本研究では，樹脂の促進劣化を想定した簡易的な劣化予測手法の確立を目的として，初期酸化を高感度に検出可能な化学発光測定装置を用いて，樹脂の劣化評価方法の検討を行った．試料には，化学発光装置内や恒温槽内で劣化度を調整したポリプロピレンを用いた．劣化樹脂中に蓄積した過酸化物の相対量を把握することで，樹脂の劣化度を評価する手法の検討を行い，この手法により評価した過酸化物蓄積速度を用いて劣化予測を行った．130-150°Cにおける過酸化物蓄積速度から60°Cにおける劣化の進行度合いを予測したところ，従来から利用されている酸化誘導時間による予測よりも精度の高い予測が行えた．

Polyethylene (PE)-based nanocomposites were developed using PE-grafted SiO₂ (PE-g-SiO₂) nanoparticles, which were prepared by grafting terminally hydroxylated PE having different molecular weights. The obtained PE/PE-g-SiO₂ nanocomposites were characterized in terms of the nanoparticle dispersion, the crystallization, and the tensile properties in a comparative way to pristine PE, PE/SiO₂ nanocomposites and previously reported polypropylene (PP)/PP-g-SiO₂ nanocomposites. Similarly to the PP grafting, the PE grafting markedly improved the dispersion of the nanoparticles in the corresponding matrix and accelerated the crystallization. The addition of 5.0wt% of PE-g-SiO₂ led to increments of the Young’s modulus and tensile strength over pristine PE by 23% and 11%, respectively, while the addition of unmodified SiO₂ hardly improved these properties. The reinforcing mechanism in the PE/PE-g-SiO₂ nanocomposites was also discussed.