Comparative studies for the effect of dual- and mono-organic modifiers on the physical properties of polyimide-clay nanocomposite membranes

In this study, a series of nanocomposite membranes consisted of organic polyimide and organo‐modified clay were successfully prepared by an in situ polymerization through thermal imidization reactions using a dual‐ (i.e., CTAB/melamine) and mono‐organic modifier as swelling agent of clay mineral. A sequential comparative study was performed to investigate the effect of various feeding ratios of dual‐ and mono‐organic modifiers on the physical properties of as‐prepared samples. The as‐synthesized nanocomposite membranes were subsequently characterized by WAXRD and TEM. It should be noted that all the nanocomposite membranes prepared from a dual‐organic modifier system exhibited a better dispersion of silicate layers in PI matrices as compared with that of mono‐organic modifier system. Comparative studies for the effect of various feeding ratios of dual‐ and mono‐organic modifiers on the thermal stability, mechanical strength, molecular barrier properties, and optical clarity of PI‐clay nanocomposite membranes were performed with measurements of TGA, DSC, DMA, GPA, VPA, and UV–visible transmission spectroscopy, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008