Preparation and characterization of tapioca starch‐poly(lactic acid)‐Cloisite NA+ nanocomposite foams

Abstract

AbstractTapioca starch, poly(lactic acid), and Cloisite NA+ nanocomposite foams, with four clay contents (1, 3, 5, 7, wt %), were prepared by melt‐intercalation method. Selected structural, thermal, physical, and mechanical properties were characterized using X‐ray diffraction (XRD), scanning electron microscopy, differential scanning calorimetry, and an Instron universal testing machine, respectively. XRD results indicated that the 1 wt % nanocomposite foam did not show the characteristic basal reflection of the nanoclay. The 3, 5, and 7 wt % nanocomposite foams produced a mixture of intercalated and tactoid structures. The d001‐spacing of 3, 5, 7 wt % nanocomposite foams produced increases of 11.40, 11.15, and 10.67 Å, respectively, compared to that of the pristine clay. The morphological study showed that the nanocomposite foams exhibited a noticeably reduced cell size, more compact cells, and increased cell density. Increasing clay content caused a decrease in melting temperature (Tm). Bulk spring index and bulk compressibility were influenced (P < 0.05) significantly with the addition of different amounts of clay. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008