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Polystyrene
Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is a poor barrier to oxygen and water vapour and has a relatively low melting point. Polystyrene is one of the most widely used plastics, the scale of its production being several million tonnes per year. Polystyrene can be naturally transparent, but can be colored with colorants. Uses include protective packaging (such as packing peanuts and in the jewel cases used for storage of optical discs such as CDs and occasionally DVDs), containers, lids, bottles, trays, tumblers, disposable cutlery, in the making of models, and as an alternative material for phonograph records. As a thermoplastic polymer, polystyrene is in a solid (glassy) state at room temperature but flows if heated above about 100 °C, its glass transition temperature. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foam Peanut
Foam peanuts, also known as foam popcorn, packing peanuts, or packing noodles, are a common loose-fill packaging and cushioning material used to prevent damage to fragile objects during shipping. They are shaped to interlock when compressed and free flow when not compressed. They are roughly the size and shape of an unshelled peanut and commonly made of expanded polystyrene foam. 50–75 millimetres (2-3 in) of peanuts are typically used for cushioning and void filling packaging applications. The original patent was filed for by Robert E. Holden in 1962 and was granted in 1965. Polystyrene foam Polystyrene-based packing peanuts were developed and patented by Tektronix Inc. They were made commercially available circa 1965 by Dow Chemical. Originally made from 100% virgin polystyrene resin, peanuts made from 100% recycled polystyrene have been commercially available since the mid-90s. The color and shape sometimes indicate what it is made of and who made it. Often green is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plastic
Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptability, plus a wide range of other properties, such as being lightweight, durable, flexible, and inexpensive to produce, has led to its widespread use. Plastics typically are made through human industrial systems. Most modern plastics are derived from fossil fuel-based chemicals like natural gas or petroleum; however, recent industrial methods use variants made from renewable materials, such as corn or cotton derivatives. 9.2 billion tonnes of plastic are estimated to have been made between 1950 and 2017. More than half this plastic has been produced since 2004. In 2020, 400 million tonnes of plastic were produced. If global trends on plastic demand continue, it is estimated that by 2050 annual global plastic production will reach over 1, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermoplastic
A thermoplastic, or thermosoft plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. Most thermoplastics have a high molecular weight. The polymer chains associate by intermolecular forces, which weaken rapidly with increased temperature, yielding a viscous liquid. In this state, thermoplastics may be reshaped and are typically used to produce parts by various polymer processing techniques such as injection molding, compression molding, calendering, and extrusion. Thermoplastics differ from thermosetting polymers (or "thermosets"), which form irreversible chemical bonds during the curing process. Thermosets do not melt when heated, but typically decompose and do not reform upon cooling. Above its glass transition temperature and below its melting point, the physical properties of a thermoplastic change drastically without an associated phase change. Some thermoplastics do not fully crystallize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Styrofoam
Styrofoam is a trademarked brand of closed-cell extruded polystyrene foam (XPS), commonly called "Blue Board", manufactured as foam continuous building insulation board used in walls, roofs, and foundations as thermal insulation and water barrier. This material is light blue in color and is owned and manufactured by DuPont DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in .... DuPont also has produced a line of green and white foam shapes for use in crafts and floral arrangements. ''Styrofoam'' is colloquially used worldwide to refer to another material that is usually white in color and made of expanded (not extruded) polystyrene foam ( EPS). It is often used in food containers, coffee cups, and as cushioning material in packaging. The Generic trademark, trademarked term is used g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals. The term "polymer" derives from the Greek word πολύς (''polus'', meaning "many, much") and μέρος (''meros'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass Transition Temperature
The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle "glassy" state into a viscous or rubbery state as the temperature is increased. ISO 11357-2: Plastics – Differential scanning calorimetry – Part 2: Determination of glass transition temperature (1999). An amorphous solid that exhibits a glass transition is called a glass. The reverse transition, achieved by supercooling a viscous liquid into the glass state, is called vitrification. The glass-transition temperature ''T''g of a material characterizes the range of temperatures over which this glass transition occurs (as an experimental definition, typically marked as 100 s of relaxation time). It is always lower than the melting temperature, ''T''m, of the crystalline state of the material, if one exists. Hard plastics like polystyrene and poly(methyl methacrylate) are u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Forming
