CHEMICAL APPROACHES TOWARD THE DEFINITION OF NEW HIGH-SOLID AND HIGH-PERFORMANCE FLUOROCOATINGS

Hydroxy bifunctional fluoropolyether oligomers (ZDOL) are presented su itable for use as resins or for the preparation of polyurethane, polye ster and polyether higher OH functionality resins. The synthesis proce dures are described and discussed, and the effect of fluorine content and resin structure on glass transition temperature T-g and viscosity of final resin is stressed. It appears that the highly fluorinated pol yether type resins, like the tetraolic derivative (TOL) and its mixtur es with ZDOL, are characterized by only one, extremely low T,and minim um viscosity values. Solvent-resin interactions and criteria for obtai ning compatibility with polyisocyanate crosslinkers are discussed, poi nting out the key role of hydrogen bonding. High solid coatings (solve nt content less than 30%) are obtained by curing with blocked aliphati c polyisocyanates, and a preliminary characterization of final materia ls based on their thermal transitions and mechanical properties is rep orted. (C) 1997 Elsevier Science S.A.