Carboxyl graphene reinforced melamine-based polyamide nanocomposites

Abstract

Over the years, various types of techniques have been used for the synthesis of nanocomposites. In this work, melamine-based polyamide (PA) was synthesized using a one-pot polycondensation method under mild conditions. carboxyl graphene (CG)/PA nanocomposites (CGMPA) were prepared by CG nanofiller loadings of 1, 3, and 5 wt.% via delamination/adsorption approach. The prepared CGMPA nanocomposites were characterized using different analyses, such as Fourier transform infrared techniques (FTIR), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), differential scanning calorimetric (DSC), and thermogravimetric analysis (TGA). The effects of the CG on the thermal properties of the CGMPA nanocomposites were significant. The results showed that the melting temperature (Tm) of neat PA and CGMPA were increased from 378°C to 393°C suggested better dispersion of CG in PA matrix. The decomposition temperature of PA was increased from 451°C to 463°C in CGMPA nanocomposites indicates the better thermal stability of PA matrix by addition of CG.

Carboxyl-functionalized graphene reinforced aromatic polyamide nanocomposites

“…It was seen that CG showed wrinkled sheet type morphology with dark and bright areas. 33 CGPA nanocomposites show overlapped patterns of CG stacked sheets in PA. The CGPA1 and CGPA3 nanocomposite showed well distributed and exfoliated morphology, and CG sheets were dispersed in PA with no aggregation.…”

“…The CGPA1 and CGPA3 nanocomposite showed well distributed and exfoliated morphology, and CG sheets were dispersed in PA with no aggregation. However, the CG was less distributed in CGPA5 nanocomposites with large aggregation in PA. 33,40 The good dispersion of CG nanoparticles in the PA is one of the main characteristics to boost the physical properties of the PA because the aggregation of the CG will lead to structural defects of the nanocomposites. 33,41

Figure 5.FESEM images of carboxyl graphene(CG) and CGPA nanocomposites CG (a), CGPA1 (b), CGPA3 (c) and CGPA5 (d).

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“…The CGPA1 and CGPA3 nanocomposite showed well distributed and exfoliated morphology, and CG sheets were dispersed in PA with no aggregation. However, the CG was less distributed in CGPA5 nanocomposites with large aggregation in PA. 33,40 The good dispersion of CG nanoparticles in the PA is one of the main characteristics to boost the physical properties of the PA because the aggregation of the CG will lead to structural defects of the nanocomposites. 33,41 The XRD patterns of CG, PA and CGPA-x are shown in Figure 6.…”

“…According to our previously reported study, 33 the delamination/adsorption method was applied for synthesis of CGPA nanocomposites. 34,35 Calculation for CGPA with 1 wt.% of CG, 10 mg of CG was immersed in DMAc and sonicated to form delaminated suspension for 30 min.…”

“…In this study, the effect of AD-carboxyl graphene (CG) nanofiller on the properties of PA has been investigated. The delamination/adsorption method 33,34 is used to prepare novel CG-reinforced PA nanocomposites (CGPA) which are obtained by intercalation of delaminated dispersion of CG in the PA matrix. The nanocomposites were characterized through structural, morphological and thermal analysis to determine the influence of the CG nanofiller on the thermal properties of the nanocomposites.…”