Core-shell expandable graphite @ aluminum hydroxide as a flame-retardant for rigid polyurethane foams

A kind of core-shell expandable graphite @ aluminum hydroxide (EG@ATH) as the halogen-free flame retardant for rigid polyurethane foams (RPUF) was designed. This is the first report to prepare encapsulation of expandable graphite with inorganic nanomaterials to increase the expandability. The as-prepared EG@ATH particles showed high efficiency of flame retardancy in RPUF, and improved interface adhesion between EG@ATH particles and RPUF, due to the pre-reaction of ATH layers with polyisocyanate.198