Preparation and Performance of Nano-hybrids Synthesized from Polyimide and Silica

Abstract

Polyimide (PI)-inorganic like silica hybrid films were successfully prepared to combine the good performances of silica like tensile modulus, thermal stability etc. into organic PI. Polyamic acid (PAA), precursor of PI, was prepared from 3, 3′, 4, 4′-biphenyltetracarboxylic dianhydride (BPDA), p-phenylediamine (PDA) and in-situ formed silica was formed into PAA from tetraethoxysilane (TEOS) through in-situ sol-gel process. The films were transparent and became translucent in presence of up to 10% inorganic contents. The chemical structures were characterized by Fourier transform infrared spectroscopy (FTIR). The morphology of the films was investigated by scanning electronic microscopy (SEM). Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), stress-strain tests and dynamic mechanical analysis (DMA) were used to evaluate the performances of the films. The results indicated that the glass-transition temperatures (T_g) and decomposition temperatures of the PI-silica hybrid films were higher than those of pristine PI. Tensile modulus, tensile strength of PI increased prominently in presence of small amount (1%) of silica in PI-silica hybrid.

Keywords: Polyimide; Hybrid; Sol-gel process.

© 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.

DOI: 10.3329/jsr.v2i1.2733                 J. Sci. Res. 2 (1), 99-107 (2010)