Preparation And Properties Of Epoxy Resin Matrix Nanocomposites

Epoxy resin?EP?is widely used for its good mechanical properties,strong adhesion,heat resistance,alkali resistance and low cost.However,due to the high cross-linking density of EP,it has some disadvantages such as brittle texture,low flexibility,poor impact resistance and peel resistance.Therefore,in some high-tech applications,the use of EP is limited,so the toughening and modification of EP under the premise of ensuring its excellent performance has become a research hotspot at home and abroad.In this paper,nano particles were used to toughen EP,and the reinforcing effect and mechanism of the composite nanocomposites were described in detail through experiments.The following are the research contents and conclusions:1?Nano TiO₂ doped with metal Fe and Ag was prepared by melting salt method in this paper.The experimental results showed that:transmission electron microscope?TEM?and scanning electron microscope?SEM?could prove that nano TiO₂ doped with Fe and Ag was successfully prepared in this experiment,with uniform size distribution and length between 10 and 25 meters.The results of X-ray diffraction?XRD?show that the crystal type of the sample is rutile.SiO₂ was prepared by sol-gel method.The experimental results showed that SiO₂ was a homogeneous sphere with an average particle size of about 30nm through SEM and TEM.The prepared nano SiO₂ was characterized by Fourier transform infrared?FTIR?and XRD.2?Nano-meter TiO₂,SiO₂,Al₂O₃ and ZnO were filled into EP by ultrasonic mixing method to form EP based nanocomposite.FTIR and XRD were used to analyze the synthesized nanocomposites.The experimental results showed that only the characteristic peaks of EP appeared in the FTIR and XRD patterns of the nanocomposites.3?The tensile and compression tests of EP based nanocomposites were carried out by the electronic experiment universal mechanics testing machine.The tensile test results showed that:when the filling mass fraction of nano TiO₂,SiO₂,Al₂O₃ and ZnO was 10%,the maximum stress that the composites could bear was 117%,105%,132%and 147%higher than EP,respectively.The compression performance test showed that when nano TiO₂ was added to EP as an example,when the content of nano TiO₂ was 10%and the deformation rate was 3mm/min,the compressive elastic modulus and compressive strength of the composite reached the maximum,which were improved by 97.5%and 69.3%respectively compared with EP.Similarly,when nano-SiO₂,Al₂O₃ and ZnO are added into EP,the compressive elastic modulus and compressive strength of the composite materials reach the maximum when the content is 10%and the deformation rate is 3mm/min.4?Thermogravimetric analysis?TG?was used to study the thermal decomposition temperature of composite materials.It was found that the thermal decomposition temperature of EP was 300?,while the thermal decomposition temperature of composite materials with nano TiO₂,SiO₂,Al₂O₃ and ZnO added reached 350?.Through dynamic thermechanics analysis?DMA?analysis,it was found that when adding nano-SiO₂ to EP as an example,at the same vibration frequency,the energy storage modulus of EP was lower than that of the composite materials with nano-SiO₂ filling mass fraction of 5%and10%,but higher than that of the composite materials with nano-SiO₂ filling mass fraction of 15%.At the same vibration frequency,with the increase of nano-SiO₂ content,the glass transition temperature?Tg?of the material showed a nonlinear increase.For example,at the vibration frequency of 10Hz,the Tg of EP,EP/SiO₂-5%,EP/SiO₂-10%and EP/SiO₂-15%were 62.3?,75.8?,74.1?and 77.1?,respectively.Similar rules were observed at other frequencies.At the same content of nano SiO₂,the energy storage modulus,loss modulus and Tg of all materials increase with the increase of vibration frequency.Similarly,when nano TiO₂,Al₂O₃ and ZnO are added into EP,there is a similar rule with the above situation.