Research On The Structure And Performance Of Epoxy Resin/clay Nanocomposite

In recent years,polymer-based nanocomposites,which have attracted attention from both domestic and international academia and industry,have become a new way to improve the performance of general-purpose polymers.The performance of polymer-based nanocomposites depends not only on the dispersion state of the nanofillers in the polymer matrix,but also on the interfacial force between the two phases of the nanocomposites.However,the research of the past20 years mainly focused on how to achieve uniform dispersion and exfoliation of nanofillers in polymer matrix.The research on the interface between polymer matrix and nanofiller and its influence on material properties is still in its infancy.In addition,research reports on the effects of adding nanoclay to polymers on mechanical properties have many controversial results.For this reason,in this paper,epoxy resin was used as the matrix,and different degrees of protonated DMP-30 were selected as organic modifiers to construct different interface strengths.The effect of different interfacial forces on the properties of epoxy resin/clay nanocomposites was studied..At the same time,the effects of clay on the mechanical properties of polymer nanocomposites under different polymer matrix moduli were investigated.The main findings are as follows:1?Partially protonated 2,4,6-tris(dimethylaminomethyl)phenol(PPDMP30)and fully protonated 2,4,6-tris(dimethylaminomethyl)phenol(CPDMP30)were used as Organic modifiers were used to modify the original clay,and two rubbery epoxy/clay nanocomposites with different interfacial strengths were synthesized by"clay slurry composite method"to study the interfacial action on rubbery epoxy/clay nanoparticles.The effect of composite properties.The results show that two different degrees of protonated DMP30 modified clay can obtain a highly random peel structure.The interfacial strength has a significant effect on the mechanical properties of the nanocomposites:PPDMP30 modified clays can retain a strong interfacial force between the epoxy resin matrix and the clay flakes by retaining the tertiary amine groups that can participate in the curing reaction.When the clay mass fraction is 2%,the tensile strength of the epoxy/clay nanocomposite can be increased by nearly 300%;while the fully protonated DMP30 modified clay can only make the nanocomposite due to the relatively weak interface strength.The strength is increased by 90%.The addition of two organic clays(whether the interface is strong or weak)has no significant effect on the T_g of the material.2?Choose three kinds of clay with different aspect ratio(southern-clay,length to diameter ratio300-500;PGW-clay,length to diameter ratio 200-400;PGV-clay,length to diameter ratio 140-200),select partial protonated as an organic modifier 2,4,6-tris(dimethylaminomethyl)phenol(DMP-30)was synthesized into three kinds of organic clays(S-clay,W-clay,V-clay).The corresponding epoxy/clay nanocomposites were prepared by"clay slurry composite method"to investigate the effect of clay aspect ratio on the properties of epoxy/clay nanocomposites.The results show that V-clay exists in the intercalation structure in the epoxy resin,while S-clay and W-clay are dispersed in the epoxy resin in a random exfoliation structure.As the content of organoclay increases,the T_g of the three epoxy resin nanocomposites increases.When the mass fraction of organoclay was 3%,the T_g of the three epoxy resin nanocomposites(S-clay,W-clay and V-clay)increased by 4.3?,4.5?,and 4.6?,respectively.With the increase of organoclay content,the mechanical properties of epoxy/S-clay nanocomposites decreased gradually.The mechanical properties of epoxy nanocomposites with V-clay and W-clay added slowly.When the mass fraction of organoclay is3.5%,the tensile strength of epoxy/S-clay nanocomposites is reduced by 16.9%;and the tensile strength of epoxy/V-clay and epoxy/W-clay nanocomposites are respectively Increase by 5.4%,4.8%.3?Two kinds of organicized clays(S-clay,V-clay)were synthesized by using partially protonated DMP-30 as organic modifier.A series of epoxy resins with different matrix moduli were prepared by changing the ratio of E51/PPGDGE./Clay nanocomposites.The effects of clay on the mechanical properties of polymer/clay nanocomposites under different matrix moduli were systematically investigated.The results show that the reinforcing effect of the organicized clay on the epoxy resin decreases with the increase of the modulus of the epoxy resin.When the modulus of the epoxy resin increases to a certain value,the addition of clay will degrade the mechanical properties of the epoxy resin..When the mixed epoxy resin modulus is 1.89 MPa,516 MPa,1789MPa and 2103 MPa,the S-clay with a mass fraction of 2%increases the tensile strength of the epoxy resin nanocomposites by 198.2%,66.3%,and 6.09%,respectively.-63.9%;the same mass fraction of V-clay increases the tensile strength of epoxy resin nanocomposites by 74.8%,28.3%,11.5%,and-2.1%,respectively.In different epoxy resin matrix,S-clay and V-clay have different reinforcing effects on epoxy resin.When the modulus of epoxy resin is low(less than 1200MPa),S-clay is epoxy resin.The reinforcing effect is better than V-clay;when the modulus of epoxy resin is higher(greater than 1200 MPa),the situation is completely opposite,and the reinforcing effect of V-clay on epoxy resin is better than that of S-clay.