Preparation Of Functionalized Carbon Nanotube/Continuous Carbon Fiber Multi-scale Reinforced Epoxy Resin Composites And Their Mechanical Properties Investigation

In recent years,carbon fiber/epoxy based composite materials(CFRP)are increasingly applied in numerous fields,including aerospace,lightweight automobiles and ships,wind turbines,and sports equipment,taking advantage of its high specific strength,high specific modulus,low density,corrosion resistance,good fatigue resistance,strong structural dimensional stability,and strong designability.Driven by the new goal of reducing carbon dioxide emissions and the need of lightweight vehicles,the demand for composite materials is expected to continuingly grow.Lately,as the gradually deep study of carbon nanotubes(CNT)as well as other nanomaterials,CNT becomes the research hotspot as a promising reinforcing agent for high-strength polymer composites.In this dissertation,functionalized carbon nanotubes are introduced to enhance continuous carbon fiber epoxy resin-based composites,and multi-scale carbon fiber reinforced epoxy resin composites are prepared through the synergistic effect between nano-fillers of different dimensions to improve the mechanical properties of the composites.The main works are shown as follows:1.The multi-walled carbon nanotubes(MWCNTs)was oxidized,and the surface was carbonylated by treating MWCNTs with mixed acid reflux method.The morphology of MWCNTs was characterized by SEM and TEM.More information was collected from XPS analysis,XRD analysis,Raman analysis and thermogravimetric analysis.2.The MWCNTs/EP(MeTHPA)composites were prepared,and the mechanical properties were studied.The experimental results prove that with the addition of MWCNTs,the cross-section of the MWCNTs/EP(MeTHPA)composite material gradually becomes rough.The mechanical properties of the composite material have been boosted by the addition of MWCNTs.The tensile strength and tensile modulus of MWCNTs/EP(MeTHPA)composite material have been increased by 30%and 14.7%,respectively,and 62.6%of the elongation at break has increased,the flexural strength and flexural modulus increase by 95.4%and 7.24%,respectively.3.The MWCNTs/CF/EP(MeTHPA)composite material was prepared,and the micro morphology and mechanical properties of the composite material were studied.The experimental results show that with the addition of MWCNTs,the fiber and the resin matrix are bonded more tightly,which effectively improves the mechanical properties of the MWCNTs/CF/EP(MeTHPA)composite.The flexural strength and flexural modulus of the MWCNTs/CF/EP(MeTHPA)composite material increase by 10.2%and 6.1%,respectively,and the interlaminar shear strength increases by 8.6%.4.The MWCNTs-AMGNS/CF/EP(MeTHPA)composite was prepared with functionalized MWCNTs and AMGNS as binary fillers.The micro morphology and mechanical properties of the composite material were carefully researched.The final datas show that the binary fillers play a synergistic effect to enhance mechanical properties of the composite material from different dimensions.With the addition of MWCNTs-AMGNS,the flexural strength and flexural modulus of the composite material increase by 14.5%and 9%,respectively,and the interlaminar shear strength increases by 12.9%.