Materyèl polymère: materyèl makromolekilè, yon materyèl ki baze sou konpoze polymère. Materyèl polymère yo se materyèl ki konpoze de konpoze ki gen pwa molekilè relativman wo, ki gen ladan kawotchou, plastik, fib, kouch, adezif ak polymère -materyèl konpoze. Polymères se fòm lavi. Tout bèt vivan yo ka wè kòm yon koleksyon makromolekil.
Klasifikasyon nan plastik
1. Klasifikasyon selon karakteristik itilizasyon yo
According to the different use characteristics of famous plastics, plastics are usually divided into three types: general plastics, engineering plastics and special plastics. ①General plastics generally refer to plastics with large output, wide application, good formability and low price. There are five general types of plastics, namely polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS) and acrylonitrile-butadiene-styrene copolymer (ABS). They are all thermoplastics. ②Engineering plastics generally refer to plastics that can withstand a certain external force, have good mechanical properties, high and low temperature resistance, and good dimensional stability, and can be used as engineering structures, such as polyamide, polysulfone, etc. Engineering plastics are divided into two categories: general engineering plastics and special engineering plastics. General engineering plastics include: polyamide, polyoxymethylene, polycarbonate, modified polyphenylene ether, thermoplastic polyester, ultra-high molecular weight polyethylene, methyl pentene polymer, vinyl alcohol copolymer, etc. Special engineering plastics are divided into cross-linked and non-cross-linked types. Cross-linked types include: polyaminobismaleamide, polytriazine, cross-linked polyimide, heat-resistant epoxy resin, etc. Non-crosslinked types include: polysulfone, polyethersulfone, polyphenylene sulfide, polyimide, polyetheretherketone (PEEK), etc. ③Special plastics generally refer to special functions that can be used for special applications such as aviation and aerospace field of plastic. For example, fluoroplastics and silicones have special functions such as outstanding high temperature resistance and self-lubrication. Reinforced plastics and foamed plastics have special properties such as high strength and high cushioning. These plastics belong to the category of special plastics. a. Strong plastics: Reinforced plastic raw materials can be divided into granular (such as calcium-plastic reinforced plastics), fibrous (such as glass fiber or glass cloth reinforced plastics), and flakes (such as mica reinforced plastics). According to the material, it can be divided into three types: cloth-based reinforced plastics (such as rags reinforced or asbestos reinforced plastics), inorganic mineral-filled plastics (such as quartz or mica-filled plastics), and fiber-reinforced plastics (such as carbon fiber reinforced plastics). b. Foam: Foam can be divided into rigid, semi-rigid and flexible foam. Rigid foam plastic has no flexibility, and the compression hardness is very large. Only when a certain stress value is reached, deformation occurs, and it cannot be restored to its original state after the stress is relieved. Return to the original state, and the residual deformation is small; the flexibility and other properties of semi-rigid foam are between rigid and flexible foam.
