The approach to the development of the composition and the requirements to the physicochemical and technological properties of binders used as the polymeric base for syntactic foams are formulated. The main advantages and drawbacks of the binders used for spheroplastic fabrication, such as epoxy, polyurethane, phenolic, and oligoester compounds, are discussed. The rheological properties and heat resistance of the polycyanurate binder developed at the All-Russia Research Institute of Aviation Materials are studied. The binder is characterized by long working life in the temperature interval up to 150°C. The results obtained and the properties of multilayer structures with the spheroplastic based on this binder show that the suggested polycyanurate binder is suitable for fabrication of spheroplastics.