A thermoplastic , or plastic thermostatement , is a plastic material, a polymer, which becomes bending or may be formed above a certain temperature and solidified after cooling.
Most thermoplastics have high molecular weight. The polymer chains associate through intermolecular forces, which weaken rapidly with increasing temperature, producing viscous fluid. Thus, thermoplastics can be reconstituted by heating and are typically used to produce parts with various polymer processing techniques such as injection molding, compression molding, calendering, and extrusion. Thermoplastics differ from thermosetting polymers, which form irreversible chemical bonds during the curing process. Thermosets do not melt when heated: they decompose and do not change after cooling.
Above the glass transition temperature and below its melting point, the physical properties of the thermoplastic change drastically without corresponding phase changes. Some thermoplastics do not fully crystallize below glass transition temperatures, retaining some or all of their amorphous characteristics. Amorphous and semi-amorphous plastics are used when high optical clarity is required, since the light is spread strongly by crystallites greater than its wavelength. Amorphous and semi-amorphous plastics are less resistant to chemical attack and crack environmental stresses because they lack a crystal structure.
The fragility can be reduced by the addition of plasticizer, which increases the mobility of the amorphous chain segments to effectively lower the glass transition temperature. Modification of polymers through copolymerization or by addition of non-reactive side chains to the monomers prior to polymerization may also decrease them. Before this technique is used, plastic car parts are often cracked when exposed to cold temperatures. It is a long chain or slightly branched chain molecule capable of repeatedly softening on heating and hardening on cooling.
Video Thermoplastic
Akrilik
Acrylic, a polymer called poly (methyl methacrylate) (PMMA), also known by trade names such as Lucite, Perspex and Plexiglas. It serves as a powerful substitute for glass for items such as aquariums, motorcycle helmets, airplane windows, submarine harbor viewing, and car exterior light lenses. It is extensively used to create signs, including letters and logos. In the medical world, it is used in bone cement and to replace the eyepiece. Acrylic paints consist of suspended PMMA particles in water.
Maps Thermoplastic
ABS
Acrylonitrile butadiene styrene (ABS) is terpolymer synthesized from styrene and acrylonitrile in the presence of polybutadiene. ABS is a lightweight material that exhibits high impact resistance and mechanical toughness. This poses some risk to human health under normal treatment. It is used in many consumer products, such as toys, equipment, and telephones.
Nylon
Nylons belong to a class of polymers called polyamides. It has served as a substitute primarily for hemp, cotton and silk, in products such as parachutes, straps, screens, vests and clothing. Nylon fibers are useful in the manufacture of fabrics, ropes, carpets and musical strings, while in bulk form, nylon is used for mechanical parts including machine screws, gears and electrical tool casing. In addition, it is used in the manufacture of heat resistant composite materials.
PLA
Polylactic acid (polylactide) is a biodegradable thermoplastic aliphatic polyester derived from renewable resources, such as corn starch (in the United States), tapioca root, chips or starch (mostly in Asia), or sugarcane. This is one of the materials used for 3D printing with fused deposition modeling techniques (FDM).
Polybenzimidazole
Polybenzimidazole (PBI, short for Poly- [2,2 '- (m-phenylen) -5,5'-bisbenzimidazole]) fiber is a synthetic fiber with a very high melting point. It has exceptional thermal and chemical stability and is not flammable. It was first discovered by American polymer chemistry, Carl Shipp Marvel, in the pursuit of new materials with superior stability, retention stiffness, toughness at high temperatures. Due to its high stability, Polybenzimidazole is used to make high-performance protective clothing such as fire extinguishers, astronaut space outfits, high-temperature protective gloves, welder apparels and aircraft wall liners. In recent years, polybenzimidazole has found its application as a membrane in a fuel cell.
Polycarbonate
Polycarbonate (PC) thermoplastics ar :) e is known under trademarks such as Lexan, Makrolon, Makroclear, and arcoPlus. They are easy to work, print, and thermoform for many applications, such as electronic components, construction materials, data storage devices, automotive and aircraft components, prosthetics socket checks, and safety glass. Polycarbonate does not have a unique resin identification code. Goods made of polycarbonate may contain the precursors of bisphenol mole A (BPA).
Polyether sulfone
Polyether sulfone (PES) or polysulfone is a specially engineered thermoplastic class with high thermal, oxidative, and hydrolytic stability, and good resistance to aqueous, alkaline, salt, oil and grease mineral acids.
Polyoxymethylene
Polyoxymethylene (POM), also known as acetal, [2] polyacetal and polyformaldehyde, is a thermoplastic technique used in precision parts that require high stiffness, low friction, and excellent dimensional stability. Like many other synthetic polymers, these are produced by different chemical companies with slightly different formulas and are sold under various names like Delrin, Celcon, Ramtal, Duracon, Kepital and Hostaform.
