Morphology and electrical properties of carbon‐black‐filled poly(ϵ‐caprolactone)/poly(vinyl butyral) nanocomposites

Abstract

AbstractThe morphology of poly(ε‐caprolactone) (PCL)/poly(vinyl butyral) (PVB)/clay nanocomposites was studied as a function of a small amount of amorphous PVB by polarized optical microscopy. The band spacings of PCL spherulites in PCL/PVB/clay nanocomposites decreased with increasing PVB content, and this indicated that increasing the PVB content shortened the period of lamellar twisting. The electrical properties of PCL/PVB/clay nanocomposites containing carbon black (CB) were also measured as a function of the PVB content. For samples with the same CB content, the intensity of the positive temperature coefficient (defined as the ratio of the peak resistivity to the resistivity at room temperature) of the nanocomposites increased as the PVB content increased. The change in the positive temperature coefficient was related to the morphological differences (i.e., the period of lamellar twisting) in the nanocomposites. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1022–1031, 2003