Effect of sodium dodecyl sulfate on thermal properties of polyvinyl alcohol (PVA)/modified single-walled carbon nanotube (SWCNT) nanocomposites

This work was first started by modifying the single-walled carbon nanotube (SWCNT) with hydroxylation and silane reactions. Then, poly(vinyl alcohol) (PVA)/p-SWCNT, PVA/modified p-SWCNT, PVA/SDS/p-SWCNT and PVA/SDS/modified p-SWCNT nanocomposites were produced using the solution casting method. The effects of filling ratio, surfactant and functional group types on thermal properties of these nanocomposites were investigated by differential thermal analysis/thermogravimetry and differential scanning calorimetry. Structural and morphological properties of the samples were also examined using Brunauer-Emmett-Teller device, Fourier transform infrared-Attenuated total reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy and atomic force microscopy. It has been determined that the surface area of p-SWCNT decreases with the modification. Thermogravimetric analysis showed that the thermal stability of the composite depends on the loading fraction, the type of functional group and especially SDS. PVA and its nanocomposites degraded in two steps. The addition of SDS to PVA matrix increased thermal stabilities and glass transition temperatures of nanocomposites. PVA/SDS/p-SWCNT-OH nanocomposite was found to have the highest Tg temperature.