Self-assembly of zinc hydroxystannate on amorphous hydrous TiO₂ solid sphere for enhancing fire safety of epoxy resin

Zinc hydroxystannate (ZHS) was fabricated on the surface of amorphous hydrous TiO₂ solid spheres (AHTSS) via a layer-by-layer method for improving the fire safety of epoxy resin. AHTSS@PEI@ZHS was prepared by self-assembly of AHTSS, PEI and ZHS. The well-organized fabrication process was proved by TEM, XPS, XRD and SEM tests. TG results illustrated that the incorporation of AHTSS@PEI@ZHS show a higher residue compared with the addition of AHTSS or ZHS alone. In addition, AHTSS@PEI@ZHS filled EP composites exhibits improved flame retardancy and smoke suppression properties evaluated by cone calorimeter test. TG-IR results also indicated that the catalytic labyrinth structure of AHTSS@PEI@ZHS can effectively decrease the permeation of volatile organic compounds, thereby improving the fire safety of EP resin.