Effects of Epoxy Resin Content on the Mechanical Properties of Carbon Nanotube Films

This study aims to prepare carbon nanotube/epoxy resin composite films with different resin contents and systematically explore the influence of resin content on the mechanical properties and microstructure of composite materials. By preparing carbon nanotube/epoxy resin composite films with different mass fractions of epoxy resin (0%, 5%, 10%, 15%, 20%) and conducting tensile tests using a Gatan micro tester, the influence of epoxy resin content on the tensile mechanical properties of carbon nanotube (CNT) films was revealed. We analyzed the microstructure and fracture morphology of composite films using scanning electron microscopy (SEM). The results showed that at a quasi-static (0.2 mm/min) tensile rate, with the increase in epoxy resin content, the tensile strength of CNT/20wt% EP composite film reached 16.7 MPa, which was 626% higher than that of pure CNT film (2.3 MPa). The fracture strain of pure CNT film is 0.3%, while the fracture strain of CNT/20wt% EP composite material is increased to 0.54%, which is relatively higher than that of pure CNT film. Microscopic characterization revealed that the presence of epoxy resin filled the gaps inside the CNT network, enabling better connection between CNT fibers and thus improving the efficiency of load transfer. This study reveals the influence of epoxy resin content on the properties of CNT films under quasi-static tensile conditions, providing a theoretical basis for the design of high-performance composite materials and providing assistance and reference for the preparation and mechanical research of carbon nanotube/epoxy resin composites in subsequent practical applications.