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Discovery of the Century·Polymer Materials Speaking of polymer materials, ordinary people may find them incomprehensible, but in fact they are everywhere around us. Whether it is protein as food or cotton, wool and silk as fabric, they are all natural polymer materials. Even the human body itself is basically composed of various biopolymers. my country once led the world in developing natural polymer materials. The use of polymer materials such as bamboo, cotton, hemp and other fibers to make paper is one of the four great inventions in ancient my country. In addition, the use of polymer materials such as tung oil and lacquer as paints and coatings to make lacquer products is also a traditional technology in ancient my country. Polymers are organic compounds with sufficiently high molecular weight composed of carbon, hydrogen, oxygen, silicon, sulfur and other elements. It is called a polymer because of its high molecular weight. The molecular weight of commonly used polymer materials ranges from hundreds to millions. The effect of high molecular weight on the properties of the compound is that it has a certain strength and can be used as a material. This is also where polymer compounds differ from general compounds. And because polymer compounds generally have a long chain structure, each molecule is like a long line. Many molecules are gathered together to form an inseparable thread. This is the fundamental reason why polymer compounds have high strength and can be used as structural materials. On the other hand, people can also use various means, physical or chemical methods, or make physical or chemical changes occur after polymers interact with other substances, so that polymer compounds can become functional polymer materials that can complete special functions. Functional polymer materials mainly include physically functional polymer materials and chemical functional polymer materials. The former include conductive polymers, polymer semiconductors, photoconductive polymers, piezoelectric and thermoelectric polymers, magnetic polymers, optically functional polymers, liquid crystal polymers and information polymer materials, etc. ； The latter include reactive polymers, ion exchange resins, polymer separation membranes, polymer catalysts, polymer reagents, and artificial organs. In addition, there are biological functional and medical polymer materials, such as biopolymers, simulators, polymer drugs, and artificial bone materials. Roughly speaking, polymers can be divided into natural polymers and synthetic (artificial) molecules. Artificial polymers are not very old. It was not until the mid-19th century that humans began to chemically modify and apply natural polymers, and then developed into the artificial synthesis of polymers, which mainly include rubber, fiber and plastics. (1) Utilization, development and modification of natural rubber. In Central and South America, around the 15th century, locals used natural rubber to make games and daily necessities such as containers and rain gear. In the 18th century, the French discovered that there were wild rubber trees in the Amazon River in South America. The word "rubber" in the local Hindi language means "tears of wood". When the bark of a rubber tree is cut, latex will flow out, which was later called natural rubber. In the mid-19th century, the British took the seeds of the rubber tree and successfully planted them in Ceylon (Sri Lanka), and gradually expanded to places such as Malaysia and Indonesia. However, in the manufacture of natural rubber products, how to dissolve and process the raw rubber is a big problem. It was not until the 1840s that Americans discovered that they could use turpentine, sulfur and lead carbonate to heat together to obtain non-stick and elastic products, the so-called vulcanization technology. Therefore, by around 1920, the export volume of natural rubber in Asia reached more than 700,000 tons, which was the same as the export volume of wild rubber in Brazil at that time. (2) Modification of natural cellulose. In the 19th century, the Germans began to use nitric acid to dissolve cotton fiber. As a result, it could be spun or filmed, but it was easy to burn. Finally, it was used to make smokeless products. * * . If camphor is added to it, it can be processed into a plastic called "celluloid", which can be used to make photographic negatives or film films, but is also flammable. In addition, this process is also used in automobile body spray paint. Later, the British treated cotton fiber with sodium hydroxide to obtain mercerized fiber, and then dissolved it with carbon disulfide and spun it to make viscose fiber. Wood pulp could also be used to make cords, cellophane, and rayon. However, in the late 1980s, due to carbon disulfide pollution problems, manufacturers had to find other methods, and most factories stopped production. In addition, the Germans used acetic anhydride to esterify cellulose to obtain acetate fiber. Since it is not easy to burn, it is mostly used in photographic negatives and film films. It can also be used in aircraft fuselage coatings or re-spun into rayon fabrics. (3) The earliest plastic. At the beginning of the 20th century, Americans used phenol and formaldehyde to react to obtain phenolic resin, which can be used as electrical insulation equipment. This was the earliest synthetic polymer. At the same time, the Russians used alcohol to make butadiene, and then used sodium to polymerize it into rubber. After World War II, the Germans and Americans developed a very important type of synthetic rubber, namely styrene-butadiene rubber, which is a copolymer of butadiene and styrene. Despite the important achievements in the above aspects and the establishment of industry, the structures of natural polymers and synthetic polymers were not clear at that time. Therefore, the polymerization reaction process was also not understood. At the beginning of the 20th century, people had confirmed the molecular formula of starch and knew that glucose could be obtained after its hydrolysis. But it is not known how the molecules are connected, so starch is thought to be an association of glucose or its cyclic dimer. Similarly, scientists know that isoprene can be obtained from the cleavage