Experimental Study On Nano-modification Of Epoxy Adhesive Based On Active Groups

Epoxy resin has good mechanical properties,adhesive properties,insulation properties and thermal stability.Because of its convenient processing,stable chemical properties,acid and alkali resistance,and low cost,it is widely used in bonding metals,non-metals and thermosetting materials.Such as:the bonding between ultra-high performance concrete(UHPC)and the thin asphalt surface layer,the use of carbon fiber reinforced resin matrix composites(CFRP)to strengthen fatigue-damaged steel structures,etc.Existing epoxy resin reinforcement and toughening research work mainly focuses on the modification of different dosages,particle sizes and single nanomaterials,and less consideration is given to the influence of different active groups on the modification effect and the synergy between various nanomaterials.Conventional tests use manual stirring to disperse nanomaterials in the process of making adhesive specimens,resulting in uneven dispersion of nanomaterials in epoxy resin.At present,simulations based on the mechanical properties of adhesives need to be improved.Based on the existing results of the research group,this paper conducts experimental research on the mechanical properties of nano-material modified epoxy adhesives with different dosages and types,and uses ABAQUS analysis software to carry out tensile performance simulation simulations.The application has a certain contribution.The specific work is as follows:1.The tensile performance,bending performance and fracture toughness test of nano-SiO2 particles and nano-TiO2 particles modified epoxy adhesives are carried out under normal temperature conditions.The results show that the addition of 0.05wt%nano-SiO2 particles and 0.40wt%nano-TiO2 particles has the best effect on improving the mechanical properties of epoxy adhesives.The tensile strength and tensile modulus of the former reached 54.45MPa and 5950MPa,respectively,compared with pure epoxy adhesive,increase 36.12%and 32.22%;2.Amino-modified nano-SiO2 particles(SiO2-NH2)and methacrylic modified nano-SiO2 particles(SiO2-C4H8)modified epoxy adhesives tensile properties,flexural properties,impact properties,and shear at room temperature Performance and bonding test of CFRP/steel double lap joint.The results show that the modification effect of SiO2-NH2,SiO2-C4H8 and inactive group-modified nano-SiO2 particles(SiO2-0)on epoxy adhesive:SiO2-C4H8>SiO2-NH2>SiO2-0;3.Using scanning electron microscope(SEM)to analyze the morphology of the colloidal tensile cross-section,revealing the strengthening and toughening mechanism of the active group nano SiO2 on the epoxy resin from the micro level.On this basis,the mechanical properties of carboxyl modified multi-walled carbon nanotubes(MWCNTs-COOH)synergistically with SiO2-NH2 and SiO2-C4H8 modified epoxy adhesives were studied.The results showed that under the synergistic effect of MWCNTs-COOH,SiO2-NH2 and SiO2-C4H8 have further improved the mechanical properties of epoxy adhesives;4.Based on the test results,the script is written in Python language,and the two-dimensional RVE model is generated in ABAQUS to simulate the tensile performance of the adhesive.Compared with the test results,the model has a certain degree of reliability.On this basis,a predictive evaluation of the undeveloped test plan is carried out to provide a reference for the test.