Syntehesis, characterization and electrorheological properties of polyindene/montmorillonite nanocomposites

In this study, first polyindene (PIn) was synthesized using FeCl3 as an oxidizing agent. Then, natural bentonite was enriched and content of Na-Montmorillonite (Na-MMT) increased. Cation exchange capacity of Na-MMT was determined as 76 meq/100 g clay by using methylene blue test. An organo-montmorillonite (O-MMT) was prepared from Na-MMT by cetiltrimethylammonium bromide (CTMAB) quaternary ammonium salt. Further, PIn/O-MMT nanocomposites were obtained with three different PIn content and coded as: K1 [PIn(94,5%)/O-MMT(5,5%)], K2 [PIn(92,8%)/O-MMT(7,2%)], K3 [PIn(87,9%)/O-MMT(12,1%)]. The samples of PIn, Na-MMT, O-MMT and PIn/O-MMT were characterized by FTIR spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (X-RD), elemental analysis, conductivity, dielectric, magnetic susceptibility, density, particle size measurements, scanning electron microscopy (SEM) and zeta potantial methods. Characterization results showed successfully prepared PIn/O-MMT nanocomposites having intercalation of K2 and K3, and exfoliation of K1 nano-composites structures. A series of volume fractions (5-25%, V/V) were prepared from PIn, K1, K2 and K3 samples in silicone oil (SO) and their sedimentation stabilities determined. The suspensions were subjected to an external electric field strength (E) and electrorheological (ER) activity observed. The effects of dispersed particle volume fraction, shear rate, E, frequency and temperature onto ER activities of these suspensions were investigated, and a non-Newtonian rheological behavior observed. Creep tests were applied to all the suspensions and recoverable viscoelastic deformations determined. Finally, a 65% vibration damping capacity was determined for bentonite/SO suspensions system using an automobile shock absorber under E = 2,5 kV/mm, which may be classified as a smart material; and an important parameter for industrial applications.