Characterizations of poly(ester imide) nanocomposites containing organically modified hectorite

Abstract

A series of poly(ester imide) (PEI) hybrid films containing ester linkages were prepared by reacting 2,6-dihydroxynaphthalene bis(trimellitic anhydride) and 4,4'-oxydianiline with varying organoclay contents by solution intercalation polymerization to form poly(amic acid)s. The thermomechanical properties, morphology, optical transparency, and gas permeation of the PEI hybrid films were examined for organically modified hectorite (STN) loadings ranging from 0 to 15 wt%. Up to a STN loading of 15 wt%, most of the clay was well dispersed in the PEI matrix, with only some agglomerated particles < 15 nm in size. Addition of small amounts of STN was sufficient to improve the thermomechanical properties. However, the optical transparency and barrier property of the PEI hybrids were almost constant irrespective of the increase in clay content from 0 to 15 wt%.