Graduation thesis of polymer materials 1
Analysis of polymer material forming technology.
Polymer material forming technology has developed rapidly in industry. This paper introduces the development of polymer material forming technology, discusses its innovative research, and expounds the development trend of polymer material forming technology in detail.
Polymer materials; Forming processing; technology
In recent years, the development of some special fields such as aviation industry and national defense cutting-edge industry has put forward higher requirements for the high strength, high modulus and light weight of polymer materials, and it has become more and more urgent to develop high-strength polymers with various specific requirements.
First, the development of polymer material molding technology
In the past 50 years, the polymer synthesis industry has made great progress. For example, the structure of the extruder for granulation has been greatly improved, and the output has been greatly improved. In 1960s, single-screw extruder was mainly used for granulation, and the output was about 3t/h; From 1970s to 1980s, continuous mixer and single screw extruder were used for granulation, and the output was about10t/h; Since the mid-1980s. Using twin-screw extruder and gear pump for granulation, the output can reach 40-45t/h, and the future development direction is that the output can reach 60 t/h. ..
1950, the annual output of plastics in the world is 2 million tons. In the 1990s. The average annual growth rate of plastic output is 5.8%, and it will increase to 65.438+0.8 billion t from 2000 to 2065.438+00, and the global plastic output will reach 300 million t. In addition, the recent shock absorption in the synthetic industry makes the molecular structure of resin easy to control and accelerates large-scale low-cost production. With the development of automobile industry, the requirements of energy saving, high speed, beauty, environmental protection, comfortable ride, safety and reliability are becoming more and more important. The continuous expansion of automobile scale and the improvement of performance have promoted the development of parts and related materials industry. In order to reduce the cost of the whole vehicle and increase the effective load of the vehicle itself, it is very important to increase the use of plastic materials in the vehicle.
It is reported that 100kg plastic parts on automobiles can replace traditional automobile materials (such as steel, etc.). ) That originally required 100-300kg. Therefore, more and more metal parts in cars are replaced by plastic parts. In addition, about 90% of auto parts need to be molded by molds. For example, making an ordinary car requires 1200 sets of molds. In developed countries such as the United States and Japan, more than 50% products in the mold industry are molds for automobiles.
At present, the main goals of polymer material processing are high productivity, high performance, low cost and fast delivery. Products are developing in the direction of small size, thin wall and light weight; In terms of molding processing, it has changed from large-scale to multi-variety with short research and development cycle, and has developed in the direction of low energy consumption, full recovery and zero emission.
Secondly, the innovative research on the molding and processing technology of polymer materials today.
(A) polymer dynamic reaction processing technology and equipment
Polymer reactive processing technology is developed on the basis of existing twin-screw extruder. A 10-screw extruder for continuous reaction and mixing has been developed by foreign Berstart company, which can solve the problems existing in other extruders (including twin-screw extruder and four-screw extruder) as reactors. The research and development of reactive molding processing technology in China is still in its infancy, but China's economic development strongly requires the great development of polymer reactive molding processing technology. The key technology of continuous production of polycarbonate (PC) and nylon by exchange method is the reactive extrusion equipment of polycondensation reactor, and China produces tens of millions of tons of modified polymers and their alloy materials every year. The key technology is also reactive extrusion technology and equipment.
At present, the reaction treatment equipment used at home and abroad are all products of traditional mixing and stirring equipment in principle, and there are problems such as heat transfer, mass transfer, mixing and chemical reaction, and uncontrollable molecular weight and distribution of reaction products. In addition, the high equipment investment cost, high energy consumption, loud noise and difficult sealing are also the defects of traditional reaction treatment equipment. The polymer dynamic reactive processing technology and equipment are completely different from the traditional technology in reaction processing principle and equipment structure. This technology introduces the mechanical vibration field caused by electromagnetic field into the whole process of polymer reactive extrusion, so as to control the chemical reaction process, the condensed structure of reaction products and the physical and chemical properties of reaction products.
Firstly, this technology breaks through the difficulty of controlling the mixing process and residence time distribution of polymer monomers or prepolymers in theory, solves the problems of mass, momentum and energy transfer and balance in the polymer reaction process under the action of vibration force field, and technically solves the problem of equipment structure integration. The new equipment has the advantages of small size, light weight, low energy consumption, low noise, controllable product performance, good adaptability and high reliability. These advantages are unmatched by traditional technology and equipment or incomparable at all. This new technology makes China's polymer reactive processing technology directly at the forefront of the world technology and in a leading position in this field.
