The mechanisms of simultaneous solvent evaporation and film formation in high-solids thermoset coatings are considered. The relevant phenomena, chemical reactions, solvent diffusion and evaporation, gelation, vitrification, network mobility restrictions, and crosslinking, are quantified and a mathematical model for a curing film is presented, which does not violate the local volume balance. For model verification, a previous investigation with a polyisocyanate and a polyol in methyl amyl ketone solvent, catalyzed by an organotin compound, was selected. In contrast to earlier modelling studies, simulations can match and explain detailed experimental data. For exemplification, simulations are used to analyse the influence of the various rate phenomena on the behavior of the solvent-based polyisocyanate/polyol film.
|Journal||Journal of Coatings Technology and Research|
|Publication status||Published - 2010|
- Glass transition temperature
- Network formation
- Solvent trapping
- Crosslink density