of natural rubber, but they do not know how they are connected and its terminal structure, because it is also believed to be an association of dimeric ring structures. The development of science and technology has made it possible for scientists to use physical chemistry and colloidal chemistry methods to study the structure of natural and laboratory-synthesized polymer substances. After nearly 10 years of research, the German physical chemist Staudinger believes that polymer substances are macromolecular compounds composed of monomers with the same chemical structure connected together by chemical bonds through chemical reactions (polymerization). This is where the term polymer or polymer comes from. When Staudinger announced this view at the German Annual Meeting of Physics and Colloidal Chemistry in 1928, he was opposed by most colleagues and was not recognized. But the truth is on Staudinger's side. After two years of experimental verification, in 1930, when Staudinger once again explained his polymer concept at the German Annual Meeting of Physics and Colloidal Chemistry, he succeeded. So far, after more than 10 years of debate, the scientific concept of polymers has been established. He further clarified the quantitative relationship between the viscosity and molecular weight of dilute solutions of polymers, and published a treatise on organic polymers in 1932, which was later recognized as a sign of the establishment of polymer chemistry as an emerging discipline. In recognition of Staudinger's achievements, the Royal Swedish Academy of Sciences awarded him the 1953 Nobel Prize in Chemistry. A strong confirmation of the concept of macromolecules is that in 1935, the American DuPont Company announced the condensation polymerization of hexamethylenediamine and adipic acid to form a high-molecular polyamide, namely nylon 6-6, which was industrialized in 1938. This is the well-known nylon stocking material. In addition, what is little known is that the parachutes used by the US military in the late World War II were made of this nylon 6-6 material. In the 1940s, free radical-initiated polymerization of vinyl monomers developed rapidly, and industrialization included vinyl chloride, polystyrene, and organic glass. This was a period of vigorous development of synthetic polymers. In the 1950s, alpha-olefins obtained from petroleum cracking mainly included ethylene and propylene. The German Ziegler and the Italian Natta respectively invented the polymerization of polyethylene using metal complex catalysts, namely low-pressure polyethylene and polypropylene. The former was industrialized in 1952 and the latter in 1957. This was a historic development of polymer chemistry, because it was possible to build a large plant with an annual output of 100,000 tons using petroleum as raw material. Both of them later won the Nobel Prize. In the 1960s, research on high-temperature polymers arose due to the need to fly to the moon. The definition of high temperature resistance is that the material can be used for one month in a nitrogen atmosphere at 500 degrees Celsius. ； In the air, it can be used for one month in an environment of 300 degrees Celsius. The results are mainly divided into two categories. One is the polymer Nomex obtained by the condensation polymerization of aromatic polyamides such as phenylenediamine and isophthalyl, which was used as a raw material for space suits at the time. There is also the polymer Kevlar obtained by the condensation of p-phenylenediamine and terephthaloyl chloride. It is a high-temperature-resistant polymer liquid crystal and is now used in composite materials for supersonic aircraft. The other type is heterocyclic polymers, such as polyarylimide and polybenzimidazole as high-temperature adhesives, which have laid the foundation for the materials needed for current aerospace flights. Because polymer materials have many excellent properties, are suitable for modern production, have significant economic benefits, and are not restricted by region or climate, the polymer materials industry has achieved rapid development. Currently, the annual output of synthetic polymer materials in the world has exceeded 140 million tons. Today, polymer materials are no longer substitutes for traditional materials such as metal, wood, cotton, linen, and natural rubber, but are one of the basic materials in the national economy and national defense construction. At the same time, the three major components of polymer science - polymer chemistry, polymer physics and polymer engineering have also become increasingly mature. Polymer materials include plastics, rubber, fibers, films, adhesives and coatings. Among them, plastics, synthetic fibers and synthetic rubber, known as the three major synthetic materials of modern polymers, have become * * It is an indispensable and important material in construction and people's daily life. Due to the gradual reduction of petroleum resources, people are actively considering the development of other energy sources, such as solar energy, hydrogen energy and atomic energy. However, it must also be noted that the main use of petroleum is as fuel. Only 7% is used in the chemical industry, of which only 5% is used as polymer raw materials. Therefore, it is generally believed that even in the next century, the main raw materials of polymers can still come from petroleum. On the other hand, special oil field polymers are very effective in secondary or tertiary oil recovery, which is very helpful for petroleum energy development. Material polymers have a special status in the field of materials, especially in transportation vehicles. They can replace heavy metals and ceramics, as well as wood and other natural materials. For example, 50% of automobile body and shell structural materials already use polymer materials, and this will increase to 70% to 100% in the next century. Another example is aerospace and aviation fuselages and wings. Reducing weight can * * It is fuel-efficient, so polymer composite materials are used, from 30-40% of the total weight in the 1980s to 50-60% in the 1990s, and it is estimated that it can reach 70-80% in the 21st century. Living polymerization is the basis for promoting polymer chemistry to a new era. To carry out living polymerization, the initiation speed must be