(2) New material preparation technology based on dynamic reactive processing equipment.
1. Direct synthesis reaction molding technology of information storage optical disk substrate. This technology overcomes the problems of many intermediate links, long cycle, high energy consumption, easy pollution during storage and transportation, complex pretreatment before molding and so on. It integrates PC resin production, intermediate storage and transportation, and disc-based molding into one, and combines the dynamic continuous reaction molding technology to study the continuous production technology of transesterification and develop the precise injection molding equipment for optical discs, so as to achieve the purpose of saving energy, reducing consumption and effectively controlling product quality.
2. The new technology of preparing polymer/inorganic composites by physical field strengthening. This technology designs the surface characteristics and functions (particle design) of inorganic particles under the action of strong vibration shear force field. In the designed continuous processing environment, the continuous preparation of polymer/inorganic composites is realized by in-situ modification, in-situ coating and forced dispersion of inorganic particles through polymers without adding or adding other chemical modifiers.
3. Dynamic full vulcanization preparation technology of thermoplastic elastomer. This technology introduces the vibration force field into the whole process of mixing and extrusion, controls the vulcanization and straightening process, realizes the dynamic full vulcanization of rubber phase in the mixing process, and solves the phase inversion problem of mixed phase in the mixing process. The dynamic vulcanization technology and equipment of thermoplastic elastomer with independent intellectual property rights have been developed, which has improved the technical level of TPV in China.
Third, the development trend of polymer material molding technology
In recent years, the national engineering research centers of new molding equipment have successfully completed the national torch plan and the national? Eight-five? 、? Ninth Five-Year Plan? At the same time, we attach great importance to the transformation and industrialization of scientific and technological achievements, complete supporting projects of more than 20 industrialization projects, and set up Guangzhou Huaxinke Machinery Co., Ltd. and Beijing Huaxinke Plastic Machinery Co., Ltd., so that their new technologies and equipment with independent intellectual property rights can be popularized and applied at home and abroad. Plastic electromagnetic dynamic plasticizing extrusion equipment has formed 7 specification series, and nearly 800 sets have been popularized and applied in more than 20 provinces, municipalities and autonomous regions in China in recent two years. Sales exceeded/kloc-0.50 billion yuan, and some new equipment was sold to the Netherlands, Thailand, Bangladesh and other countries, resulting in good economic and social benefits.
For example, in 2000 and 20001year, only Guangdong's PE electromagnetic dynamic foam sheet production line saved the country nearly160,000 US dollars in foreign exchange, and each production line could save the product factory 2 1 10,000 K per year. The electromagnetic dynamic injection molding machine for plastics has developed and perfected five specification series and put them into mass production and put them into the market. The pilot test and industrialization of electromagnetic dynamic mixing extruder for plastics have been completed, and four developed specifications are being put into production for trial use. At present, there is a good demand for new equipment in the market. The National Engineering Research Center of New Polymer Molding Equipment is reorganizing Guangzhou Huaxinke Machinery Co., Ltd. ... to combine technology and capital, introduce new management and market mechanism, and strive to achieve annual sales of new equipment of over 100 million in two or three years. China has joined the WTO, and all industries will face severe challenges.
To sum up, China must take the road of developing polymer material molding technology and equipment with China characteristics, break the technical blockade of foreign countries and realize the transformation from tracking to leaping; Grasp the forefront of technology and cultivate independent intellectual property rights. It is the only way to promote the combination of scientific research and industry, accelerate the process of transforming achievements into productive forces, and accelerate the development of high-tech polymer material molding and processing and its industry in China.
References:
[1]Chris Rauwendaal, polymer extrusion, Karl Hansel publishing house, Munich /FkG, l999.
Theory and technology of dynamic plasticization of polymers [M]. Beijing Science Press 200547435.
Qu, polymer electromagnetic dynamic plasticizing extrusion method and equipment [J]. China patent 9O 10 1034.0, I990 US patent 52 17302, 1993.
