A promising approach to enhanced thermal stability of DC conductivity of polyaniline - functionalised multi-walled carbon nanotube composites

摘要

Nanocomposites of polyaniline and 4-aminobenzoyl functionalised multiwalled carbon nanotubes (PANI-FMWCNT) were synthesised through interfacial polymerisation of aniline in presence of FMWCNT and protonating with various dopants. The composites were characterised by SEM, TEM and TGA. The high temperature DC conductivity stability was investigated through cyclic accelerated ageing and isothermal ageing studies. On thermal cyclic treatment up to 150℃, after the fifth cycle, electrical conductivity for various acid doped PANI samples rapidly dropped to 42-59% of their initial values, while PANI-FMWCNT samples showed only negligible decrease to 80-87%. Isothermal ageing studies showed that the PANI samples started reduction in conductivity at 110℃ whereas nanocomposites retained conductivity stability even at 140℃. Both neat PANI and composites containing NSA and TSA had a higher thermal stability of electrical properties than polyaniline doped with HCl and H_2SO_4. The role of FMWCNTs in stabilising the DC conductivity of composites at elevated temperature is discussed.