Vacuum forming is a simplified version of thermoforming, where a sheet of plastic (in various forms HIPS (High impact polystyrene) for low impact products, or for Bathroom shower trays ABS, and exterior vehicle parts HDPE, plus various other types of vacuum formable materials) is heated to a forming temperature, stretched onto a single-surface mould, and forced against the mould by a vacuum. This process can be used to form plastic into permanent objects such as turnpike signs and protective covers. Normally draft angles are present in the design of the mould (a recommended minimum of 3°) to ease removal of the formed plastic part from the mould. Relatively deep parts can be formed if the formable sheet is mechanically or pneumatically stretched prior to bringing it into contact with the mold surface and applying the vacuum. Suitable materials for use in vacuum forming are conventionally thermoplastics. The most common and easiest to use thermoplastic is ''high impact polys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eduard Simon
Johann Eduard Simon (18 September 1789 – 19 June 1856) was an apothecary in Berlin, Germany. Johann Eduard Simon accidentally discovered polystyrene in 1839. Simon distilled an oily substance from storax, the resin of the Sweetgum tree, '' Liquidambar orientalis'', which he named "styrol". Several days later he found that the styrol had thickened, presumably due to polymerisation In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many for ..., into a jelly which he dubbed styrol oxide ("Stryroloxyd").Scheirs, John"Historical Overview of Syrenic Polymers"in References Notes 19th-century German chemists Apothecaries 1789 births 1856 deaths {{Germany-engineer-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Buddle Blyth
John Buddle Blyth (1814 – 24 December 1871) was a Jamaican-born chemist who was the first professor of chemistry at Queen's College Cork in Ireland. With August Wilhelm von Hofmann, he was the first to report photopolymerisation which they observed when styrene became metastyrol after exposure to sunlight. Early life and family John Blyth was born in Jamaica in 1814 to John Blythe and Mary Buddle, a "free woman of colour". He was baptised at Mesopotamia in Westmoreland Parish on 11 April 1816 by Edmund Pope, rector of Westmorland, and described as a "free child of colour".John Buddle Blyth Jamaica, Church of England Parish Register Transcripts, 1664-1880. Family Search. Retrieved 12 January 2019. He had brothers Charles (181 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apothecary
''Apothecary'' () is a mostly archaic term for a medical professional who formulates and dispenses '' materia medica'' (medicine) to physicians, surgeons, and patients. The modern chemist (British English) or pharmacist (British and North American English) now perform this role. In some languages and regions, the word "apothecary" is still used to refer to a retail pharmacy or a pharmacist who owns one. Apothecaries' investigation of herbal and chemical ingredients was a precursor to the modern sciences of chemistry and pharmacology. In addition to dispensing herbs and medicine, apothecaries offered general medical advice and a range of services that are now performed by other specialist practitioners, such as surgeons and obstetricians. Apothecary shops sold ingredients and the medicines they prepared wholesale to other medical practitioners, as well as dispensing them to patients. In 17th-century England, they also controlled the trade in tobacco which was imported as a me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storax
Storax ( la, storax; el, στύραξ, ''stúrax''), often commercially sold as styrax, is a natural resin isolated from the wounded bark of ''Liquidambar orientalis'' Mill. (Asia Minor) and ''Liquidambar styraciflua'' L. (Central America) (Hamamelidaceae). It is distinct from benzoin (also called "storax"), a similar resin obtained from the Styracaceae plant family. Composition Purified storax contains circa 33 to 50% storesin, an alcoholic resin, both free and as cinnamic esters. Contains 5 to 15% cinnamic acid, 5 to 15% cinnamyl cinnamate, circa 10% phenylpropyl cinnamate; small amounts of ethyl cinnamate, benzyl cinnamate, and styrene, Some may contain traces of vanillin. Some sources report a resin containing triterpenic acids ( oleanolic and 3-epioleanolic acids). Uses Storax has a pleasant, floral/lilac, leathery, balsamic smell. Storax and its derivatives ( resinoid, essential oil, absolute) are used as flavors, fragrances, and in pharmaceuticals (Friar's Balsam). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquidambar Orientalis
''Liquidambar Orientalis'', commonly known as oriental sweetgum or Turkish sweetgum, is a deciduous tree in the genus ''Liquidambar'', native to the eastern Mediterranean region, that occurs as pure stands mainly in the floodplains of southwestern Turkey and on the Greek island of Rhodes. Description Oriental sweet gum is a deciduous tree, in height with a trunk of in diameter. The unisexual flowers bloom from March to April. The fruits ripen in November to December and the seeds are wind dispersed. The tree is very attractive and especially valued for its colourful autumn leaves. Oriental sweet gum trees favour an elevation of between , a mean annual rainfall of and a mean annual temperature of . The tree's optimal growth is on rich, deep and moist soils such as bogs, river banks and coastal areas but it is also able to grow on slopes and dry soil. Biotope The forests of this Tertiary relict endemic taxon are found notably within a specially protected area between Dalyan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
