Organic precursor of EP/PU was prepared by epoxy resin which was polyurethane toughened

and then modified epoxy resin adhesive was synthesized using nano-silica as modifier.Microstructure of composite materials was observed by scanning electron microscopy(SEM).The results showed that the inorganic phase had well dispersed in the polymer matrix

and the polyurethane has formed the hole structure in the epoxy resin substrate.The mechanical properties

thermal stability and dielectric loss

dielectric constant of...