A series of composite materials were prepared using conductive fillers of mixed-spun felts of metallic copper or nickel coated polyacrylonitrile (PAN) fibers /polyethyleneterephthalate (PET) and phenol resins. Their shielding effectiveness (SE) to electromagnetic interference (EMI) and thermal stability were examined and the following results were obtained. Cu series samples revealed shielding effectiveness to EMI both magnetic and electric fields. In the Ni series samples relatively small SE were observed in the electric field but not in the magnetic field except 800MHz region. The SE of the Cu series samples slightly increased with increase in content of the metal in the composites. Thermal treatment of the Cu series samples increased the SE in contrast with metallic short fiber/thermoplastic composites. Keywords: Electromagnetic interference (EMI), Shielding effectiveness (SE), Composite materials, Cu or Ni coated polyacrylonitrile (PAN) fibers, Thermal treatment

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It was found that Nation^® and Nafion^® SAC-13 which is coated with 20vvt % of Nafion on silicagel act as the flame retardant for polycarbonate (PC). In this study, the thermal decomposition of PCs containing both additives was investigated to clarify the interaction between polymer and additives using TGA and TG-MS. Potassium nonafluorobutanesulfate (NFBSAK) and polytetrafluoroethane (PTFE) were also used as reference materials. It was confirmed that NFBSAK and PTFE contribute to increase the amount of carbon layer and to accelerate the rate of decarboxylation, respectively. Similar result was obtained even in the case of thermal decomposition of PC with Nafion^® or Nafion^® SAC-13. It was also found that the efficiency of decarboxylation is strongly dependent upon the distribution of sulfonic acid in the resin.

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