Facile preparation of polyamide 6/exfoliated graphite nanoplate composites via ultrasound‐assisted processing

Abstract

In this work, we report a facile strategy to prepare polyamide 6/exfoliated graphite nanoplate (PA6/xGNP) nanocomposites by in situ exfoliation of expanded graphite (EG) via ultrasound‐assisted extrusion. The EG was preliminarily exfoliated by ultrasonication, and then blended with PA6 and further exfoliated into graphite nanoplates during the ultrasound‐assisted extrusion process. Compared with chemical exfoliation of EG, ultrasonic exfoliation minimized defects in the carbon layers. Meanwhile, the in situ exfoliation of EG via ultrasound‐assisted extrusion prevented the reagglomeration of xGNPs in the melt blending process. The well‐dispersed xGNP structure significantly improved the mechanical performance of PA6 composites; with an xGNP loading of only 0.5 wt%, the tensile and flexural strengths of the PA6 nanocomposite increased from 65.4 and 67.8 MPa to 90.5 and 91.2 MPa, respectively. The heat deflection temperature also greatly improved from 76.5°C to 115.4°C by adding 1 wt% xGNPs. These results demonstrate a promising approach for large‐scale fabrication of high‐performance polymer/xGNP nanocomposites. POLYM. ENG. SCI., 58:1739–1745, 2018. © 2017 Society of Plastics Engineers

SMA-Assisted Exfoliation of Graphite by Microfluidization for Efficient and Large-Scale Production of High-Quality Graphene

“…This is consistent with the results published in the literature [35]. Compared to other graphenereinforced polyamide composites [32,36,37], as shown in Table 1, greater improvements in mechanical properties are observed for the EG/PA66 composites investigated in this study. It is well-known that the mechanical properties of composites are enhanced by good dispersibility and strong interfacial adhesion between the modifier and the matrix.…”

“…This indicates that the samples possess analogous lamellae thicknesses and spherulite sizes [37]. Moreover, the EG/PA66 composites exhibit higher crystallization temperatures (Tc) compared to pure PA66, which signifies that EG acts as an effective heterogeneous nucleating agent that promotes crystallization [33,37]. The greatest crystallinity (Xc = 36.6%) is achieved using 0.3 wt% EG, leading to the highest tensile strength of the composites.…”

“…The DSC curves and data presented in Figure 13 and Table 2, respectively, show that the melting temperatures (Tm) of the investigated composites are practically the same, irrespective of the EG content. This indicates that the samples possess analogous lamellae thicknesses and spherulite sizes [37]. Moreover, the EG/PA66 composites exhibit higher crystallization temperatures (Tc) compared to pure PA66, which signifies that EG acts as an effective heterogeneous nucleating agent that promotes crystallization [33,37].…”

Nanocomposite and biodegradable polymers applied to technical textiles

“…Ultrasonic exfoliation minimizes defects in carbon layers compared to chemical methods. Exfoliation prevented the reaglomeration of particles in the process of mixing in the molten state, and the dispersed structure significantly improved the mechanical and thermal performance of the compounds [45].…”

Highly Enhancing Electrical, Thermal, and Mechanical Properties of Polypropylene/Graphite Intercalation Compound Composites by In Situ Expansion during Melt Mixing

“…Ultrasound-assisted processing was also used to improve the dispersion of EG in the polymer matrix during melt extrusion. Yang et al [ 21 ] prepared polyamide 6/EG composites via preliminarily exfoliating EG and melt extrusion with ultrasound-assisted mixing. The dispersion of EG in the composites was clearly improved, which led to significantly enhanced mechanical property of the composites.…”