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Polyisocyanurate
Polyisocyanurate (), also referred to as PIR, polyol, or ISO, is a thermoset plastic typically produced as a foam and used as rigid thermal insulation. The starting materials are similar to those used in polyurethane (PUR) except that the proportion of methylene diphenyl diisocyanate (MDI) is higher and a polyester-derived polyol is used in the reaction instead of a polyether polyol. The resulting chemical structure is significantly different, with the isocyanate groups on the MDI trimerising to form isocyanurate groups which the polyols link together, giving a complex polymeric structure. Manufacturing The reaction of (MDI) and polyol takes place at higher temperatures compared with the reaction temperature for the manufacture of PUR. At these elevated temperatures and in the presence of specific catalysts, MDI will first react with itself, producing a stiff, ring molecule, which is a reactive intermediate (a tri-isocyanate isocyanurate compound). Remaining MDI and the tri-i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Building Insulation Materials
Building insulation materials are the building materials that form the thermal envelope of a building or otherwise reduce heat transfer. Insulation may be categorized by its composition (natural or synthetic materials), form (batts, blankets, loose-fill, spray foam, and panels), structural contribution (insulating concrete forms, structured panels, and straw bales), functional mode (conductive, radiative, convective), R-value (insulation), resistance to heat transfer, environmental impacts, and more. Sometimes a thermally reflective surface called a radiant barrier is added to a material to reduce the transfer of heat through radiation as well as conduction. The choice of which material or combination of materials is used depends on a wide variety of factors. Some insulation materials have health risks, some so significant the materials are no longer allowed to be used but remain in use in some older buildings such as asbestos fibers and Urea-formaldehyde#Foam insulation, urea. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PIR Board Fire Test
Pir or PIR may refer to: Places * Pir, Kerman, a village in Kerman Province, Iran * Pir, Satu Mare, commune in Satu Mare County, Romania Religion * Pir (Sufism), a Sufi teacher or spiritual leader * Pir (Zoroastrianism), pilgrimage site in Persia, typically Zoroastrian People * Khan Jahan Lodi, known by the name of Pir Khan was an Afghan noble who rebelled against the Mughal Empire Science and technology * PIR (gene), for a human protein that is a possible transcriptional coregulator * Parrot intermediate representation, one of the two assembly languages for the Parrot virtual machine * Partners in Research, Canadian bio-medical research charity * Passive infrared sensor, detects infrared emission * Peak information rate, a burstable rate set on routers and switches that allow throughput overhead * Polyisocyanurate, a plastic used for thermal insulation * Private information retrieval, a protocol for retrieving data without revealing what was retrieved * Protein Information ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grenfell Tower Fire
On 14 June 2017, a List of fires in high-rise buildings, high-rise fire broke out in the 24-storey Grenfell Tower block of Public housing in the United Kingdom, flats in North Kensington, West London, England, at 00:54 British Summer Time, BST and burned for 60 hours. Seventy people died at the scene and two people died later in hospital, with more than 70 injured and 223 escaping. It was the deadliest structural fire in the United Kingdom since the 1988 Piper Alpha oil-platform disaster and the worst UK residential fire since the Blitz of World War II. The fire was started by an electrical fault in a refrigerator on the fourth floor. As Grenfell was an existing building originally built in concrete to varying tolerances, gaps around window openings following window installation were irregular and these were filled with combustible foam insulation to maintain air-tightness by contractors. This foam insulation around window jambs acted as a conduit into the rainscreen cavity, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PIR Panels 02
Pir or PIR may refer to: Places * Pir, Kerman, a village in Kerman Province, Iran * Pir, Satu Mare, commune in Satu Mare County, Romania Religion * Pir (Sufism), a Sufi teacher or spiritual leader * Pir (Zoroastrianism), pilgrimage site in Persia, typically Zoroastrian People * Khan Jahan Lodi, known by the name of Pir Khan was an Afghan noble who rebelled against the Mughal Empire Science and technology * PIR (gene), for a human protein that is a possible transcriptional coregulator * Parrot intermediate representation, one of the two assembly languages for the Parrot virtual machine * Partners in Research, Canadian bio-medical research charity * Passive infrared sensor, detects infrared emission * Peak information rate, a burstable rate set on routers and switches that allow throughput overhead * Polyisocyanurate, a plastic used for thermal insulation * Private information retrieval, a protocol for retrieving data without revealing what was retrieved * Protein Information ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methylene Diphenyl Diisocyanate
Methylene diphenyl diisocyanate (MDI) is an aromaticity, aromatic diisocyanate. Three isomers are common, varying by the positions of the isocyanate groups around the rings: 2,2′-MDI, 2,4′-MDI, and 4,4′-MDI. The 4,4′ isomer is most widely used, and is also known as 4,4′-diphenylmethane diisocyanate. This isomer is also known as Pure MDI. MDI reacts with polyols in the manufacture of polyurethane. It is the most produced diisocyanate, accounting for 61.3% of the global market in the year 2000. Production Total world production of MDI and polymeric MDI is over 7.5 million tonnes per year (in 2017). As of 2019, the largest producer was Wanhua Chemical Group. Other major producers are Covestro, BASF, Dow Chemical Company, Dow, Huntsman Corporation, Huntsman, Tosoh Corporation, Tosoh, Kumho Mitsui Chemicals. All major producers of MDI are members of the International Isocyanate Institute, whose aim is the promotion of the safe handling of MDI and Toluene diisocyanate, TDI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Building Envelope