fast, without chain transfer and chain termination. Laboratory measurement of living polymerization starts from three aspects. First, the conversion rate is directly proportional to the monomer concentration and inversely proportional to the catalyst concentration. ； Second, the molecular weight of high molecular weight is directly proportional to the conversion rate or time. ； Third, the molecular weight distribution should be narrow, about 1.2. At present, both positive ion living polymerization and negative ion living polymerization have been carried out, and the olefin earth catalyst used in the living polymerization of complex-catalyzed polyolefins has already begun to be used. Only free living polymerization has not yet reached the level of application. Some people say that polymer chemistry is a queuing chemistry. The leader of the queue must stand up quickly, and the team members quickly line up. They are facing the same direction. All team members must line up. The result is that the length of each row is the same, that is, the molecular weight distribution is 1, and the conversion rate is 100%. This means that in the new era of polymer materials, there are the following three important aspects:: First of all, the concept of molecular weight of polymers will be completely changed, because the original molecular weights of polymers were all average values, mainly because of the uneven length. ； Secondly, the concept of polymers will also be completely changed. Polymers are by no means composed of molecules of uneven lengths that are difficult to control, but are composed of uniform polymers. ； Finally, there are polymer properties and processing applications. Because they are precision polymers, there will be new data, new properties, processing methods and uses. The so-called polymer materials mainly include three major synthetic materials: plastics, rubber and fibers, of which plastics account for 80% of the total. General polymers account for 80% of plastics, including high-pressure polyethylene, low-pressure polyethylene, polypropylene, polyvinyl chloride and polystyrene. In the hands of scientists, the engineering plastics family was born. Its members include nylon, polycarbonate, polyester and polyphenylene ether that can withstand high temperatures of 100-160 degrees Celsius. In the 1990s, so-called high-temperature engineering plastics such as polyethersulfone, polyphenylene sulfide, polyetherether and polyimide were developed with higher heat resistance of 200-240 degrees Celsius. At the same time, there is also the establishment and development of composite materials, such as composite materials that began to use glass fiber and developed into high-temperature-resistant composite materials using carbon fiber. Non-structural polymer materials and functional polymers have also achieved great development. Since the 1980s, polymer adhesives and paints and coatings have also developed in the direction of high temperature resistance, that is, polymers have developed from structural to non-structural materials. What is more important is the multi-faceted development of functional polymers, such as the use of adsorption properties as seawater desalination and other chemical functional polymers such as ion exchange resins and separation membranes. ； Photofunctional polymers used in optical fibers and photoresists ； Electrical functional polymers with conductive properties and medical functional polymers used as artificial organs and drug controlled release. Because the rise of functional polymers is a very important development since the 1980s. Silicon-based polymer materials replace carbon polymer materials and become a new generation of functional materials. A new material composed of four elements, oxygen, carbon, deuterium and silicon, developed by Nippon Telegraph and Telephone Company, does not melt at 500 degrees Celsius. It can be used to make optical devices without reducing the function due to changes in refractive index. Some * * Leaders in and around the world have increasingly deepened their understanding of the basic status of materials science and realized that the technical feasibility and progress of many industries basically depend on the development of corresponding materials, and the selection of materials is related to issues of improving production efficiency, reducing costs and improving quality. Based on this understanding, they increased their investment in new material research. The U.S. Council on Competitiveness ranks materials technology first among the 60 key technologies that should be supported. ； A large-scale research and development plan for new materials, including polymer materials, is currently being implemented in the UK. The IDMAT new material research and development plan determined by France is 11 * * The focus of the plan. Russia's recently adopted "Special Plan for Priority Research and Development of Civilian Science and Technology in the Russian Federation for 1996-2000" includes the research and development of new materials as a priority area. ； Japan is actively implementing a 10-year (from 1991) new polymer materials research plan. Even Taiwan has regarded the development of advanced materials as a "key among key points" among 69 key technologies. In the 1990s, Japan's annual investment in new materials development and research was 50% higher than that of the United States, and its manpower investment was nearly double that of the United States. Since 1991, Japan has invested a total of approximately 250 billion yen in a 10-year research plan aimed at developing innovative materials. The European Union's investment in materials science accounts for 16% of its total investment in the Fourth Scientific Research Framework Plan, second only to investment in information technology and energy technology, reaching 1.707 billion European currency units. Guo Weiqing from the British Raychem Research Institute pointed out at the 3rd Annual Materials Science Conference of Chinese Scholars in the UK that as an important branch of materials science, the development of polymer materials and technology is particularly rapid. The wide application of polymer materials in many industries has made the materials an indispensable part of economic development. China's polymer materials shine. The progress