Polyimide/amine-functionalized cellulose nanocrystal nanocomposite films

In this study, modified cellulose nanocrystals (AF-CNCs) with (3-aminopropyl) triethoxysilane (APTES) were used to prepare poly (amicacid)/AF-CNC nanocomposite films via spin coating. To convert poly (amic acid) into polyimide (PI), the films were thermally imidized after spin coating. The effects of AF-CNC content on the tensile properties, thermo-mechanical properties, optical transmittance, morphology and barrier properties of PI/AFCNC nanocomposite films were investigated. With increasing content of AF-CNC from 0 wt% to 3 wt%, tensile modulus and storage modulus of PI/AF-CNC nanocomposite films increase without decrease in their optical transmittance. The water vapor transmission rate and tan delta peak height of PI/AF-CNC nanocomposite films decrease with increasing AF-CNC content from 0 wt% to 3 wt%. For comparison, PI/CNC nanocomposite films with 2 wt% of unmodified CNC were also prepared. PI/AF-CNC (2 wt%) nanocomposite films show better mechanical and physical properties than PI/CNC (2 wt%) nanocomposite films.