Polyisocyanurate ( / ˌ p ɒ l ɪ ˌ aɪ s oʊ s aɪ ˈ æ nj ʊər eɪ t / ), 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.
21-751: [REDACTED] Look up pirs in Wiktionary, the free dictionary. PIRs , PIRS , Pirs , or pirs may mean: the plural of pir (disambiguation) or PIR Pirs (ISS module) , a former module of the International Space Station a Russian word, Пирс, meaning " pier " Propulsion Information Retrieval System, part of the Chemical Propulsion Information Analysis Center Police Information Retrieval System, an information system used by
42-565: A core of PIR foam and used extensively as roofing insulation and vertical walls (e.g. for warehousing, factories, office buildings etc.). Other typical uses for PIR foams include industrial and commercial pipe insulation, and carving/machining media (competing with expanded polystyrene and rigid polyurethane foams). Effectiveness of the insulation of a building envelope can be compromised by gaps resulting from shrinkage of individual panels. Manufacturing criteria require that shrinkage be limited to less than 1% (previously 2% ). Even when shrinkage
63-463: A foam and used as rigid thermal insulation. Its thermal conductivity has a typical value of 0.023 W/(m·K) (0.16 BTU·in/(hr·ft ·°F)) depending on the perimeter:area ratio. PIR foam panels laminated with pure embossed aluminium foil are used for fabrication of pre-insulated duct that is used for heating, ventilation and air conditioning systems. Prefabricated PIR sandwich panels are manufactured with corrosion-protected, corrugated steel facings bonded to
84-516: 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 ,
105-468: A mechanical irritant to skin, eyes, and upper respiratory system during fabrication (such as dust). No statistically significant increased risks of respiratory diseases have been found in studies. PIR is at times stated to be fire retardant , or contain fire retardants, but these describe the results of "small scale tests" and "do not reflect [all] hazards under real fire conditions"; the extent of hazards from fire include not just resistance to fire but
126-627: A plastic used for thermal insulation Private information retrieval , a protocol for retrieving data without revealing what was retrieved Protein Information Resource , database and bioinformatics resource Public Interest Registry , manages .org Internet domain Other [ edit ] Pir , a song by Prakash Saput Pacific Imperial Railroad , a defunct railway company in California Performance Index Rating ,
147-729: A statistical formula in basketball Philadelphia International Records , a record company based in Philadelphia, Pennsylvania Philosophy in Review , an academic journal Phoenix International Raceway , Avondale, Arizona Pir of the Britons , king of the Britons Pir Roshan (born 1525), Pashtun warrior-poet and intellectual Pittsburgh Industrial Railroad , reporting mark Portland International Raceway , Portland, Oregon Pre-Islamic recent period , an archaeological assemblage in
168-432: Is a reactive intermediate (a tri-isocyanate isocyanurate compound). Remaining MDI and the tri-isocyanate react with polyol to form a complex poly(urethane-isocyanurate) polymer (hence the use of the abbreviation PUI as an alternative to PIR), which is foamed in the presence of a suitable blowing agent. This isocyanurate polymer has a relatively strong molecular structure, because of the combination of strong chemical bonds ,
189-408: Is different from Wikidata All article disambiguation pages All disambiguation pages Polyisocyanurate 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
210-510: Is limited to substantially less than this limit, the resulting gaps around the perimeter of each panel can reduce insulation effectiveness, especially if the panels are assumed to provide a vapor/infiltration barrier. Multiple layers with staggered joints, ship lapped or tongue & groove joints greatly reduce these problems. Polyisocyanurates of isophorone diisocyanate are also used in the preparation of polyurethane coatings based on acrylic polyols and polyether polyols. PIR insulation can be
231-550: Is recognised as a significant contributor to the fire toxicity of PIR (and PUR) foams. PIR insulation board (cited as the FR4000 and the FR5000 products of Celotex, a Saint-Gobain company) was proposed to be used externally in the refurbishment of Grenfell Tower , London, with vertical and horizontal runs of 100 mm and 150 mm thickness respectively; subsequently "Ipswich firm Celotex confirmed it provided insulation materials for
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#1732852750255252-554: The Royal Canadian Mounted Police Programme d'indicateurs du rendement scolaire du Conseil des ministres de l'Éducation, a program of the Ministry of Education, Recreation and Sports (Quebec) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Pirs . If an internal link led you here, you may wish to change the link to point directly to
273-580: The Persian Gulf Prosopographia Imperii Romani , a collection of Latin inscriptions on notable Romans Parachute Infantry Regiment, airborne infantry unit of the United States Army Pierre Regional Airport , South Dakota, United States (IATA code: PIR) PIR, NYSE symbol for Texas-based retailer Pier 1 Imports See also [ edit ] Pirs (disambiguation) Topics referred to by
294-427: The degree to which toxic products were released, looking at toxicity, time-release profiles, and lethality of doses released, in a range of flaming, non-flaming, and poorly ventilated fires, and concluded that PIR generally released a considerably higher level of toxic products than the other insulating materials studied (PIR > PUR > EPS > PHF; glass and stone wools also studied). In particular, hydrogen cyanide
315-707: The free dictionary. Pir or PIR may refer to: Places [ edit ] Pir, Kerman , a village in Kerman Province, Iran Pir, Satu Mare , commune in Satu Mare County, Romania Religion [ edit ] Pir (Alevism) , one of the 12 ranks of Imam in Alevism Pir (Sufism) , a Sufi teacher or spiritual leader Pir (Zoroastrianism) , pilgrimage site in Persia, typically Zoroastrian Science and technology [ edit ] PIR (gene) , for
336-408: The index increases material stiffness the brittleness also increases, although the correlation is not linear. Depending on the product application greater stiffness, chemical and/or thermal stability may be desirable. As such PIR manufacturers can offer multiple products with identical densities but different indices in an attempt to achieve optimal end use performance. PIR is typically produced as
357-486: The intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Pirs&oldid=1035573021 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Pir (disambiguation) (Redirected from Pir (disambiguation) ) [REDACTED] Look up PIR or pir in Wiktionary,
378-467: The refurbishment." On 14 June 2017 the block of flats, within 15 minutes, was enveloped in flames from the fourth floor to the top 24th floor. The public inquiry into the fire determined that the Celotex cladding material was one of the primary causes of the rapid spread of the fire, as they were much more flammable than permitted by building regulations. Celotex deceived regulators about the fire performance of
399-608: The ring structure of isocyanurate and high cross link density, each contributing to the greater stiffness than found in comparable polyurethanes. The greater bond strength also means these are more difficult to break, and as a result a PIR foam is chemically and thermally more stable: breakdown of isocyanurate bonds is reported to start above 200 °C, compared with urethane at 100 to 110 °C. PIR typically has an MDI/polyol ratio, also called its index (based on isocyanate/polyol stoichiometry to produce urethane alone), higher than 180. By comparison PUR indices are normally around 100. As
420-442: The same term [REDACTED] This disambiguation page lists articles associated with the title Pir . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Pir&oldid=1258159343 " Categories : Disambiguation pages Place name disambiguation pages Hidden categories: Short description
441-483: The scope for toxic byproducts from different fire scenarios. A 2011 study of fire toxicity of insulating materials at the University of Central Lancashire 's Centre for Fire and Hazard Science studied PIR and other commonly used materials under more realistic and wide-ranging conditions representative of a wider range of fire hazard, observing that most fire deaths resulted from toxic product inhalation. The study evaluated
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