of domestic polymer materials continues to be reported in the press. Xinhua News Agency reported: * * “The key scientific and technological research project of the Eighth Five-Year Plan, "Special resin materials and processing technologies for polyethersulfone, polyetherether, double-horse polyimide, etc." was approved in Chengdu by * * Acceptance by an acceptance committee composed of relevant departments. Special engineering plastics such as polyethersulfone, polyetherethersulfone, and bismuth polyimide are new polymer materials developed in the 1960s. Due to the excellent comprehensive properties of this type of material, it has now become a reliable guarantee for various space vehicles and new transportation vehicles to achieve high speed, light weight, and increased range. It is also an indispensable new material for electronic and electrical products to achieve large capacity, high integration, and miniaturization. This key project was jointly undertaken by 10 units including Sichuan Union University, Beijing Research Institute of Chemical Industry, and Dongfang Insulation Materials Factory. After five years of cooperation among more than 120 scientific and technical personnel, the task was fully completed and 27 appraisal results were obtained. Among them, the "polyether ether resin" developed by Professor Wu Zhongwen of Jilin University and others has reached the current international advanced level in performance and low cost. * * Lower than similar foreign products ； The "Synthesis of Heterocyclic Substituted Diphenyl Polyethersulfone" developed by Professor Jian (Tang Quxunjia) Gao of Dalian University of Technology and others has reached the international advanced level in its main economic and technical indicators. ； The "double-horse type polyimide aviation tooling mold material" developed by Professor Jiang Luxia of Sichuan Union University, Chengdu Aircraft Industry Company, Dongfang Insulation Materials Factory, etc. is in a leading position in the country and has reached the international level in the late 1980s. At present, a variety of products have formed large-scale production capabilities, providing 15 new products of special engineering plastics, 19 new materials, and 3 new processes. In addition, Xinhua News Agency also reported that a new type of UV-curable coating for home appliances - JD-1 UV-curable resin, was successfully developed in Changsha City, Hunan Province and passed the appraisal under the title "my country's polymer chemistry research has made a major breakthrough". Experts believe that it fills a domestic gap and reaches the advanced level of similar foreign products. Hunan Yada Polymer Chemical Factory Co., Ltd., located on the east coast of Changsha City, has been following the trend of high-tech development for many years, constantly researching and developing new technologies with high starting point, high level and high efficiency, and quickly transforming these technological achievements into productivity. The scientific and technological personnel of this company finally developed JD-1 ultraviolet curable resin after thousands of experiments with little funds and poor conditions. Just apply a layer of UV-curable resin on the outside of various home appliances. After some processing, the home appliances are like wearing a "coat" that is as hard as fiberglass and as smooth as a mirror. According to experts, the decoration of the appearance of home appliances is an important indicator to measure their grade. This is a major subject of research in the chemical industry at home and abroad for many years. The successful development of new UV-curable resin will enable us to * * Electric decoration reaches a new level ； At the same time, ending the long history of imports can save a lot of foreign exchange. Experts believe that this is a high-tech product with less pollution and good energy-saving benefits. It has the advantages of impact resistance, aging resistance, and fast curing speed. It can be widely used in refrigerators, washing machines, electrical instruments, telecommunications equipment, automobiles, motorcycles, etc. An internationally leading polymer technology, ultra-high molecular weight polyacrylamide synthesis technology, was successfully developed at the Daqing Oilfield Chemical Plant. Experts say that after the popularization and application of this technology, the amount of polymer used can be reduced by 20%, the crude oil recovery rate can be greatly improved, and the efficiency of oilfield chemical enterprises can be increased by more than 50 million yuan every year. In 1995, with the promotion and application of tertiary oil recovery technology in Daqing Oilfield, the Oilfield Chemical Plant introduced French technology to produce polyacrylamide with a molecular weight of 10-15 million, making my country's polymer production technology enter the world's advanced ranks. However, according to polymer flooding test studies, ultra-high molecular weight polymers with a molecular weight greater than 17 million have better oil displacement effects. In order to speed up the industrial development of ultra-high molecular weight polyacrylamide products, Daqing Oilfield Chemical Plant has carried out scientific and technological research through multi-channel horizontal alliances. In just three months, 14 scientific and technical personnel from the research team successfully synthesized polyacrylamide with a molecular weight of 17 million in industrial trials and achieved satisfactory results in trial production. Currently, this factory has begun mass production of ultra-high molecular weight polyacrylamide products. In addition, "PTC intelligent constant temperature cable", "multifunctional super water-absorbing and water-retaining agent", "fly ash efficient activator", etc. are all outstanding results achieved by my country in the field of polymer materials. In addition, my country’s research on polymer single chain single crystals has achieved internationally leading results.: Successfully prepared single-chain single crystals of butadiene rubber, innovatively conducted research on single-molecule chain glass bodies, and observed a new schlieren structure in the polymer liquid crystal state for the first time. This has caused a sensation in the world's scientific and technological