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