Abstract: Disclosed is a composite comprising from about 50 wt. % to about 97 wt. % of a thermoplastic resin, wherein the thermoplastic resin comprises a polyester; and from about 3 wt. % to about 15 wt. % of a carbon-based filler, wherein the carbon-based filler has a primary surface area of from about 500 to about 1000 m2/g, wherein the composite exhibits a dielectric constant ?? of between 5 and 30 and a dissipation loss ?? of between 0.5 and 45, measured at frequencies between about 10 and about 120 GHz. A molded sample of the composite exhibits a percent reflected power measured in transmission mode of at least 15% when observed according to a Free Space method at frequencies from about 75 GHz to 110 GHz.

Abstract: Disclosed is a composite from about 50 wt. % to about 90 wt. % of a thermoplastic resin, wherein the thermoplastic resin comprises a polycarbonate polysiloxane copolymer; and from about 10 wt. % to about 50 wt. % of a carbon-based filler. The composite exhibits a dielectric constant ?? of between 5 and 20 and a dissipation loss ?? of between 0.1 and 6, measured at frequencies between about 10 and 120 GHz.