Thermal and mechanical properties of carbon nanotube/epoxy nanocomposites reinforced with pristine and functionalized multiwalled carbon nanotubes

Abstract

In this study, the effects of functionalization and weight fraction of mutliwalled carbon nanotubes (CNTs) were investigated on mechanical and thermomechanical properties of CNT/Epoxy composite. Epoxy resin was used as matrix material with pristine-, COOH-, and NH 2 -functionalized CNTs as reinforcements in weight fractions of 0.1, 0.5, and 1.0%. Varying (increasing) the weight fraction and changing type (pristine or functionalized) of CNTs caused increment in Young's modulus and tensile strength as observed during mechanical tests. CNT reinforcement improved thermal stability of the nanocomposites as observed by thermogravimetric analysis. Thermomechanical analysis showed a slight reduction in free volume of the polymer, that is a drop in coefficient of thermal expansion, prior to glass transition temperature (T g ) beside a slight increase in T g value. Dynamic mechani-cal analysis indicated an increase in storage modulus and T g owing to the strength addition of CNT to the matrix alongside the hardener. Scanning electron microscopy analysis of the fractured surface(s) revealed that CNTs were well dispersed with no agglomeration and resulted in reinforcing the matrix. POLYMER COMPOSITES-2015 FIG. 4. Dimensional change as a function of temperature for pure epoxy and different epoxy/CNT composites. FIG. 5. DMA studies of neat epoxy and different CNT/E composites for a range of temperatures at 1.0 Hz frequency and 5 C/min heating rate: (a) storage modulus and (b) dissipation factor (tan d).FIG. 3. TGA weight loss data over a range of temperatures for neat epoxy and nanocomposite samples.

Synergetic effects on the mechanical and fracture properties of epoxy composites with multiscale reinforcements: Carbon nanotubes and short carbon fibers

“…On the other hand, the internal stress in the cured composites could be divided into two parts, that is, the volume‐shrinkage‐caused internal stress and the difference in the coefficient of thermal expansion caused by internal stress . The addition of MWNTs decreased the volume shrinkage, and the coefficient of thermal expansion of the epoxy matrix contributed to a reduction in the internal stress level of the cured composites according to Jyotishkumar et al …”

Effect of graphene and CNT reinforcement on mechanical and thermomechanical behavior of epoxy—A comparative study

“…Figure (a,b) are typical tan δ (loss factor) versus temperature plots, the peak value of which suggest the glass transition temperatures ( T g ) . The increase or decrease in T g and tan δ peak is completely influenced by the interaction between the Gr/CNT and polymer, as it dictates the segmental mobility of polymer chain.…”

Graphene Polymer Nanocomposites for Fuel Cells

“…Reproduced with permission from John Wiley & Sons PVA [41]. The disadvantage of solution mixing is creation of voids by the solvent during evaporation process that introduces the structural defects which brings poor thermal and electrical conductivity [42]. Besides simple mixing method, melt blending has also been developed, and considered more feasible for the simple reason of being free of solvents.…”