2. Klasifikasyon selon pwopriyete fizik ak chimik
According to the different physical and chemical properties of various plastics, plastics can be divided into two types: thermosetting plastics and thermoplastic plastics. (1) Thermoplastics Thermoplastics: refers to plastics that melt after heating, can flow until the mold is cooled, and then melt after heating; heating and cooling can be used to produce reversible changes ( Liquid ←→ Solid), is the so-called physical change. The continuous use temperature of general thermoplastics is below 100 degree C, and polyethylene, polyvinyl chloride, polypropylene, and polystyrene are called the four general plastics. Thermoplastics are divided into hydrocarbons, vinyls with polar genes, engineering, cellulose and other types. Soft when heated, hard when cooled, can repeatedly soften and harden and maintain a certain shape. It is soluble in certain solvents and has the property of being soluble and soluble. Thermoplastics have excellent electrical insulation properties, especially polytetrafluoroethylene (PTFE), polystyrene (PS), polyethylene (PE), and polypropylene (PP) all have extremely low dielectric constant and dielectric loss. For high frequency and high voltage insulating material. Thermoplastics are easy to form and process, but have low heat resistance and are prone to creep. The degree of creep varies with the load, ambient temperature, solvent, and humidity. In order to overcome these weaknesses of thermoplastics and meet the needs of applications in space technology, new energy development and other fields, countries are developing heat-resistant resins that can be melt-molded, such as polyetheretherketone (PEEK), polyethersulfone (PES) , polyarylsulfone (PASU), polyphenylene sulfide (PPS), etc. Composite materials using them as matrix resins have higher mechanical properties and chemical resistance, can be thermoformed and welded, and have better interlaminar shear strength than epoxy resins. For example, using polyether ether ketone as matrix resin and carbon fiber to make composite material, the fatigue resistance exceeds that of epoxy/carbon fiber. It has good impact resistance, good creep resistance at room temperature, good processability, and can be used continuously at 240 to 270 degree C. It is a very ideal high temperature resistant insulating material. The composite material made of polyethersulfone as the matrix resin and carbon fiber has high strength and hardness at 200 degree C, and can maintain good impact resistance at -100 degree C; non-toxic, non-flammable, minimal smoke, radiation resistance Well, it is expected to be used as a key component of spacecraft, and can also be molded into radomes and so on. Formaldehyde cross-linked plastics include phenolic plastics, amino plastics (such as urea-formaldehyde-melamine-formaldehyde, etc.). Other cross-linked plastics of plastic film include unsaturated polyester, epoxy resin, phthalate resin, etc. (2) Thermosetting plastics Thermosetting plastics refer to plastics that can be cured or have insoluble (melting) properties under heat or other conditions, such as phenolic plastics, epoxy plastics, etc. Thermosetting plastics are divided into two types: formaldehyde cross-linked and other cross-linked. After thermal processing, an insoluble and insoluble cured product is formed, and its resin molecules are cross-linked into a network structure from a linear structure. Further heat will decompose and destroy. Typical thermosetting plastics include phenolic, epoxy, amino, unsaturated polyester, furan, polysiloxane and other materials, as well as newer poly(diacrylate) plastics. They have the advantages of high heat resistance and not easy to deform when heated. The disadvantage is that the mechanical strength is generally not high, but the mechanical strength can be improved by adding fillers to make laminates or molded materials. Thermosetting plastics made of phenolic resin as the main raw material, such as phenolic molded plastics (commonly known as bakelite), are durable, dimensionally stable, and resistant to other chemical substances except strong alkalis. Various fillers and additives can be added according to different uses and requirements. For varieties requiring high insulation performance, mica or glass fiber can be used as filler; for heat-resistant varieties, asbestos or other heat-resistant fillers can be used; for shock-resistant varieties, various appropriate fibers or rubber can be used as fillers And some toughening agents to make high toughness materials. In addition, phenolic resins modified by aniline, epoxy, polyvinyl chloride, polyamide, polyvinyl acetal, etc. can also be used to meet the requirements of different uses. Phenolic resin can also be used to make phenolic laminate, which is characterized by high mechanical strength, good electrical properties, corrosion resistance, easy processing, and is widely used in low-voltage electrical equipment. Aminoplastics include urea formaldehyde, melamine formaldehyde, urea melamine formaldehyde, etc. They have the advantages of hard texture, scratch resistance, colorless, translucent, etc. Adding pigments can make