Colorless Polyimide Nanocomposite Films With Pristine Clay: Thermal Behavior, Mechanical Property, Morphology, and Optical Transparency

Polyimide (PI)/clay hybrids were synthesized using the in situ solution intercalation method via poly(amic acid). The Na ion-exchanged clays Na+-saponite (SPT), Na+-mica (Mica), and Na+-montmorillonite (MMT) were used for the intercalation of PI polymer chains. Our dispersion results show that pristine SPT is more easily dispersed in a PI matrix than MMT or Mica. PI nanocomposites were prepared with various SPT contents to examine the variations with SPT content in the range 0-1 wt% of the thermomechanical properties, morphology, and optical transparency of the nanocomposites. The PI films have excellent optical transparencies, and are almost colorless. However, the optical transparency of the PI hybrid films decreases slightly with increases in the clay content. We also examined the relationship between the properties and clay content of the PI hybrid films using wide-angle X-ray diffraction (XRD) measurements, electronic microscopy (SEM and TEM), and universal tensile machine (UTM). The color intensities of the PI films were evaluated with a spectrophotometer. POLYM. ENG. SCI., 49:1357-1365, 2009. (C) 2009 Society of Plastics Engineers