Chinese name: polymer material mbth: polymer material classification, polymer material classification by source, polymer material classification by application, polymer material classification by application function, polymer main chain structure classification, other classification, characteristics, name and use, plastic, rubber, fiber, coating, adhesive, new polymer material, polymer separation membrane, polymer magnetic material, optical functional polymer material, polymer composite material, synthetic processing, and polymer material classification by. Polymer materials are divided into natural polymer materials and synthetic polymer materials according to their sources. Natural polymers are macromolecular substances existing in animals, plants and organisms, which can be divided into natural fibers, natural resins, natural rubber and animal glue. Synthetic polymer materials mainly refer to plastics, synthetic rubber and synthetic fibers, in addition to adhesives, coatings and various functional polymer materials. Synthetic polymer materials have properties that natural polymer materials do not have or are superior-lower density, higher mechanics, wear resistance, corrosion resistance, electrical insulation and so on. Polymer materials are classified according to the application. Polymer materials are divided into rubber, fiber, plastic, polymer adhesive, polymer coating and polymer-based composite materials according to their characteristics. ① Rubber is a linear flexible polymer. The valence between molecular chains is small, and molecular chains are flexible. Under the action of external force, great deformation can occur, and it can be restored to its original state quickly after removing external force. There are two kinds of natural rubber and synthetic rubber. ② Fibers are divided into natural fibers and chemical fibers. The former refers to silk, cotton, hemp, wool and so on. The latter is made of natural polymer or synthetic polymer through spinning and post-treatment. Fiber has high valence, low deformability and high modulus, and is generally a crystalline polymer. ③ Plastic is made of synthetic resin or chemically modified natural polymer as the main component, and then additives such as fillers and plasticizers are added. Its intermolecular valence, modulus and deformation are between rubber and fiber. Generally, synthetic resins are divided into thermosetting plastics and thermoplastic plastics according to their characteristics; According to the purpose, it is divided into general plastics and engineering plastics. ④ Polymer adhesive is an adhesive material with synthetic natural polymer compounds as the main component. There are two kinds of natural and synthetic adhesives. Synthetic adhesives are widely used. ⑤ Polymer coating is made of polymer as the main film-forming substance, adding solvents and various additives. According to the different film-forming substances, it can be divided into grease coatings, natural resin coatings and synthetic resin coatings. ⑥ Polymer-based composite material is a composite material based on polymer compounds and added with various reinforcing materials. It combines the performance characteristics of the original materials and can be designed as required. Polymer composites, also known as polymer modification, can be divided into molecular modification and * * * mixed modification. ⑦ Functional polymer materials. Functional polymer materials not only have the general mechanical properties, insulating properties and thermal properties of polymers, but also have special functions such as material, energy and information conversion, magnetism, transmission and storage. Polymer information conversion materials, polymer transparent materials, polymer mimetic enzymes, biodegradable polymer materials, polymer shape memory materials and medical and medical polymer materials have been applied. Polymers can be divided into the above categories according to their mechanical properties and service conditions. However, there is no strict boundary between various polymers. The same polymer can be made into plastic or fiber, such as nylon, through different synthetic methods and molding processes. High polymers such as polyurethane have both glassy properties and good elasticity at room temperature, so it is hard to say whether they are rubber or plastic. Polymer materials are classified according to their application functions. Polymer materials are divided into three categories: general polymer materials, special polymer materials and functional polymer materials. General polymer materials refer to polymer materials that can be produced on a large scale and have been widely used in the main fields of national economy such as construction, transportation, agriculture, electrical and electronic industry and people's daily life. Among them, it is divided into plastic, rubber, fiber, adhesive, paint and other different types. Special polymer materials are mainly a kind of polymer materials with excellent mechanical strength and heat resistance, such as polycarbonate, polyimide and other materials, which have been widely used in engineering materials. Functional polymer materials refer to polymer compounds that have specific functions and can be used as functional materials, including functional separation membranes, conductive materials, medical polymer materials, liquid crystal polymer materials and so on. Classification according to polymer backbone structure ① carbon chain polymer: molecular backbone is composed of C atoms, such as PP, PE, PVC ② heterochain polymer: molecular backbone is composed of C, O, N, P and other atoms. Such as: polyamide, polyester, silicone oil (3) element organic polymer: the molecular main chain does not contain