colorful products, commonly known as electric jade. Because it is oil-resistant and not affected by weak alkalis and organic solvents (but not acid-resistant), it can be used for a long time at 70 degree , and can withstand 110 to 120 degree in a short time, and can be used in electrical products. Melamine formaldehyde plastic has higher hardness than urea formaldehyde plastic, and has better water resistance, heat resistance and arc resistance, and can be used as arc-resistant insulating material. There are many kinds of thermosetting plastics made of epoxy resin as the main raw material, of which about 90 percent are based on bisphenol A epoxy resin. It has excellent adhesion, electrical insulation, heat resistance and chemical stability, small shrinkage and water absorption, and good mechanical strength. Both unsaturated polyester and epoxy resin can be made into FRP with excellent mechanical strength. Such as unsaturated polyester FRP, it has good mechanical properties and low density (only 1/5 to 1/4 of steel, 1/2 of aluminum), and is easy to process into various electrical parts. The electrical and mechanical properties of plastics made of dipropylene phthalate resin are superior to those of phenolic and amino thermosets. It has low hygroscopicity, stable product size, good molding performance, acid and alkali resistance, boiling water and some organic solvents. Molding compounds are suitable for the manufacture of parts with complex structures, both temperature resistance and high insulation. Generally, it can be used for a long time in the temperature range of -60 to 180 degree , and the heat resistance level can reach F grade to H grade, which is higher than the heat resistance of phenolic and aminoplast. Silicone plastics in the form of polysilicon ether structures are widely used in electronics and electrical technology. Silicone laminated plastics are mostly reinforced with glass cloth; silicone molded plastics are mostly filled with glass fiber and asbestos, which are used to manufacture parts of high temperature, high frequency or submersible motors, electrical appliances, and electronic equipment. This type of plastic is characterized by a small dielectric constant and tgδ value, and is less affected by frequency. It is used for corona and arc resistance in the electrical and electronic industries. Even if the discharge causes decomposition, the product is silicon dioxide instead of conductive carbon black. . These materials have outstanding heat resistance and can be used continuously at 250 degree . The main disadvantages of polysiloxane are low mechanical strength, low adhesiveness and poor oil resistance. Many modified organosilicon polymers have been developed, such as polyester-modified organosilicon plastics, which are used in electrical technology. Some plastics are both thermoplastic and thermosetting plastics. For example, polyvinyl chloride is generally a thermoplastic. Japan has developed a new type of liquid polyvinyl chloride that is thermosetting and has a molding temperature of 60 to 140 degree C; a plastic called Lendex in the United States has both thermoplastic processing. Features, but also the physical properties of thermosetting plastics. ①Hydrocarbon plastics. It is a non-polar plastic with crystalline and non-crystalline properties. Crystalline hydrocarbon plastics include polyethylene, polypropylene, etc., and non-crystalline hydrocarbon plastics include polystyrene. ②Vinyl plastics containing polar genes. Except for fluoroplastics, most of them are amorphous transparent bodies, including polyvinyl chloride, polytetrafluoroethylene, polyvinyl acetate, etc. Most vinyl monomers can be polymerized using free-radical catalysts. ③ thermoplastic engineering plastics. Mainly include polyoxymethylene, polyamide, polycarbonate, ABS, polyphenylene ether, polyethylene terephthalate, polysulfone, polyethersulfone, polyimide, polyphenylene sulfide, etc. Teflon. Modified polypropylene and the like are also included in this range. ④ Thermoplastic cellulose plastics. Mainly include cellulose acetate, cellulose acetate butyrate, celluloid, cellophane, etc. 3. Classification by processing method According to different molding methods of various plastics, it can be divided into various types such as film pressing, lamination, injection, extrusion, blow molding, casting plastic and reaction injection plastic. Film-pressed plastics are mostly plastics whose physical properties are similar to those of general solid plastics; laminated plastics refer to fiber fabrics impregnated with resin, which are combined into a whole material by lamination and hot pressing; injection, extrusion and blowing Plastics are mostly plastics with similar physical properties and processing properties to general thermoplastics; cast plastics refer to liquid resin mixtures that can be poured into a mold and hardened into a certain shape product under no pressure or a little pressure, such as MC Nylon, etc.; Reaction injection plastic is a plastic that uses liquid raw materials, pressurized and injected into the film cavity to make it react and solidify into a certain shape product, such as polyurethane.