Graduation thesis of polymer materials II
Development prospect of polymer materials
Abstract: With the development of production and technology, and people's pursuit of knowledge, various new requirements are put forward for the properties of polymer materials. In modern times, polymer materials, like metal materials and inorganic nonmetal materials, have become important materials in science and technology and economic construction. This paper mainly analyzes the development prospect and trend of polymer materials.
Key words: polymer materials; Development; prospect
Development status and trend of a polymer material
As an important material, polymer materials have played a great role in various industrial fields after about half a century's development. From the point of view that polymer materials are closely related to national economy, high technology and modern life, mankind has entered the polymer age. Polymer materials industry should not only provide a large number of new products and materials with large quantity, wide range and rapid change for industrial and agricultural production and people's life, but also provide more and more effective high-performance structural materials and functional materials for the development of high technology.
In view of this, China's polymer materials should focus on developing engineering plastics, composite materials, liquid crystal polymer materials, polymer separation materials and biomedical polymer materials on the basis of further developing general polymer materials, improving technical level and expanding production to meet market demand. In recent years, with the development of cutting-edge technologies such as electric power, electronics, information, automobiles, aviation, aerospace and ocean development, we should make progress in order to meet the needs of this development? With the further development, polymer materials become more and more active in the continuous transformation to high functionality and high performance, and have made a major breakthrough.
Second, the application of polymer materials in various fields
Application of 1 polymer materials in machinery industry
Polymer materials are more and more widely used in machinery industry. Replace steel with plastic? ,? Plastic instead of iron? It has become the hot spot and focus of current material science research. This research broadens the range of material selection, and makes mechanical products change from traditional safety, bulkiness and high consumption to safety, portability, durability and economy. For example, the wear resistance of polyurethane elastomer and polyurethane vinegar elastomer is particularly prominent. In some organic solvents such as kerosene and mortar mixture, its wear resistance is lower than other materials. Polyurethane elastomer can be made into impeller and cover plate of flotation machine, which is widely used in flotation machine with abrasive wear. Another example is polyoxymethylene, which has outstanding wear resistance and is less than nylon's year-on-year wear on metal. Modified with PTFE, engine oil, disulfide bonds and chemical lubrication, the friction coefficient and wear amount are smaller. Because of its good mechanical properties and wear resistance, polyoxymethylene is widely used to manufacture various gears, bearings, cams, nuts, various pumps and structural parts of guide rails. In the automobile industry, it can replace non-ferrous metals such as zinc, copper and aluminum, as well as cast iron and steel stamping parts.
Application of polymer materials in fuel cells
The thickness of polymer electrolyte membrane has great influence on the performance of battery. Reducing the thickness of the membrane can greatly reduce the internal resistance of the battery and obtain a large power output. The skeleton structure of perfluorosulfonic acid proton exchange membrane has good mechanical strength and chemical durability. Fluoride compounds have the characteristics of monk water, and water is easy to be discharged. However, when the battery is running, the water retention rate decreases, which will affect the conductivity of the electrolyte membrane. Therefore, the reaction gas should be humidified. The humidification technology of polymer electrolyte membrane ensures the excellent conductivity of the membrane, but it also brings problems such as the increase of battery volume, complex system and water management in low temperature environment. At present, a number of new polymer materials, such as enhanced perfluorosulfonic acid polymer proton exchange membrane, high temperature resistant aromatic heterocyclic sulfonic acid polymer electrolyte membrane, carbon nanofiber material and a new conductive polymer material, have attracted researchers' attention.
Application and development of polymer materials in modern agricultural seed treatment
Application of polymer materials in modern agricultural seed treatment: The chemical treatment of new generation seeds can generally be divided into physical wrapping, which uses dry and wet polymer film forming agents to wrap seeds. Seed surface coating is to wrap pesticides and other components on the seed surface with polymer film forming agent. Physical granulation of seeds: mixing seeds with other polymer materials for granulation to improve the appearance and shape of seeds and facilitate mechanical sowing. Research and development progress of polymer materials for modern agricultural seed treatment: polymer materials for seed treatment have gradually developed from petroleum polymer materials to natural and functional polymer materials. Among them, the more common and important types of polymer materials are polysaccharide natural polymer materials, polymer materials with good membrane performance at low temperature, super absorbent materials, temperature-sensitive materials, natural polymer materials developed by comprehensive utilization of natural biological resources, etc., among which the seed coating agent with sustainable biological resources is particularly eye-catching.