C atoms, but only consists of some heteroatoms. For example, other types of silicone rubber are classified according to the geometry of polymer backbone: linear polymer, branched polymer and bulk polymer. According to the microscopic arrangement of polymers, they can be divided into crystalline polymers, semi-crystalline polymers and amorphous polymers. It is characterized by large molecular weight (generally above 10000) and polydisperse molecular weight distribution. That is, polymer compounds are different from small molecules and become a mixture of many polymers with different molecular weights after polymerization. The molecular weight of the polymer we are talking about is actually the average molecular weight. Of course, the calculated average molecular weight is also divided into number average molecular weight, viscosity-average molecular weight, weight average molecular weight and so on. Small molecules have a fixed molecular weight, and they are all composed of molecules with a certain molecular weight. This is the characteristic difference between polymers and small molecules. Name and Usage Plastic refers to a material with polymer as the main component that can be molded into a certain shape under certain conditions (temperature, pressure, etc.). ) and keep its shape unchanged at room temperature. Plastics can be divided into thermoplastics and thermosetting plastics according to the conditions after heating. After heating, it softens, and the plastic that forms polymer melt becomes thermoplastic. The main thermoplastics are polyethylene, polypropylene, polystyrene, polymethylmethacrylate, polyvinyl chloride, nylon, polycarbonate, polyurethane, polytetrafluoroethylene, polyethylene terephthalate and so on. Plastics that cure after heating and form cross-linked insoluble structures are called thermosetting plastics. Common are epoxy resin, phenolic plastic, polyimide, melamine formaldehyde resin and so on. The processing methods of plastics include injection, extrusion, film pressing, hot pressing and blow molding. Rubber rubber can be divided into natural rubber and synthetic rubber. The main component of natural rubber is polyisoprene. The main varieties of synthetic rubber are butyl rubber, cis-butadiene rubber, chloroprene rubber, EPDM rubber, acrylate rubber, polyurethane rubber, silicone rubber and fluororubber. Fiber fiber is another important application of polymer materials. Common synthetic fibers are nylon, polyester, acrylic polyester fiber, aramid fiber and polypropylene fiber. Paint coating is a layer of polymer material coated on the surface of industrial or daily products to play an aesthetic or protective role. Commonly used industrial coatings are epoxy resin and polyurethane. Polymeric adhesive adhesive is another important polymer material. Humans began to use natural polymer materials such as starch and gum as adhesives a long time ago. Modern adhesives can be divided into polymeric types according to their usage methods, such as epoxy resin; Hot melt type, such as nylon and polyethylene; Pressure type, such as natural rubber; Water-soluble, such as starch. New polymer materials Polymer materials include plastics, rubber, fibers, films, adhesives and coatings. Among them, plastics, synthetic fibers and synthetic rubber, which are called the three major synthetic materials of modern polymers, have become indispensable and important materials for national economic construction and people's daily life. Although polymer materials have developed rapidly because of many irreplaceable advantages of metal and inorganic materials, so-called general polymers that can only be used under ordinary conditions have been produced on a large scale, and they have shortcomings such as poor mechanical strength and rigidity and low heat resistance. The development of modern engineering technology puts forward higher requirements for polymer materials, thus promoting the development of polymer materials in the direction of high performance, functionalization and biochemistry, and thus many new polymer materials with low output, high price and excellent performance have emerged. Polymer separation membrane Polymer separation membrane is a semi-permeable membrane made of polymer materials with selective permeability. Using this semi-permeable membrane, driven by pressure difference, temperature gradient, concentration gradient or potential difference, the separation technology of gas mixture, liquid mixture or solution of organic and inorganic substances is more energy-saving, efficient and clean, so it is considered as an important technology to support the new technological revolution. The membrane separation process mainly includes reverse osmosis, ultrafiltration, microfiltration, electrodialysis, pressure dialysis, gas separation, pervaporation and liquid membrane separation. Used for preparation separation, pervaporation and liquid membrane separation. There are many kinds of polymer materials used to prepare separation membranes. At present, maple, polyolefin, cellulose lipid and silicone are widely used. There are also many forms of membrane, generally using flat membrane and overhead fiber. Popularization and application of polymer separation membrane can obtain great economic and social benefits. For example, salt production by ion exchange membrane electrolysis can reduce pollution and save energy: seawater desalination and reverse osmosis desalination consume less energy than other methods; Enriching oxygen from air by gas separation membrane can greatly improve the oxygen recovery rate. Polymer magnetic material Polymer magnetic material is one of the materials that give new meaning and content to the traditional application of magnetism and polymer (synthetic