Fabrication and characterization of the orientated MMT/PI composite films via relatively low magnetic field

Anisotropic cetylpyridinium modified magnetic montmorillonite/polyimide (CPC‐Fe 3 O 4 ‐MMT/PI) composite films were prepared based on CPC‐Fe 3 O 4 ‐MMT capable of exfoliation and magnetic‐field response via in situ polymerization and relatively low magnetic field adjustment (0.6 T) in the film casting followed by imidization. The stability of CPC‐Fe 3 O 4 ‐MMT during the in situ polymerization over flow shearing of the polymers and longtime stirring was evaluated by comparison the composition of CPC‐Fe 3 O 4 ‐MMT before and after polymerization via TG analysis and element analysis. Besides, the structural anisotropy of the produced CPC‐Fe 3 O 4 ‐MMT/PI composite films deriving from orientation of plate‐like CPC‐Fe 3 O 4 ‐MMT was confirmed by 1‐D and 2‐D XRD and SEM. The CPC‐Fe 3 O 4 ‐MMT/PI composite films with structural anisotropy exhibit gas permeation, optical and magnetic anisotropic properties which would widen the application fields of the composite films. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41224.