A MARTINI Coarse-Grained Model of a Thermoset Polyester Coating

We hereby present a coarse-grained model of a typical polyester resin for coil coating applications. We validate the model via comparison with experimental data. The interactions between coarse-grained particles are described by the MARTINI force-field [Marrink et al. J. Phys. Chem. B 2007, 11, 7812]. Our model and molecular dynamics simulation protocols include the description of a hardener and the formation of cross-links between the hardener and the polyester resin. We perform experimental tests on the thermodynamic and mechanical properties of the system, and compare them with molecular dynamics simulations. The model estimates the glass transition temperature of the coating within 30 K of the experimental measurement. The model captures correctly the broadening effect of cross-linking on the glass transition, and on the temperature dependence of the elastic response of the polyester resin.