circles. Biscuits Speaking of polymer materials, ordinary people may find them incomprehensible, but in fact they are everywhere around us. Whether it is protein as food or cotton, wool and silk as fabric, they are all natural polymer materials. Even the human body itself is basically composed of various biopolymers. my country once led the world in developing natural polymer materials. The use of polymer materials such as bamboo, cotton, hemp and other fibers to make paper is one of the four great inventions in ancient my country. In addition, the use of polymer materials such as tung oil and lacquer as paints and coatings to make lacquer products is also a traditional technology in ancient my country. Polymers are organic compounds with sufficiently high molecular weight composed of carbon, hydrogen, oxygen, silicon, sulfur and other elements. It is called a polymer because of its high molecular weight. The molecular weight of commonly used polymer materials ranges from hundreds to millions. The effect of high molecular weight on the properties of the compound is that it has a certain strength and can be used as a material. This is also where polymer compounds differ from general compounds. And because polymer compounds generally have a long chain structure, each molecule is like a long line. Many molecules are gathered together to form an inseparable thread. This is the fundamental reason why polymer compounds have high strength and can be used as structural materials. On the other hand, people can also use various means, physical or chemical methods, or make physical or chemical changes occur after polymers interact with other substances, so that polymer compounds can become functional polymer materials that can complete special functions. Functional polymer materials mainly include physically functional polymer materials and chemical functional polymer materials. The former include conductive polymers, polymer semiconductors, photoconductive polymers, piezoelectric and thermoelectric polymers, magnetic polymers, optically functional polymers, liquid crystal polymers and information polymer materials, etc. ； The latter include reactive polymers, ion exchange resins, polymer separation membranes, polymer catalysts, polymer reagents, and artificial organs. In addition, there are biological functional and medical polymer materials, such as biopolymers, simulators, polymer drugs, and artificial bone materials. Roughly speaking, polymers can be divided into natural polymers and synthetic (artificial) molecules. Artificial polymers are not very old. It was not until the mid-19th century that humans began to chemically modify and apply natural polymers, and then developed into the artificial synthesis of polymers, which mainly include rubber, fiber and plastics. (1) Utilization, development and modification of natural rubber. In Central and South America, around the 15th century, locals used natural rubber to make games and daily necessities such as containers and rain gear. In the 18th century, the French discovered that there were wild rubber trees in the Amazon River in South America. The word "rubber" in the local Hindi language means "tears of wood". When the bark of a rubber tree is cut, latex will flow out, which was later called natural rubber. In the mid-19th century, the British took the seeds of the rubber tree and successfully planted them in Ceylon (Sri Lanka), and gradually expanded to places such as Malaysia and Indonesia. However, in the manufacture of natural rubber products, how to dissolve and process the raw rubber is a big problem. It was not until the 1840s that Americans discovered that they could use turpentine, sulfur and lead carbonate to heat together to obtain non-stick and elastic products, the so-called vulcanization technology. Therefore, by around 1920, the export volume of natural rubber in Asia reached more than 700,000 tons, which was the same as the export volume of wild rubber in Brazil at that time. (2) Modification of natural cellulose. In the 19th century, the Germans began to use nitric acid to dissolve cotton fiber. As a result, it could be spun or filmed, but it was easy to burn. Finally, it was used to make smokeless products. * * . If camphor is added to it, it can be processed into a plastic called "celluloid", which can be used to make photographic negatives or film films, but is also flammable. In addition, this process is also used in automobile body spray paint. Later, the British treated cotton fiber with sodium hydroxide to obtain mercerized fiber, and then dissolved it with carbon disulfide and spun it to make viscose fiber. Wood pulp could also be used to make cords, cellophane, and rayon. However, in the late 1980s, due to carbon disulfide pollution problems, manufacturers had to find other methods, and most factories stopped production. In addition, the Germans used acetic anhydride to esterify cellulose to obtain acetate fiber. Since it is not easy to burn, it is mostly used in photographic negatives and film films. It can also be used in aircraft fuselage coatings or re-spun into rayon fabrics. (3) The earliest plastic. At the beginning of the 20th century, Americans used phenol and formaldehyde to react to obtain phenolic resin, which can be used as electrical insulation equipment. This was the earliest synthetic polymer. At the same time, the Russians used alcohol to make butadiene, and then used sodium to polymerize it into rubber. After World War II, the Germans and Americans developed a very important type of synthetic rubber, namely styrene-butadiene rubber, which is a copolymer of butadiene and styrene. Despite the important achievements in the above aspects and the establishment of industry, the structures of natural polymers and synthetic polymers were not clear at that time. Therefore, the polymerization reaction process was also not understood. At the beginning of the 20th century, people had confirmed the molecular formula of starch and knew that glucose could be obtained after its hydrolysis. But it is not known how the molecules are connected, so starch is thought to be an association of glucose or its cyclic dimer. Similarly, scientists know that isoprene can be obtained from the cleavage of natural rubber, but they do not know how they are connected and its