Preparation and thermal properties of multiwalled carbon nanotube/polybenzoxazine nanocomposites

Abstract

In this study, we prepared nanocomposites comprising multiwalled carbon nanotubes (MWCNTs) and polybenzoxazine (PBZ). The MWCNTs were purified through microwave digestion to remove most of the amorphous carbon and metal impurities. After purification, MWCNTs were treated with H 2 SO 4 /HNO 3 (3 : 1) to introduce hydroxyl and carboxyl groups onto their surfaces. Raman spectroscopy revealed the percentage of nanotube content improved after prolonged microwave treatment, as evidenced by the decrease in the ratio of the D (1328 cm ) bands. For the untreated MWCNTs, the I D /I G ratio was 0.56. After microwave treatment for 40 min, the value decreased to 0.29, indicating that the percentage of nanotube content improved. Dynamic mechanical analyses (DMAs) revealed that the storage moduli and the T g s of the MWCNTs/PBZ nanocomposites were higher than that of the pristine PBZ. This is due to the nanometer-scale MWCNTs restricting the motion of the macromolecular chains in the nanocomposites. Transmission electron microscopy (TEM) image revealed that the MWCNTs were well dispersed within the PBZ matrix on the nanoscale when the MWCNT content was less than 2.0 phr. The coefficient of thermal expansion (CTE) of the nanocomposites decreased on increasing the MWCNTs content.

In situ preparation of high performance polyimide nanocomposites based on functionalized multiwalled carbon nanotubes

“…The X-ray patterns of the MWNT displayed the presence of two peaks at 2h = 25.8 o and 42.7 o corresponding to the (002) and (100) reflections of the carbon atoms, respectively, which is in good agreement with the literature values [40]. Pure PI showed broad diffraction peaks at 2h = [18][19][20][21][22][23] o . The X-ray pattern of the NC5% showed mixed peaks appearing in the MWNT and pure PI, respectively.…”

“…These reactive groups on CNTs will greatly enhance the combination of CNTs with polymeric matrix, thus improving the mechanical strength of the NCs [19]. Sidewall functionalization of CNTs also improves the dispersion of CNTs in a polymeric matrix [20][21][22][23][24].…”

Benzoxazine resin and their nanostructured composites cure kinetic by DSC

“…2 Both forms of CNTs exhibit remarkable strength and rigidity conductivity due to the nature of the graphite structure of the nanotube. [24][25][26][27][28][29][30] Theoretical and experimental results suggest that the elastic modulus of CNTs may exceed 1.0 TPA and the tensile strength is in the range of 10-50 GPa. Studies on CNTs as reinforcement of polymeric materials have gained wide acceptance because of their outstanding properties and diverse field of application.…”

“…The ends of the nanotubes may or may not be closed by fullerene semi structures. [24][25][26][27][28][29][30] Based on the number of carbon layers through the wall, we can classify CNTs as single-walled (SWNT), where a single sheet of graphite rolled up on itself forms a tube cylindrical, or multiwalled carbon nanotubes (MWCNTs) consisting of graphite-rolled sheet, forming multiple concentric cylinders spaced from each other from 0.34 to 0.36 nm. 2 Both forms of CNTs exhibit remarkable strength and rigidity conductivity due to the nature of the graphite structure of the nanotube.…”

Mechanical properties and degradation studies of poly(D,L‐lactide‐co‐glycolide) 50:50/graphene oxide nanocomposite films

“…[1][2][3][4] The incorporation of nanofillers such as carbon nanotubes and silica particles into polymer matrix has satisfactorily enhanced both the mechanical and thermal properties of the resultant nanocomposites. [5,6] In recent years, there has been great interest in using graphene-based nanofillers because there are no previous materials that have displayed the combination of superior mechanical, thermal, and electronic properties attributed to graphene. [7][8][9][10] These properties make graphene an ideal material for a wide range of applications.…”