In 2011, the research progress of adhesive
Reproduced the Internet
introduction
Adhesive is a kind of old and young materials. As early as in thousands of years ago, the ancestors of human beings will have begun to use adhesive. According to research [1], the museum of conscientiousness unearthed large coloured drawing or pattern of qin TongCheMa manufacturing, is already used phosphate inorganic adhesive. Analysis of a joint silver TongCheMa unearthed the white block, and found that it used the composition and modern adhesive phosphate adhesive basic same. The northern wei dynasty jia sixie wrote, that the yaoshu ink in chapter ninety-one of the system is introduced in the process of use the ink and adhesives. To at the beginning of the last century, the invention of the synthesis of phenolic resin, open the modern history of the adhesive. At present, and the three synthetic polymer materials production comparison, adhesive accounts for only of the fifth, but years of growth speed, ranks first. China adhesives started in the 1950's, in the 90 s, adhesive industry has been developing by leaps and bounds. Now, adhesive seeped to industry, agriculture, transportation, medical, defense and People's Daily life in all areas of the national economy in play more and more major role, adhesive industry has been developed as a separate emerging department. It is estimated that by 2005, China's synthesis of the adhesive consumption will reach 2.65 million t, with an average annual growth rate of over 8%.
1, the kinds of adhesive
According to not complete count, so far more than 6000 kinds of adhesive products come out, because its variety and different components, at present there is no unified classification method. According to the different way of curing can be divided into molten ical cured adhesive, volatile ical cured, under water, reaction ical cured ical cured.
1.1, melting ical cured
Molten ical cured adhesive is refers to the adhesive in molten state heated under a kind of adhesive bonding. One of the more common application for soldering, silver solder and so low melting point metal, stick, granular, membrane EVA (polyethylene acetate ethylene) hot melt adhesive.
1.2, volatile ical cured
Volatile ical cured adhesive refers to water in the adhesive or other solvents in the air in the volatile nature, thus forming a kind of cured adhesive adhesives. Like water glass series adhesives, neoprene, etc.
1.3, ical cured in water
Ical cured adhesive in water is to point to in water happens namely after chemical reaction and curing of condensation material. Among them with plaster, all kinds of cement as a representative.
1.4, reaction ical cured
Ical cured adhesive reaction is to point to by sticky materials and water outside of the material produce chemical reaction form of a class of curing adhesive adhesives. Phosphate kind of adhesive, dental daub, alpha QingJiBingXiSuanZhi instant dry glue, acrylic double ester anaerobic glue belong to this category.
2, the characteristics of the adhesive
2.1, resistant temperature resistant temperature is one of the excellent characteristics of inorganic adhesive. Inorganic high temperature adhesive in the 1500 range are often used to 1750 ¡æ, the temperature and phosphoric acid copper oxide adhesive wider, can be in 180 ~ 1400 ¡æ scope to use. But the main use inorganic high temperature adhesive is aggregate zirconium English sand and refractory soil, zirconium English sand prices higher, mainly rely on imports, refractory soil at the expense of the land to to get huge cost. So, looking for cheap are easy to replace traditional products aggregate to reduce production cost is a priority. Some organic adhesive through the modification has also reached the high temperature resistant performance. For example, using B4C the properties of modified phenolic resin glue can 1500 ¡æ high temperature. The market for good adhesive demand is unceasing growth, so this kind of adhesive has broad prospects for development.
2.2, less pollution
With the increasing deterioration of the global environment, people gradually began to use some environmental protection products. Although not a huge adhesive chemical products, but the hazard to the environment of also nots allow to ignore. Those who blame environmental protection adhesive will be abandoned. Polyethylene formaldehyde adhesive (known as "107 glue") because it contains the free formaldehyde, endanger human body health. In the developed countries have already banned, but in our country because of its low prices, so there is still quite a share of the market. But its dosage has gradually reduce, soon will all washed out. How to through the modification to the environmental protection of the adhesives into environmental protection adhesive is imperative for work. Japan DJK company has a successful study instead of plywood manufacturing is not included in the glue of formaldehyde. DJK company says, usually the urea formaldehyde and honey amine adhesives can cause human body contains formaldehyde of an allergic reaction, DJK says the bond strength, water resistance and cost and honey close amine adhesives. In the environmental protection of the backlash today, more and more people begin to be devoted to the development of biodegradable adhesive. The biodegradable polymer is through the hydrolysis and oxidation to finish. Most of the degradation of the polymer in its main chain containing biodegradable groups, such as amino, hydroxyl, urea and etc. Sharak, etc with a hydroxyl and ether reaction, synthesis of methyl of hydroxyl polyester containing as a matrix, the production of the biodegradable materials, they also with contain group of butyric acid ester, e acid ester, cellulose and starch ester as a matrix, with sucrose ester as viscous agent, the production of biological degradation or hydrolysis can adhesives. In addition, Kauffman, etc. To starch or preparing sulphonated ester as matrix, add contains the polarity of waxy, containing the polarity of the production, the water sensitive adhesive, can in water under the function of hydrolysis happened, in abandoned processing reduce or eliminate pollution to the environment
2.3, adhesive without destructive
The connection of the material basically has bolt connection, riveting, welding and adhesive, use bolt connection technology can be realized though quick connection, but due to material components punch or local heating and on the material to destroy, and in use can't avoid stress concentration. In contrast, adhesive technology is a non destructive connection technology, and for bonding interface overall bear a heavy load and improve load capacity and prolong the life.
