Zegui Yan, Ph.D.
Hexion Inc., Versatics Group
Zegui Yan has 15 years of industrial experience in polymer synthesis and application development for the coatings and adhesives markets. He holds a Ph.D. in Organic Chemistry from the University of Sunderland in UK.
Innovative Vinyl-Alkoxysilane Binders for Isocyanate-Free Protective Coatings
Two-component polyurethane (2K PU) systems are the most widely used topcoats for high-performance protective coatings. Nevertheless, environmental, market and cost pressures have led to the development of isocyanate-free alternatives to those systems. Moisture-curing topcoats based on acrylic- and epoxy-alkoxysiloxane resins have been increasingly used as isocyanate-free alternatives in protective coating applications. However, these alternatives have seen limited market penetration, due to an unfavorable cost/performance balance. This paper presents a new family of polymers, which combine vinyl (neo)esters and vinyl alkoxysilane monomers. Variation of process parameters, monomer composition and alkoxysilane levels yielded a series of vinyl alkoxyysilane polymers with solids content between 70 and 100%, and a wide range of attractive properties. Performance evaluation of 1K and 2K moisture-cure coatings based on this highly versatile isocyanate-free technology demonstrates that it brings fast hardness development, very long shelf life and high coating performance. These factors make these vinyl silane copolymers an attractive alternative to 2K polyurethanes and acrylic-alkoxysiloxanes for protective coatings.