terminal structure, because it is also believed to be an association of dimeric ring structures. The development of science and technology has made it possible for scientists to use physical chemistry and colloidal chemistry methods to study the structure of natural and laboratory-synthesized polymer substances. After nearly 10 years of research, the German physical chemist Staudinger believes that polymer substances are macromolecular compounds composed of monomers with the same chemical structure connected together by chemical bonds through chemical reactions (polymerization). This is where the term polymer or polymer comes from. When Staudinger announced this view at the German Annual Meeting of Physics and Colloidal Chemistry in 1928, he was opposed by most colleagues and was not recognized. But the truth is on Staudinger's side. After two years of experimental verification, in 1930, when Staudinger once again explained his polymer concept at the German Annual Meeting of Physics and Colloidal Chemistry, he succeeded. So far, after more than 10 years of debate, the scientific concept of polymers has been established. He further clarified the quantitative relationship between the viscosity and molecular weight of dilute solutions of polymers, and published a treatise on organic polymers in 1932, which was later recognized as a sign of the establishment of polymer chemistry as an emerging discipline. In recognition of Staudinger's achievements, the Royal Swedish Academy of Sciences awarded him the 1953 Nobel Prize in Chemistry. A strong confirmation of the concept of macromolecules is that in 1935, the American DuPont Company announced the condensation polymerization of hexamethylenediamine and adipic acid to form a high-molecular polyamide, namely nylon 6-6, which was industrialized in 1938. This is the well-known nylon stocking material. In addition, what is little known is that the parachutes used by the US military in the late World War II were made of this nylon 6-6 material. In the 1940s, free radical-initiated polymerization of vinyl monomers developed rapidly, and industrialization included vinyl chloride, polystyrene, and organic glass. This was a period of vigorous development of synthetic polymers. In the 1950s, alpha-olefins obtained from petroleum cracking mainly included ethylene and propylene. The German Ziegler and the Italian Natta respectively invented the polymerization of polyethylene using metal complex catalysts, namely low-pressure polyethylene and polypropylene. The former was industrialized in 1952 and the latter in 1957. This was a historic development of polymer chemistry, because it was possible to build a large plant with an annual output of 100,000 tons using petroleum as raw material. Both of them later won the Nobel Prize. In the 1960s, research on high-temperature polymers arose due to the need to fly to the moon. The definition of high temperature resistance is that the material can be used for one month in a nitrogen atmosphere at 500 degrees Celsius. ； In the air, it can be used for one month in an environment of 300 degrees Celsius. The results are mainly divided into two categories. One is the polymer Nomex obtained by the condensation polymerization of aromatic polyamides such as phenylenediamine and isophthalyl, which was used as a raw material for space suits at the time. There is also the polymer Kevlar obtained by the condensation of p-phenylenediamine and terephthaloyl chloride. It is a high-temperature-resistant polymer liquid crystal and is now used in composite materials for supersonic aircraft. The other type is heterocyclic polymers, such as polyarylimide and polybenzimidazole as high-temperature adhesives, which have laid the foundation for the materials needed for current aerospace flights. Because polymer materials have many excellent properties, are suitable for modern production, have significant economic benefits, and are not restricted by region or climate, the polymer materials industry has achieved rapid development. Currently, the annual output of synthetic polymer materials in the world has exceeded 140 million tons. Today, polymer materials are no longer substitutes for traditional materials such as metal, wood, cotton, linen, and natural rubber, but are one of the basic materials in the national economy and national defense construction. At the same time, the three major components of polymer science - polymer chemistry, polymer physics and polymer engineering have also become increasingly mature. Polymer materials include plastics, rubber, fibers, films, adhesives and coatings. Among them, plastics, synthetic fibers and synthetic rubber, known as the three major synthetic materials of modern polymers, have become * * It is an indispensable and important material in construction and people's daily life. Due to the gradual reduction of petroleum resources, people are actively considering the development of other energy sources, such as solar energy, hydrogen energy and atomic energy. However, it must also be noted that the main use of petroleum is as fuel. Only 7% is used in the chemical industry, of which only 5% is used as polymer raw materials. Therefore, it is generally believed that even in the next century, the main raw materials of polymers can still come from petroleum. On the other hand, special oil field polymers are very effective in secondary or tertiary oil recovery, which is very helpful for petroleum energy development. Material polymers have a special status in the field of materials, especially in transportation vehicles. They can replace heavy metals and ceramics, as well as wood and other natural materials. For example, 50% of automobile body and shell structural materials already use polymer materials, and this will increase to 70% to 100% in the next century. Another example is aerospace and aviation fuselages and wings. Reducing weight can * * It is fuel-efficient, so polymer composite materials are used, from 30-40% of the total weight in the 1980s to 50-60% in the 1990s, and it is estimated that it can reach 70-80% in the 21st century. Living polymerization is the basis for promoting polymer chemistry to a new era. To carry out living polymerization, the initiation speed must be fast, without chain transfer and chain termination. Laboratory measurement