Application of nanomaterials in epoxy resins

China Coatings Online News Information: Nanomaterials are materials with an average particle size below l00nm. The average particle size of 20 to 100 nm is called ultra-fine powder, and the average particle size is less than 20 nm is called ultra-micro-powder. Nanomaterials have a considerable phase interface area, it has many macro-objects do not have the new physical and chemical characteristics, is not only a multi-part substance dispersion system, but also a new type of material. The research of nanomaterials started from metal powder, ceramics and other fields, and has been widely used in microelectronics, metallurgy, chemical industry, electronics, national defense, nuclear technology, aerospace, medicine and bioengineering. In recent years, the research of dispersing nanomaterials in polymers to improve the properties of polymer materials has become more and more active, and many considerable achievements have been made.
1, the characteristics of nanomaterials
Because the nanomaterial grain is very small, the surface area is very large, the atomic fraction arranged in disorder on the surface of the grain is much larger than the proportion of atoms on the surface of the crystalline material, resulting in nanomaterials have many special basic properties that traditional solids do not have, such as Volume effect, surface effect, quantum size effect, macro quantum tunnel effect and dielectric limit domain effect, so that nanomaterials have microwave absorption performance, high surf activity, strong oxidation, super-flugic and absorption spectrum performance of blue or red shift phenomenon. In addition to the basic characteristics mentioned above, nanomaterials also have special optical properties, catalytic properties, photocatalytic properties, photochemical properties, chemical reaction properties, chemical reaction dynamics and special physical and mechanical properties.
2, nanomaterial types
(1) nano-silicon dioxide
nomes silica reunion body is a non-stereotyped white powder, the surface molecular state is a three-dimensional mesh structure. This structure gives the coating excellent tentacle performance and dispersion stability. Nano-silicon dioxide has strong UV absorption and infrared reflection properties, which can improve the anti-aging properties of coatings. The treatment of the surface of nano-silica can make the surface of silica nanoparticles have both hydro-hydro-based and oil-based groups, and the affinity of nanomaterials greatly expands its application. For different types of coatings, the addition of nano-silicon dioxide is generally 0.1%-1.0%, up to a maximum of 5%.
(2) nano-titanium dioxide
-nano-titanium dioxide is one of the main nanomaterials developed in the late 1980s. The optical effect of nano-titanium dioxide varies with particle size, especially nano-gold-redstone titanium dioxide, which has a color-changing effect with angle. The particle size of nano-titanium dioxide is generally 10 to 50 nm, and the addition is controlled at less than 1.0%.
(3) nano-zinc oxide
-nan zinc oxide has a general zinc oxide can not be compared with the new properties and new uses, with shielding ultraviolet rays, absorption of infrared and anti-mold action. Nano-zinc oxide also has a thickening effect, which helps the stability of pigment dispersion.
(4) other nanomaterials
commonly used in other nanomaterials are ultra-fine carbon black, gas phase silica, nano-scale calcium carbonate, etc. , all belong to the nano-material category. However, the dispersion of carbon black, the addition of gas-phase silica and the rational use of calcium carbonate still need further study.3, nanomaterials in epoxy resin applications
nanomaterials in epoxy resin applications are mainly in composite materials and coatings.
in existing composite materials, fiber is usually used as a reinforcing material, which limits the performance of composite materials due to the compatible problems between fibers and substations. In order to solve the compatible problem and give full play to the excellent performance of composite materials, people design composite materials from the molecular level. By controlling the dispersion and compounding of nanomaterials in polymers, it can strengthen, fill and increase the interface force in the micro-regions where the resin is weak, and reduce the action of free volume, which may effectively change the comprehensive properties of composite materials in a considerable range without affecting the processing performance of the materials.
Zhang L D et al. research shows that a-Al2O3 is composited with epoxy resin to increase its mod, and when the particle size is 27nm and a-Al2O3 addition is 1% to 5% (mass ratio), the Tg of epoxy resin is increased, and the mod is increased by more than 10% (mass ratio).
Wang Lixin and others used hexamine to modifie the reaction of clay through ion exchange, and then mixed the modified clay with E-51 in dmi methamphetamine (DMF) to prepare epoxy resin/clay nanocomposing materials. When the nano-clay addition is 3wt%, Martin has heat resistance of 61.5 degrees C and impact toughness of 8.95kj/m2, which is only 20 degrees C and 190% higher than the solidified resin without clay, respectively.
, Muks Wang et al. used powder to polymerized low-molecular epoxy resins into ethers between clay layers. In this study, E-51 was mixed with treated clay to produce a polyether powder at high temperature, which was polymerized with a layered reaction of clay.
Usuki-A et al. described the clay-modified epoxy resin using solvent method, in solvent N, N'-methyl methamide, E-51 under its action interspersed between the clay crystal layer, and then add curing agent curing, so that the two compound good, performance has been greatly improved. In addition, the in-place composite method of insertion is used to prepare epoxy/clay nanocomposing material by embedding the monosome into the clay mezzanine and re-curing.
4, China's nanomaterials research and production overview
According to expert analysis, China's comprehensive research level of nanomaterials in the advanced ranks, but as far as the application of nanomaterials, China is still in its infancy.
since the mid-1980s, nanoscience and nanotechnology have received more and more attention from the Chinese government. At the symposium on the development strategy of nanotechnology held in November 1991, it was agreed that nanotechnology is a rising strategic field of science and technology, and nanotechnology is in a period of major breakthrough. At the meeting, the development strategy of nanotechnology was formulated, and the development of nanotechnology in China was deployed, among which the preparation science and performance research of nanomaterials was listed as the key project of the Eighth Five-Year Plan. The 10-year Nanoscience Climbing Program (1990-1999) and a series of advanced materials research programs are core activities.
According to the Life Times, China has built nine nanotechnology research bases, the Institute of Solid Physics of the Chinese Academy of Sciences, Nanjing University, Shanghai Silicate Research Institute, Tsinghua University, Peking University and other units have formed a team engaged in nanotechnology research, and achieved a series of encouraging results in the international community, some even in the forefront of the world. China has the strength of research areas are nano-carbon needles and the use of nanotube production process development. The Chinese Physical Society and the Chinese Particle Society are committed to the spread of nanotechnology. China's nanotechnology has made a breakthrough. At present, China has a number of enterprises engaged in the production and development of nanomaterials, and a number of products on the market, and achieved good economic and social benefits. Nanomaterials have been used in some sports venues in Beijing, with remarkable results, contributing to China's bid for the 2008 Olympic Games.
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