Novel Polyimide/Silica Nano-hybrids via In-situ Polymerization: Synthesis, Characterization, and Properties

A silicon-based aromatic polyimide containing pendent aryl rings was synthesized by solutionpolycondensation of a silicon-containing diamine with 4,4’-hexafluoroisopropylidene)diphthalic anhydride (6-FDA). The related nano-hybrids were synthesized by insitupolymerization, nano- hybrid materials were produced by incorporating silica nanoparticles into poly(amic acid) solution. Reaction was carried out with or without coupling agent and the results were compared.3-Amino propyl triethoxysilane (APTES) was used as coupling agent for modification of the chain ofpoly(amic acid) and enhancing the compatibility between PI and silica network. The structures of thesynthesized materials were identified with FT-IR, EDAX. The morphology of these hybrid systems wereinvestigated by SEM, AFM and XRD analysis. Thermal properties of the nano-hybrids were evaluated byTGA, and DMTA techniques. The optical constants (n and k) and dielectric parameters (ε and έ) werecalculated from IR reflection spectra by employing the Kramers-Kronig dispersion relations.

Keywords:

polyimide , nano-hybrid , silica network , in-situ polymerization