Application of Polymer Materials in Intelligent Stealth Technology
Intelligent stealth material is a kind of functional material developed with the development of intelligent materials and the demand of equipment stealth. It has the functions of sensing external signals and processing information. Materials/systems that can automatically adjust their own electromagnetic characteristics, conduct themselves and make the best response to signals. Different from the traditional external stealth and internal radar wave stealth design, it provides a brand-new idea for the development and design of stealth materials and is an inevitable trend of stealth technology development. Polymer materials have become an important development direction in the field of intelligent stealth because they can be designed at the microscopic level, that is, at the molecular level, and assembled by chemical bonds and hydrogen bonds.
Third, the development prospect of polymer materials
1 high performance
Further improving high temperature resistance, wear resistance, aging resistance, corrosion resistance and high mechanical strength is an important direction for the development of polymer materials, which plays an extremely important role in aviation, aerospace, electronic information technology, automobile industry and household appliances. The development trend of high-performance polymer materials mainly includes creating new polymers, modifying polymers by changing catalysts and catalytic systems, synthesis process, * * poly, * * mixing and crosslinking, changing the aggregated structure of polymers by new processing methods, and modifying polymer materials by micro-compounding.
2. High functionality
Functional polymer materials are the most dynamic new fields in the field of materials. At present, various new functional polymer materials have been developed, such as polymers that can conduct heat and electricity like metals, super absorbent resins that can absorb thousands of times their own weight, and medical polymer materials that can be used as artificial organs. In view of the above development, polymer water-absorbing materials, photoresist materials, polymer separation membranes and polymer catalysts are all research directions of functional polymers.
3 compound
Composite materials can overcome the shortcomings and deficiencies of single materials, give full play to the advantages of different materials, expand the application scope of polymer materials and improve economic benefits. High-performance structural composites are an important direction of new material revolution. At present, it is mainly used in aerospace, shipbuilding and ocean engineering. The future research direction of composite materials mainly includes the research and development of fiber reinforced materials with high performance and high modulus, the synthesis of matrix resin with high strength, excellent processability and excellent heat resistance, the improvement of interface properties and adhesion properties, and the improvement of evaluation technology.
4 intelligence
The intelligentization of polymer materials is a challenging and important subject. Intelligent materials make materials have advanced intelligence possessed by living things, such as foresight, self-diagnosis, self-repair and self-identification, and can give satisfactory answers to environmental changes. Microencapsulated materials that control and regulate drug release according to the state of human body, artificial blood vessels and artificial bones that grow or decompose continuously according to the growth or healing of organisms, and other medical materials. From functional materials to intelligent materials is another leap in materials science, which is the product of the fusion of new materials, molecular and atomic engineering technology, biotechnology and artificial intelligence.
5. Green (surname); green
Although polymer materials have greatly promoted our daily life, we still can't underestimate the pollution caused by polymer materials. Polymer materials that can save energy and resources, emit less waste, pollute the environment, and can be recycled from production to use have attracted great attention, that is, green production of polymer materials is required. There are mainly the following research directions: developing atomic economic polymerization, selecting non-toxic and harmless raw materials, synthesizing polymer materials by using renewable resources, and recycling polymer materials.
Four concluding remarks
Polymer materials have made great contributions to the economic construction of China. China has established a relatively complete research, development and production system of polymer materials. Although China started late in the development and comprehensive utilization of materials, it has made good progress at present. We should improve its overall technical level, devote ourselves to innovating polymerization reactions and methods, and develop a variety of green functional materials and intelligent materials to improve the quality of human life and meet the needs of various industries and new technologies.
References:
[1] Jin Guantai. Theory and application of polymer chemistry, Sinopec Press, 1997.
[2] Ji Caigui et al. Principles and Applications of Polymer Photochemistry, Fudan University Press, No.6, 2003.
Li, Xiang rufu. Principles and technology of polymer synthesis, Science Press, 1999.
Guess you like:
1. Report of National Academic Papers on Polymer Materials
2. National Academic Papers on Polymer Materials
3. National Academic Papers on Polymer Materials
4. Report of National Academic Papers on Polymer Materials
5. Materials science papers