Study On Preparations And Relevant Mechanism Of Mechanical/Thermal Properties Of MWCNTs/EP Nanocomposites

For the excellent properties performe, epoxy resin was widely used inaviation, construction, machinery, electronics and other fields. However, it ishindered its further applications, due to the cured epoxy resin caused by highdensity and the brittleness of the shortcomings of poor impact resistance.Furthermore, the brittleness of cured epoxy resin, to a certain extent, limit itsapplication in certain high-tech fields, therefore the toughening modification ofepoxy resin has become a hot topic at home and abroad. The unique one-dimensional hollow tubes structure provides carbon nanotubes higher elasticity,strength and modulus, which is considered one of the most promisingreinforcement materials in the21st Century. In recent years, people have done alot of work on toughened epoxy resin and improve its heat resistance, however, atthe aspects of carbon nanotube aspect ratio and the functional mode on theperformance of epoxy resin have seldom been reported.In this paper, the epoxy resin was enhanced by two kinds of carbonnanotubes with different draw ratio (MWCNTs1020and MWCNTs4060), the carbonnanotubes was modified by carboxyl functional and epoxy functional. TheC-MWCNTs1020/EP and C-MWCNTs4060/EP and E-MWCNTs4060/EP three epoxyresin nanocomposites were prepared by mixing solution method. The dispersionof before and after the functionalized MWCNTs in acetone were characterized byscanning electron microscopy (SEM). The impact strength of composites wastested by simply supported beam impact apparatus, and the nanometer materialtoughening mechanism of resin matrix was analyzed. The bending strength andbending modulus of composites were tested. At the same time, the effect of nanomaterials on the thermal performance was researched. The results show that: the epoxy-functionalized carbon nanotubes dispersedbetter in solvent than carboxyl functionalized carbon nanotubes; In this study nomatter with any draw ratio of the carbon nanotubes, the doping amount canimprove the mechanical properties and thermalproperties of epoxy resin in acertain extent. When the carbon nanotubes content is in the range of0-0.6wt%,small diameter carbon nanotubes is more effective to the improvement ofmechanical properties of specimen, when the C-MWCNTs1020concentration is0.6wt%and the impact strength increase by54.9%than the undoped EP. Andwhen the amount of carbon nanotubes doped is during0.6wt%-1.0wt%, largediameter is more advantageous to the improvement of mechanical properties.When the C-MWCNTs4060concentration is0.8wt%the sample’s impact strengthincreased by60.8%than the undoped EP. The functionalization carbon nanotubeshave great influence on the performance of epoxy resin, with the same amount ofcarbon nanotubes doped the mechanical and thermal properties ofE-MWCNTs4060/EP are better than C-MWCNTs4060/EP.