2.4 light sex
The density of adhesive small, mostly in 0.9 ~ 2 between, about is the metal or inorganic material density of 20% ~ 25%, and therefore can be greatly reduced by the weight of the object connect glue material. This in the aerospace, aviation, missiles, cars and even, navigation, all have reduce weight, saving energy the important value.
3, the application of adhesive
In addition to the traditional application adhesive bonding outside and some new, clever application.
3.1, corrosion resistance
At present, the steam pipe of the ship's used more bag guisuanlu: plus asbestos to achieve adiabatic goal, but because of cold and heat leakage or alternate produce condensate, gathered in the bottom of the steam pipe wall outside; And the steam pipe by high temperature for a long time, the role of the soluble salt, outside wall corrosion is very serious. This can be in aluminum silicate bottom water glass series adhesives for coating materials, form the kind of enamel structure apply layer, the thermal expansion coefficient and similar pipe, heat stress is small, not cracked. In machinery installation, component is often used to bolt. The bolt devices long-term exposure to air, will produce the crevice corrosion. In the mechanical work process, sometimes because of the severe jolt is loose. In order to solve the problem, can in machinery installation in connection with the first component inorganic adhesive bonding, and then bolted connection. Such already has the function of the reinforced, and can have the effect of corrosion.
3.2, used as a biomedical
Material hydroxyapatite Ca10 (PO4) 6 (OH) 2 (hereinafter referred to as HA) biological ceramic composition of the close to human bone inorganic composition, have good biocompatibility, can and bone formation firm chemical combination with, is the ideal hard tissue replacement materials. But at present of the preparation of the common implants HA elastic modulus high and low intensity, and activity is not ideal. Choose phosphate glass adhesive, through the adhesive role will HA raw materials powder sintering temperature in less than traditional adhesive together, which reduces the elastic modulus, and to ensure the material activity. Cohesion technology Co., LTD. Announced recently that they developed a can be used in the heart of the Coseal adhesive sealing glue, and have been successfully used in clinical. In Europe through the 21 cases of heart surgery compared use to find out, use Coseal surgery than other methods significantly reduce the operation adhesion, and then in the early period of the clinical studies showed that, Coseal seal glue in heart, gynecology and in abdominal surgery are huge potential [13]. In the application of adhesive medicine was known as the new growth point of adhesive industry. Epoxy resin or unsaturated polyester structure composed of glue. Contemporary defense technology, stealth submarine is one of the symbols of the navy equipment modernization. Submarine stealth a important method is in a submarine shell laying silencing watts. Silencing watts is one kind has sound-absorbing properties of rubber. To realize the silencing watts and boat wall of steel plate solid combination, is dependent on adhesive.
3.3, used in military field in military field, adhesive is also widely used.
3.3.1, tanks maintenance
Tank engine shell crack defects is a common disease. Because of the metal structure defects, stress concentration, fatigue, outstanding external force, often cause the body shell launched a different part of the crack. If use of welding methods to solve this kind of problem, existing material will become fragile, deformation, dropping the strength of its loss even at the same time electric energy and equipment. And use special adhesive technology to deal with this kind of crack, will make fast, good, the effect of the province.
3.3.2, army boat assembly
Military boat is used mostly one-time bonding glass fiber (or fiber composites) to reduce boat body weight of the strength of the body and improve the boat. Therefore, make this a great deal with FRP boats used the same
3.3.3 trace, used for military aircraft light bombers
Mainly subsonic speed or cross flight, the wing, the thickness of 1.5 mm in the efficiency of the aluminum alloy plate, some only 0.4 ~ 0.8 mm thick, under which strengthen from corrugated profiles. The structure of the thin skinned riveting so it is difficult, and pick up structure with glue, can not only overcome riveting thin skin easy cause deformation, rivets strokes caused by nest the whole strength of the loss, reduce tooling, shorten the assembly cycles, and increase the structure corrosion resistance, resistance to fatigue properties and damaged security. Modern high-performance military aircraft, the wing fuel tank or the whole whole tank sealing need to use adhesive. Body of organic glass cockpit machine with dacron bring the sealing between adhesive, need high performance adhesive.