of living polymerization starts from three aspects. First, the conversion rate is directly proportional to the monomer concentration and inversely proportional to the catalyst concentration. ； Second, the molecular weight of high molecular weight is directly proportional to the conversion rate or time. ； Third, the molecular weight distribution should be narrow, about 1.2. At present, both positive ion living polymerization and negative ion living polymerization have been carried out, and the olefin earth catalyst used in the living polymerization of complex-catalyzed polyolefins has already begun to be used. Only free living polymerization has not yet reached the level of application. Some people say that polymer chemistry is a queuing chemistry. The leader of the queue must stand up quickly, and the team members quickly line up. They are facing the same direction. All team members must line up. The result is that the length of each row is the same, that is, the molecular weight distribution is 1, and the conversion rate is 100%. This means that in the new era of polymer materials, there are the following three important aspects:: First of all, the concept of molecular weight of polymers will be completely changed, because the original molecular weights of polymers were all average values, mainly because of the uneven length. ； Secondly, the concept of polymers will also be completely changed. Polymers are by no means composed of molecules of uneven lengths that are difficult to control, but are composed of uniform polymers. ； Finally, there are polymer properties and processing applications. Because they are precision polymers, there will be new data, new properties, processing methods and uses. The so-called polymer materials mainly include three major synthetic materials: plastics, rubber and fibers, of which plastics account for 80% of the total. General polymers account for 80% of plastics, including high-pressure polyethylene, low-pressure polyethylene, polypropylene, polyvinyl chloride and polystyrene. In the hands of scientists, the engineering plastics family was born. Its members include nylon, polycarbonate, polyester and polyphenylene ether that can withstand high temperatures of 100-160 degrees Celsius. In the 1990s, so-called high-temperature engineering plastics such as polyethersulfone, polyphenylene sulfide, polyetherether and polyimide were developed with higher heat resistance of 200-240 degrees Celsius. At the same time, there is also the establishment and development of composite materials, such as composite materials that began to use glass fiber and developed into high-temperature-resistant composite materials using carbon fiber. Non-structural polymer materials and functional polymers have also achieved great development. Since the 1980s, polymer adhesives and paints and coatings have also developed in the direction of high temperature resistance, that is, polymers have developed from structural to non-structural materials. What is more important is the multi-faceted development of functional polymers, such as the use of adsorption properties as seawater desalination and other chemical functional polymers such as ion exchange resins and separation membranes. ； Photofunctional polymers used in optical fibers and photoresists ； Electrical functional polymers with conductive properties and medical functional polymers used as artificial organs and drug controlled release. Because the rise of functional polymers is a very important development since the 1980s. Silicon-based polymer materials replace carbon polymer materials and become a new generation of functional materials. A new material composed of four elements, oxygen, carbon, deuterium and silicon, developed by Nippon Telegraph and Telephone Company, does not melt at 500 degrees Celsius. It can be used to make optical devices without reducing the function due to changes in refractive index. Some * * Leaders in and around the world have increasingly deepened their understanding of the basic status of materials science and realized that the technical feasibility and progress of many industries basically depend on the development of corresponding materials, and the selection of materials is related to issues of improving production efficiency, reducing costs and improving quality. Based on this understanding, they increased their investment in new material research. The U.S. Council on Competitiveness ranks materials technology first among the 60 key technologies that should be supported. ； A large-scale research and development plan for new materials, including polymer materials, is currently being implemented in the UK. The IDMAT new material research and development plan determined by France is 11 * * The focus of the plan. Russia's recently adopted "Special Plan for Priority Research and Development of Civilian Science and Technology in the Russian Federation for 1996-2000" includes the research and development of new materials as a priority area. ； Japan is actively implementing a 10-year (from 1991) new polymer materials research plan. Even Taiwan has regarded the development of advanced materials as a "key among key points" among 69 key technologies. In the 1990s, Japan's annual investment in new materials development and research was 50% higher than that of the United States, and its manpower investment was nearly double that of the United States. Since 1991, Japan has invested a total of approximately 250 billion yen in a 10-year research plan aimed at developing innovative materials. The European Union's investment in materials science accounts for 16% of its total investment in the Fourth Scientific Research Framework Plan, second only to investment in information technology and energy technology, reaching 1.707 billion European currency units. Guo Weiqing from the British Raychem Research Institute pointed out at the 3rd Annual Materials Science Conference of Chinese Scholars in the UK that as an important branch of materials science, the development of polymer materials and technology is particularly rapid. The wide application of polymer materials in many industries has made the materials an indispensable part of economic development. China's polymer materials shine. The progress of domestic polymer materials continues to be reported in the