Preparation and Characterization of Rigid Polyimide-Clay-Polydimethylsiloxane Hybrid

Abstract

A series of polyimide (PI)-clay-polydimethylsiloxane (PDMS) hybrid films were successfully prepared by using two different reactions, a sol—gel reaction of diethoxydimethylsilane and imidization of polyamide acid (PAA) prepared from 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA), in the presence of 2 wt% of organically modified montmorillonite. X-ray diffraction of the hybrid films indicated that the clay layers were exfoliated and dispersed into PI. Scanning electron microscopy was used to confirm the dispersion of PDMS and to measure the particle size of the PDMS. Thermogravimetric analysis, differential scanning calorimetry, viscoelastic analysis and stress— strain tests were used to evaluate the performance of the hybrid films. The addition of small amount of PDMS was found to overcome the brittle problem of PI-clay nanocomposites, and the PI-clay-PDMS hybrid showed excellent thermal and physical properties.