resin, rubber) while constantly exploring new application fields of magnetism and polymer. The early magnetic materials originated from natural magnets, and then were sintered or cast into magnetic bodies by magnetite (ferrite). At present, there are three kinds of magnetic materials commonly used in industry, namely ferrite magnet, rare earth magnet and Al-Ni-Co alloy magnet. Their disadvantages are hard and brittle, and poor processability. In order to overcome these defects, polymer magnetic materials made by mixing magnetic powder with plastic or rubber came into being. The composite polymer magnetic material made by this method has attracted more and more attention because of its light specific gravity, easy processing into products with high dimensional accuracy and complex shape, and integrated molding with other components. Polymer materials Polymer magnetic materials can be mainly divided into two categories, namely structural type and composite type. The so-called structural type refers to a magnet made of polymer without adding inorganic magnetic powder. At present, the main practical value is compounding. Optical functional polymer material The so-called optical functional polymer material refers to a polymer material that can transmit, absorb, store and convert light. At present, there are many such materials, mainly including light guide materials, optical recording materials, optical processing materials and optical plastics (such as plastic lenses and contact lenses). ), optical conversion system materials, optical display materials, light guide materials, photosynthetic materials, etc. Optical functional polymer materials can be made into a wide variety of linear optical materials through the transmission of light in the whole society, such as ordinary safety glass, various lenses, prisms and so on. Using the curve propagation characteristics of polymer materials, nonlinear optical elements such as plastic optical fiber and plastic time-sensitive composite optical fiber can be developed. The basic materials of advanced information storage elements are high-performance plexiglass and polycarbonate. In addition, using the photochemical reaction of polymer materials, photosensitive resins, photocurable coatings and adhesives widely used in electronic industry and printing industry can be developed. Using the energy conversion characteristics of polymer materials, light guiding materials and photochromic materials can be made; Based on the characteristic that the refractive index of some polymer materials changes with mechanical stress, photoelastic materials can be developed to study the stress distribution in force structure materials. Polymer composites are multiphase materials composed of polymer materials and other substances with different compositions, shapes and properties. The biggest advantage of polymer composites is that they have the advantages of various materials, such as high strength, light weight, temperature resistance, corrosion resistance, heat insulation and insulation. According to the application purpose, polymer materials and other materials with special properties are selected to make composite materials that meet the needs. Polymer composites can be divided into two categories: polymer structural composites and polymer functional composites. The former is dominant. Polymer structure composites include two components: ① reinforcing agent. It is a kind of fiber and fabric with high strength, high modulus and temperature resistance, such as glass fiber, silicon nitride whisker, boron fiber and above. ② Matrix materials. Mainly adhesives, such as thermosetting resins such as unsaturated polyester resin, epoxy resin, phenolic resin and polyimide, and thermoplastic resins such as styrene and polypropylene. The specific strength and modulus of this composite material are higher than that of metal, and it is an indispensable material in national defense and cutting-edge technology. Synthetic polymer materials should be synthesized before processing, and monomer synthetic polymers should be granulated before melting processing. The synthesis methods of polymer materials include bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization and gas phase polymerization. Among them, initiator plays an important role. Azo initiator and peroxide initiator are both commonly used initiators, and polymer additives often have obvious effects on improving the properties of polymer materials and reducing costs. Processing technology The processing and molding of polymer materials is not a simple physical process, but an important link that determines the final structure and properties of polymer materials. Except that adhesives and coatings can be used directly without processing and molding, rubber, fiber and plastic usually need to be processed into products through corresponding molding methods. The common molding methods of general plastic products are extrusion, injection, calendering, blow molding, compression molding or transfer molding. Rubber products have molding processes such as plasticization, mixing, calendering or extrusion. Fibers include spinning solution preparation, fiber forming and winding, post-treatment, as-spun fiber stretching and heat setting. In the process of polymer molding, it may be affected by the changes of temperature, pressure, stress and action time, which will lead to chemical reactions such as polymer degradation and crosslinking, and change the aggregate structure and chemical structure of polymer. Therefore, the processing technology not only determines the appearance and quality of polymer products, but also has an important influence on the supramolecular structure, texture structure and even chain structure of materials.