05/03/2011

www.gupta-verlag.de/polyurethanes

Reacting capped prepolymers with blocked amines produces polyurea elastomers with low VOCs

Jay Johnston, senior development specialist, presented "Capped Prepolymers as Alternate Routes to Polyurethane Coatings, Adhesives and Sealants" as part of Education Track 2: Technical and Government Regulations.During his presentation, Johnston explained how capped polyurethane prepolymers can be utilized for additional purposes beyond their standard usage to flexibilize epoxy resins. While this traditional application has reduced brittleness, increased elongation and flexibility, and improved toughness and impact resistance of many epoxy coating formulations, capped polyurethane prepolymers can also be used to create products with useful properties without the addition of epoxy resins. In order for this to occur, Johnston explained, the capped polyurethane prepolymers are reacted with multifunctional amines to produce polyurea elastomers."By reacting capped prepolymers with blocked amines, formulators are also able to manufacture one-component, moisture-curing elastomers," said Johnston. He continued, "The resulting elastomers contain low volatile organic compound (VOC) levels and do not bubble when encountering wet environments."Johnston also discussed several two-component adhesive and sealant starting point formulations.

www.gupta-verlag.de/polyurethanes