We are a missile warhead, thermal protection layer adhesive
Missile warheads loaded for resistance of the bad environment, the structure layer (light metals alloy material, special carbon fiber composite materials) and the heat shielding layer (inorganic compound materials, special resin matrix composite materials). Thermal protection layer and the warheads to 2000 ¡æ connection with the temperature around adhesives.
3.3.5, preparation camouflage materials
To the army ground weapons, basically is 8 and 14 ¦Ì m infrared thermography to threats, realize the main ways of infrared stealth is developed with different emission rate of infrared camouflage coatings, through the different emissivity coating, target effectively shape infrared image segmentation, to achieve the target and background in the purpose of fusion. From the research content of infrared stealth coating to see, high transparent adhesive is to take one of the approach, using the resin in 8 and 14 ¦Ì m of infrared atmosphere contains no absorption window groups to achieve adhesive in the infrared window itself low radiation particularity. Radar coating is an electromagnetic wave absorb, reduces the target's radar signal characteristics, which is difficult to find, identify functional material, is the realization of weapon equipment radar invisibility, one of the main ways. It is made up of absorbent and adhesive, adhesive decided the absorption of the physical and mechanical properties of the coating performance and construction.
3.4, prevent terrorism
The national center for keeping the sandia bid on the nuclear warheads and warehouse designed two super adhesive. One kind is to use the pressure of the gun launch adhesive, once immediately contact with air harden, when jet to humans, and the people in it immediately solidification, could not move. Another kind of adhesive in launch out, then like an avalanche buried in the same each other, make it to see things, can not hear the voice to activities, but can keep life breath. If terrorists into warehouses, grab a nuclear warheads according to prevent explosion, the best choice is to engineers use this kind of super adhesive. Can foresee, this kind of super adhesive in the future will be a battlefield useful.
4, the trend of the development of adhesive
1) the development of adhesive without solvent. The current many adhesive are contains a large number of volatile strong solvents, these solvent not only harm people's physical and mental health, and will damage the ozone layer in the atmosphere. In recent years, cause the attention of the public and the government, so that natural adhesive industry to bring a new tendency, namely to adhesive without solvent development.
2) development nano adhesive. Nano adhesive materials field is an important part of the nanometer adhesive development, could be swept across the global "nano economy" urgent fight, rob a technical commanding heights. Nano adhesive will become a shining star of the new technology.
3) development multi-function adhesive. When a adhesive also has a variety of functions, the value of its application are often sharply, so multi-function adhesive is one of the development trend of adhesive industry.
4) develop military, national defense with adhesive. Military, national defense development with adhesive is the future war and the fear of the war on terror, need, so it will have great progress.
5, endnotes
To save energy and protect the environment, is the world's research must solve one of the important topics. In order to energy saving, environmental protection, all kinds of the equipment must be light, recycling, high strength, streamlined, etc. In order to improve equipment manufacturing, installation and maintenance of the efficiency, leave no stone unturned to will of the neighbour parts (such as: automobile engine cover of parts) merged into the whole. In order to reach this goal, the adhesive or connection will technology. Because of adhesive has no destructive, strength and so on a series of outstanding advantages, and be widely adopted. Inorganic phosphate kind of adhesive in mechanical processing all kinds of tools and blade, grinding device oil-stone and grinding, measuring stick with the head of the classifier adhesive; Oil instrument of request has the certain strength, high temperature resistant sex, the evaporation of the insulation of the great head adhesive; Rectifier components, bottles, high pressure electromagnetic pipe of the seal, and many other aspects has achieved satisfactory results. Silicate kind of adhesives are widely used in metal, glass, ceramics, inorganic silicate kind of material of adhesive. Organic adhesive and people's production and life more closely, widely used in construction, packaging, light and textile industry, such as shoes every field, can say it with the production of human life. On some occasions adhesive is plays an irreplaceable role. Using high temperature adhesive is to achieve carbon materials do not remove the type of connection is the most effective way. For example, satellites, manned spacecraft in through the thick atmosphere, as the high-speed airflow flush, the surface temperature of 2300 ~ 2600 ¡æ, should be in high temperature resistant ablation material protected, ablation materials metal shell with the connection between the high temperature can only use adhesives. Because with so many adhesive prominent advantages, is increasingly attention by people, in material science has developed into a branch of the independent research direction. Of course, adhesive in some ways there are to be solved, such as high temperature adhesive aggregate high cost of inorganic and organic adhesive pollution problems of traditional, etc. Believe that with adhesive modification work of further thorough, the prospect of adhesive more vast.