Ketet polyetherher
Polyether ether ketone (PEEK) is a colorless organic thermoplastic polymer in the polyaryletherketone family (PAEK), which is used in engineering applications. Originally introduced by Victrex PLC, then ICI (Imperial Chemical Industries) in the early 1980s. It has attractive properties such as good abrasion resistance, low flammability and emission of toxic fumes and gases.
Polyetherimide
Polyetherimide (PEI), produced by new nitro displacement reactions involving bisphenol A, 4, 4'-methylenedianiline and 3-nitrophthalic anhydride, has high temperature distortion, tensile strength and modulus. They are commonly used in high-performance electrical and electronic components, microwave appliances, and under-marque automotive parts.
Polyethylene
Polyethylene (polyethene, polythene, PE) are families of the same material categorized according to their molecular density and structure. It is also known as poly and is obtained by the addition of ethylene polymerization. This may be low density or high density depending on the process used in the manufacture. It is resistant to moisture and most chemicals. It's flexible at room temperature. (and low temperature) and can be heat sealed. Because it is cheap plastic it is made in large quantities to meet the demand. As an example: Ultra-high-molecular-weight polyethylene (UHMWPE) is strong and resistant to chemicals. It is used to produce mobile machine parts, bearings, gears, artificial joints and some bulletproof vests.
Polyphenylene oxide
Polyphenylene oxide (PPO), obtained from free radicals, polymerization of the growth stage oxidation clutch of 2,6-xylenol, has many attractive properties such as high heat distortion and impact strength, chemical stability against minerals and organic acids, and low water absorption. PPO is difficult to process, and hence commercial resin (Noryl) is made by combining PPO with high-impact polystyrene (HIPS), which serves to reduce the processing temperature.
Polyphenylene sulfide
Polyphenylene sulfide (PPS) is obtained by condensation polymerization of p-dichlorobenzene and sodium sulphide, has excellent chemical resistance, excellent electrical properties, excellent flame retardance, low friction coefficient and high transparency to microwave radiation. PPS is principally used in coating applications. This is done by spraying a porous slurry of PPS particles and heating to temperatures above 370 ° C. PPS specific values ​​may be used in injection molding and compression at temperatures (300 to 370 ° C) in which the PPS particles soften and undergo a real,. The main applications of PPS injection and compression include cookware, bearings, and pumps for service in a variety of corrosive environments.
Polypropylene
Polypropylene (PP) is useful for a wide range of products such as reusable plastic food containers, microwave safe and dishwasher plastic containers, diaper layers, coating and casing, ropes, carpets, plastic molds, piping systems, car batteries, insulation for electric cables and filters for gases and liquids. In the world of medicine, it is used in the treatment of hernia and to make medical equipment is heat resistant. Polypropylene sheets are used for stationery and packaging folders and clear storage areas. Polypropylene is defined by a recyclable plastic number 5. Although relatively inert, it is susceptible to ultraviolet radiation and can greatly decrease in direct sunlight. Polypropylene is not impact resistant like polyethylene (HDPE, LDPE). It is also somewhat permeable to volatile gases and liquids.
Polystyrene
Polystyrene is produced in various forms that have different applications. Extruded polystyrene (PS) is used in the manufacture of disposable cutters, CDs and DVDs, plastic and car boat models, and smoke detector houses. Expanded polystyrene foam (EPS) is used in the manufacture of insulation and packaging materials, such as "nuts" and foams formed to protect fragile products. Polystyrene copolymers are used in the manufacture of toys and casing products.
Polyvinyl chloride
Polyvinyl chloride (PVC) is a hard and lightweight material that is resistant to acids and bases. Mostly used by the construction industry, such as for vinyl wall coverings, sewers, gutters and roofing sheets. It is also converted into a flexible form with the addition of plasticizer, making it useful for items such as hoses, tubes, electrical insulation, coats, jackets and upholstery. Flexible PVC is also used in rubber products, such as water beds and pool toys. PVC is also a common ingredient in vinyl action figures, especially in countries such as Japan, where this material is widely used in so-called Sofubi figures. Because PVC can curl easily and tend to bend in transit, the method to 'fix' this deformation is to heat the plastic until it moves, then 'bend' the material to the correct position.
Teflon
Teflon is a DuPont brand name. The name is applied to a variety of polymers formally known as polytetrafluoroethylene (PTFE), which belongs to the thermoplastic polymer class.
References
External links
- Media related to Thermoplastics on Wikimedia Commons
Source of the article : Wikipedia
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