Carbon nanotubes and polyaniline filled hybrid epoxy composites: Assessing the viscoelastic behavior and mechanical properties

In the current work, polyaniline (PANI) and epoxy (EP) composites were prepared and the effect of carbon nanotubes (CNT) addition to EP/PANI (5%) composite on mechanical and viscoelastic properties was studied. PANI was synthesized using p ‐toluenesulfonic acid (PTSA) as dopant and characterized through UV–vis and FTIR spectroscopy. Viscosity of uncured EP and composites was studied as a function of shear rate and found to increase with fillers concentration. Dynamic mechanical analysis revealed that PANI increased the storage modulus wherein glass transition temperature ( T g ) almost remains constant. Addition of 0.1% CNT to EP/PANI (5%) composite further raised the modulus whereas 0.4% CNT had no significant effect on storage modulus due to agglomeration. However, peak intensity of tan  δ curve and T g were improved for both CNT concentrations. Mechanical properties like tensile, flexural, and impact strength remained unaltered at low PANI (5%) content while at high loading these properties deteriorated significantly. 0.1% CNT has marginal effect on mechanical strength of EP/PANI (5%) system while 0.4% CNT notably reduced the properties. Morphological studies showed that PANI had good dispersion in matrix at lower loading (5%) while it forms uniformly distributed aggregates at higher contents. PANI dispersion was not affected by inclusion of CNT. POLYM. COMPOS., 40:E1143–E1150, 2019. © 2018 Society of Plastics Engineers