What is the fine-grained topic of the following text: Contemporary water-borne polyurethane coatings that promise significant lowering of VOCs and HAPs are not suitable for some DoD applications due to inefficient film formation and longer drying times when compared to solvent-borne coatings that render them unacceptable for multi-coat on-site applications and ambient cure conditions. Only return the topic.
Inefficiencies of Contemporary Water-Borne Polyurethane Coatings for DoD Applications