Synthesis and applications of cyclic carbonate functional polymers in thermosetting coatings

Thermosetting coatings based on the cyclic carbonate-amine reaction are attractive since polyurethane coatings can be made without the use of isocyanates. Cyclic carbonate functional polymers were prepared via the free radical solution copolymerization of vinyl ethylene carbonate with vinyl ester monomers. The level of vinyl ethylene carbonate was varied from 10 to 50%. In order to develop an understanding of the kinetics of the reaction of cyclic carbonates with amines, kinetics of a number of amines were determined with a model cyclic carbonate, propylene carbonate. The kinetic information was used to help select appropriate amine crosslinkers and develop thermosetting coatings using cyclic carbonate functional polymers and oligomers. For screening of coating properties, clear coating formulations were applied to pretreated metal panels and cured at 80 degreesC for 45 min. A number of coatings were prepared to study the effect of amine, stoichiometry, solvent, and copolymer composition on the coatings properties. Coatings prepared had excellent solvent resistance, good gloss, and high pendulum hardness. (C) 2000 Elsevier Science S.A. All rights reserved.