press. Xinhua News Agency reported: * * “The key scientific and technological research project of the Eighth Five-Year Plan, "Special resin materials and processing technologies for polyethersulfone, polyetherether, double-horse polyimide, etc." was approved in Chengdu by * * Acceptance by an acceptance committee composed of relevant departments. Special engineering plastics such as polyethersulfone, polyetherethersulfone, and bismuth polyimide are new polymer materials developed in the 1960s. Due to the excellent comprehensive properties of this type of material, it has now become a reliable guarantee for various space vehicles and new transportation vehicles to achieve high speed, light weight, and increased range. It is also an indispensable new material for electronic and electrical products to achieve large capacity, high integration, and miniaturization. This key project was jointly undertaken by 10 units including Sichuan Union University, Beijing Research Institute of Chemical Industry, and Dongfang Insulation Materials Factory. After five years of cooperation among more than 120 scientific and technical personnel, the task was fully completed and 27 appraisal results were obtained. Among them, the "polyether ether resin" developed by Professor Wu Zhongwen of Jilin University and others has reached the current international advanced level in performance and low cost. * * Lower than similar foreign products ； The "Synthesis of Heterocyclic Substituted Diphenyl Polyethersulfone" developed by Professor Jian (Tang Quxunjia) Gao of Dalian University of Technology and others has reached the international advanced level in its main economic and technical indicators. ； The "double-horse type polyimide aviation tooling mold material" developed by Professor Jiang Luxia of Sichuan Union University, Chengdu Aircraft Industry Company, Dongfang Insulation Materials Factory, etc. is in a leading position in the country and has reached the international level in the late 1980s. At present, a variety of products have formed large-scale production capabilities, providing 15 new products of special engineering plastics, 19 new materials, and 3 new processes. In addition, Xinhua News Agency also reported that a new type of UV-curable coating for home appliances - JD-1 UV-curable resin, was successfully developed in Changsha City, Hunan Province and passed the appraisal under the title "my country's polymer chemistry research has made a major breakthrough". Experts believe that it fills a domestic gap and reaches the advanced level of similar foreign products. Hunan Yada Polymer Chemical Factory Co., Ltd., located on the east coast of Changsha City, has been following the trend of high-tech development for many years, constantly researching and developing new technologies with high starting point, high level and high efficiency, and quickly transforming these technological achievements into productivity. The scientific and technological personnel of this company finally developed JD-1 ultraviolet curable resin after thousands of experiments with little funds and poor conditions. Just apply a layer of UV-curable resin on the outside of various home appliances. After some processing, the home appliances are like wearing a "coat" that is as hard as fiberglass and as smooth as a mirror. According to experts, the decoration of the appearance of home appliances is an important indicator to measure their grade. This is a major subject of research in the chemical industry at home and abroad for many years. The successful development of new UV-curable resin will enable us to * * Electric decoration reaches a new level ； At the same time, ending the long history of imports can save a lot of foreign exchange. Experts believe that this is a high-tech product with less pollution and good energy-saving benefits. It has the advantages of impact resistance, aging resistance, and fast curing speed. It can be widely used in refrigerators, washing machines, electrical instruments, telecommunications equipment, automobiles, motorcycles, etc. An internationally leading polymer technology, ultra-high molecular weight polyacrylamide synthesis technology, was successfully developed at the Daqing Oilfield Chemical Plant. Experts say that after the popularization and application of this technology, the amount of polymer used can be reduced by 20%, the crude oil recovery rate can be greatly improved, and the efficiency of oilfield chemical enterprises can be increased by more than 50 million yuan every year. In 1995, with the promotion and application of tertiary oil recovery technology in Daqing Oilfield, the Oilfield Chemical Plant introduced French technology to produce polyacrylamide with a molecular weight of 10-15 million, making my country's polymer production technology enter the world's advanced ranks. However, according to polymer flooding test studies, ultra-high molecular weight polymers with a molecular weight greater than 17 million have better oil displacement effects. In order to speed up the industrial development of ultra-high molecular weight polyacrylamide products, Daqing Oilfield Chemical Plant has carried out scientific and technological research through multi-channel horizontal alliances. In just three months, 14 scientific and technical personnel from the research team successfully synthesized polyacrylamide with a molecular weight of 17 million in industrial trials and achieved satisfactory results in trial production. Currently, this factory has begun mass production of ultra-high molecular weight polyacrylamide products. In addition, "PTC intelligent constant temperature cable", "multifunctional super water-absorbing and water-retaining agent", "fly ash efficient activator", etc. are all outstanding results achieved by my country in the field of polymer materials. In addition, my country’s research on polymer single chain single crystals has achieved internationally leading results.: Successfully prepared single-chain single crystals of butadiene rubber, innovatively conducted research on single-molecule chain glass bodies, and observed a new schlieren structure in the polymer liquid crystal state for the first time. This has caused a sensation in the world's scientific and technological circles. This post was last edited by QXZ-1966 on 2009-2-9 20:27 ]