A building envelope or building enclosure is the physical separator between the conditioned and unconditioned environment of a building, including the resistance to air, water, heat, light, and noiseSyed, Asif. ''Advanced building technologies for sustainability''. Hoboken, N.J.: John Wiley & Sons, Inc., 2012. 115. Print. transfer. Discussion The building envelope or enclosure is all of the elements of the outer shell that maintain a dry, heated, or cooled indoor environment and facilitate its climate control. Building envelope design is a specialized area of architectural and engineering practice that draws from all areas of building science and indoor climate control. The many functions of the building envelope can be separated into three categories:Straube, J.F., Burnett, E.F.P. ''Building Science for Building Enclosures''. Building Science Press, Westford, 2005. * Support (to resist and transfer structural and dynamic loads) * Control (the flow of matter and energy of all typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyurethanes
Polyurethane (; often abbreviated PUR and PU) is a class of polymers composed of organic chemistry, organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane term does not refer to the single type of polymer but a group of polymers. Unlike polyethylene and polystyrene, polyurethanes can be produced from a wide range of starting materials resulting in various polymers within the same group. This chemical variety produces polyurethanes with different chemical structures leading to many List of polyurethane applications, different applications. These include rigid and flexible foams, and coatings, adhesives, Potting (electronics), electrical potting compounds, and fibers such as spandex and polyurethane laminate (PUL). Foams are the largest application accounting for 67% of all polyurethane produced in 2016. A polyurethane is typically produced by reacting a polymeric isocyanate with a polyol. Since a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plastics
Plastics are a wide range of synthetic or semisynthetic materials composed primarily of polymers. Their defining characteristic, plasticity, allows them to be molded, extruded, or pressed into a diverse range of solid forms. This adaptability, combined with a wide range of other properties such as low weight, durability, flexibility, chemical resistance, low toxicity, and low-cost production, has led to their widespread use around the world. While most plastics are produced from natural gas and petroleum, a growing minority are produced from renewable resources like polylactic acid. Between 1950 and 2017, 9.2 billion metric tons of plastic are estimated to have been made, with more than half of this amount being produced since 2004. In 2023 alone, preliminary figures indicate that over 400 million metric tons of plastic were produced worldwide. If global trends in plastic demand continue, it is projected that annual global plastic production will exceed 1.3 billion tons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TheGuardian
''The Guardian'' is a British daily newspaper. It was founded in Manchester in 1821 as ''The Manchester Guardian'' and changed its name in 1959, followed by a move to London. Along with its sister paper, '' The Guardian Weekly'', ''The Guardian'' is part of the Guardian Media Group, owned by the Scott Trust Limited. The trust was created in 1936 to "secure the financial and editorial independence of ''The Guardian'' in perpetuity and to safeguard the journalistic freedom and liberal values of ''The Guardian'' free from commercial or political interference". The trust was converted into a limited company in 2008, with a constitution written so as to maintain for ''The Guardian'' the same protections as were built into the structure of the Scott Trust by its creators. Profits are reinvested in its journalism rather than distributed to owners or shareholders. It is considered a newspaper of record in the UK. The editor-in-chief Katharine Viner succeeded Alan Rusbridger in 201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Insulation
Thermal insulation is the reduction of heat transfer (i.e., the transfer of thermal energy between objects of differing temperature) between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes and materials. Heat flow is an inevitable consequence of contact between objects of different temperature. Thermal insulation provides a region of insulation in which thermal conduction is reduced, creating a thermal break or thermal barrier, or thermal radiation is reflected rather than absorbed by the lower-temperature body. The insulating capability of a material is measured as the inverse of thermal conductivity, thermal conductivity (k). Low thermal conductivity is equivalent to high insulating capability (R-value (insulation), resistance value). In thermal engineering, other important properties of insulating materials are product density, density (ρ) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint-Gobain
Compagnie de Saint-Gobain S.A. () is a French multinational corporation, founded in 1665 in Paris as the Manufacture royale de glaces de miroirs, and today headquartered on the outskirts of Paris, at La Défense and in Courbevoie. Originally a mirror manufacturer, it also produces a variety of construction, high-performance, and other materials. Saint-Gobain is present in 76 countries and employs more than 170,000 people. History 1665–1789: Manufacture royale Since the mid-17th century, luxury products such as silk textiles, lace, and mirrors were in high demand. In the 1660s, mirrors had become very popular among the upper classes of society: Italian cabinets, châteaux, ornate side tables, and pier-tables were decorated with these expensive and luxurious products. At the time, however, the French were not known for mirror technology; instead, the Republic of Venice was known as the world leader in glass manufacturing, controlling a technical and commercial monopol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Cyanide
Hydrogen cyanide (formerly known as prussic acid) is a chemical compound with the chemical formula, formula HCN and structural formula . It is a highly toxic and flammable liquid that boiling, boils slightly above room temperature, at . HCN is produced on an industrial scale and is a highly valued Precursor (chemistry), precursor to many chemical compounds ranging from polymers to pharmaceuticals. Large-scale applications are for the production of potassium cyanide and adiponitrile, used in mining and plastics, respectively. It is more toxic than solid cyanide compounds due to its Volatility (chemistry), volatile nature. A solution of hydrogen cyanide in water (molecule), water, represented as HCN(aqueous, aq), is called ''hydrocyanic acid''. The Salt (chemistry), salts of the cyanide anion are known as cyanides. Whether hydrogen cyanide is an organic compound or not is a topic of debate among chemists, and opinions vary from author to author. Traditionally, it is considered ino ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
