• blends;
  • clay;
  • free-volume properties;
  • high-density polyethylene;
  • nanocomposites;
  • polyamide 6


Two type of nanocomposites—an immiscible blend, high density polyethylene/polyamide 6 (HDPE/PA-6) with organomodified clay, and a compatibilized blend, high density polyethylene grafted with acrylic acid/PA-6 (PEAA/PA-6) with organomodified clay—were prepared via melt compounding. X-ray diffraction and transmission electron microscopy results revealed that the clay was intercalated and partially exfoliated. Positron annihilation lifetime spectroscopy has been utilized to investigate the free-volume hole properties of two type of nanocomposites. The results show a negative deviation of free-volume size in PEAA/PA-6 blend, and a positive deviation in HDPE/PA-6 blend, and I3 has a greater negative deviation in compatibilized blend than in immiscible blend due to interaction between dissimilar chains. For nanocomposites based on polymer blends, in immiscible HDPE/PA-6/organomodified clay system, the variation of free-volume size with clay content is not obvious and the free-volume concentration and fraction decreased. While in the case of compatibilized PEAA/PA-6/organomodified clay nanocomposites, complicated variation of free-volume properties due to interactions between two phases and organomodified clay was observed. And the interaction parameter β shows the interactions between polymers and organomodified clay. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2463–2469, 2006