Next Article in Journal
Crystallization and Quantification of Crystalline and Non-Crystalline Phases in Kaolin-Based Cordierites
Previous Article in Journal
Effect of Zn Content on the Microstructure and Mechanical Properties of Mg–Al–Sn–Mn Alloys
Open AccessArticle

Effects of Non-Covalent Functionalized Graphene Oxide with Hyperbranched Polyesters on Mechanical Properties and Mechanism of Epoxy Composites

1
Institute of Field Engineering, Army Engineering University of PLA, Nanjing 210007, China
2
National Defense Engineering Institute, Army Engineering University of PLA, Nanjing 210007, China
*
Author to whom correspondence should be addressed.
Materials 2019, 12(19), 3103; https://doi.org/10.3390/ma12193103
Received: 7 September 2019 / Revised: 18 September 2019 / Accepted: 20 September 2019 / Published: 23 September 2019
In order to improve the interfacial properties of graphene oxide (GO) and epoxy resin (EP), hyperbranched polyesters with terminal carboxyl (HBP) non-covalently functionalized graphene oxide (HBP-GO) was achieved by strong π-π coupling between hyperbranched polyesters and GO nanosheets. The effects of non-covalent functionalization of GO on the dispersibility, wettability and interfacial properties were analyzed. The mechanical properties and enhancement mechanism of HBP-GO/EP composites were investigated. The results show that the hyperbranched polyesters is embedded in the GO layer due to its highly branched structure, which forms the steric hindrance effect between the GO nanosheets, effectively prevents the agglomeration of GO nanosheets, and significantly improved the dispersibility of GO. Simultaneously, the contact angle of HBP-GO with EP is reduced, the surface energy, interfacial energy and adhesion work are increased, then the wetting property of HBP-GO is significantly improved. The main toughening mechanism of HBP-GO is microcrack deflection induced by HBP-GO and plastic deformation of the EP matrix. In the microcrack propagation zones, HBP-GO may produce the pinning effect near the microcrack tips and change their stress state, resulting in microcrack deflection and bifurcation. So, the microcrack propagation path is more tortuous, which will consume much more fracture energy. Therefore, the mechanical properties of the HBP-GO/EP composites are greatly improved. View Full-Text
Keywords: epoxy composites; graphene oxide; hyperbranched polyesters; mechanical properties; non-covalent functionalization epoxy composites; graphene oxide; hyperbranched polyesters; mechanical properties; non-covalent functionalization
Show Figures

Figure 1

MDPI and ACS Style

Tian, J.; Xu, T.; Tan, Y.; Zhang, Z.; Tang, B.; Sun, Z. Effects of Non-Covalent Functionalized Graphene Oxide with Hyperbranched Polyesters on Mechanical Properties and Mechanism of Epoxy Composites. Materials 2019, 12, 3103.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop