanical properties of UV-cured coatings can be related to the molecular network. At first, an extensive experimental characterisation of the relevant coatings was performed to parameterise and validate the simulation approach. Additionally, atomistic model structures of coating components were prepared and optimised via molecular mechanic methods. Using these as a basis, model structures of the un-cured coatings were generated according to the formulation. Afterwards, the relevant reaction steps were identified and a corresponding reaction scheme was established. With this, the energetics of the relevant reactions was calculated via density-functional theory (DFT) delivering the reaction probabilities and velocities of the polymerisation. For the simulation of the polymerisation of the UV-cured coatings, a crosslinking algorithm corresponding to the derived reaction scheme was implemented into a molecular dynamics code. Finally, model structures of the cured coatings were generated and could be related to the mechanical properties of the coatings.