Preparation and characterization of electroless Ag plating on glass beads-expanded graphite/poly (vinyl chloride) electrical conductive composites

Electroless Ag plating was performed on surface of hollow glass beads (HGB) using a Pd-free and SnCl₂ free electroless Ag plating new process, then electroless Ag plating on glass beads (Ag-GB)-expanded graphite(EG)/poly(vinyl chloride)(PVC) composites were prepared by melt blending method. Surface morphology and structure of Ag-GB coating were characterized by SEM, EDS and XRD test methods. And the effects of Ag-GB and EG as composite fillers on the electrical conductive and mechanical properties of Ag-GB-EG/PVC composites were also investigated. The results show that the surface of pretreated HGB result in Ag layer deposition easily, the coating is more uniform and compact, and the mass fraction of Ag layer on the Ag-GB surface is 81.15%. When the mass fraction of Ag-GB is fixed to 15%, with the increase of EG mass fraction, the volume resistivity of the Ag-GB(15%)-EG/PVC composites decreases nonlinearly. When the mass fraction of EG is about 12%, which reaches the percolation concentration, whose volume resistivity is 2.18×10³ Ω·cm, meeting application requirement for antistatic PVC materials. Furthermore, when the mass fraction of EG is 12%, the volume resistivity of the Ag-GB(15%)-EG/PVC composites is equivalent to that of the Ag-GB(50%)/PVC composites, and the tensile strength of the Ag-GB(15%)-EG/PVC composites reaches the maximal value.