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  • 1 University of Tsukuba Institute of Applied Physics Tsukuba, Ibaraki 305-8573 Japan E-mail
  • | 2 High Energy Accelerator Research Organization (KEK) Radiation Science Center Tsukuba, Ibaraki 305-0801 Japan
  • | 3 the Chinese Academy of Sciences State Key Laboratory of Engineering Plastics, Institute of Chemistry Beijing 100080 P.R. China
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Positron lifetime spectra were measured as a function of the time for metallocene polyethylene (mPE), poly(methyl methacrylate) (PMMA), polyamide (PA), and polycarbonate (PC). A decrease in o-Ps intensity with the elapsed time was observed in mPE and PC measured at room temperature and in PMMA measured at 225 K. Formation of free radicals has been supposed to be one of the causes of this effect. The effect of maleic-anhydride (maH) grafted copolymers and its ionomers in mPE/PA blends was also studied. The change in the positron lifetime distribution with increasing maH and the ionomer content revealed an enhanced interaction between mPE and PA phase and the decrease of dispersed mPE particles, which reflected good compatibility of the blend.