polybutene structural formula

Restricted: EWG VERIFIED products cannot contain this ingredient without adequate substantiation. The randomness of these components along the chain make two polybutene molecules difficult to pack together nicely, thus lowering the melting point of the compound. Polybutene only exists as a refined product. Polybutene - Risk and Safety. Polyisobutene, also reffered to as Polyisobutylene, (PIB) has been a core business of BASF for more than 85 years. It is calculated using a weight-of-evidence . Incompatible with strong oxidizing agents. WGK Germany: 3: Polybutene structural formula click to enlarge the image View History Polybutene. Butene: Butene is an alkene. [3] It shows lower resistance to aromatic and chlorinated hydrocarbons as well as oxidising acids than other polymers such as polysulfone and polyamide 6/6. At room temperature, it spontaneously converts into the form-I with the melting point of 135C and density of 0.95 g/cm3.[1]. The rats were monitored for their body weights, mortality and reactions, tumor incidence, and hematologic, urologic, and pathologic changes. National Library of Medicine. The relative density (d415) was 0.8~0.9. Trust is the basis of every partnership. mixed with the same amount of polyvinyl acetate and chewed for 15min, polybutene did not transfer to saliva. [3][8], Isotactic polybutylene crystallizes in three different forms. Polybutene is safe to use, because it is non-toxic. such as a virus or attack. By: Mohamed Adel Mohamadein The goal was to compare the biological response of the corneal stroma with three porous materials: a melt blown microfibre web of polybutylene:polypropylene (80:20); a polyester spun laced fabric (pol Biomacromolecules 6(6) , 3474-80, (2005). Here you can find out more about the polybutenes supplied by TER Chemicals, their applications, their chemical properties and the benefits they bring to industrial production. The large non-polar surface area created by these long carbon chains and ease of mixing being a liquid give polybutene its sought after adhesive properties. Modify Date. wg&/7~O3&Zc, _|5D+wzyLw \UEz'# r{pt"|I0>i`%$R mi./y@pi(>OsUbqvH '2e)y(2ms"#2mMfeUJX [2] Compared to PET (polyethylene terephthalate), PBT has slightly lower strength and rigidity, slightly better impact resistance, and a slightly lower glass transition temperature. endstream endobj startxref naphtha obtained from petroleum is cracked and fractionated to obtain a mixed gas of butene and butane, which is polymerized at a temperature of -30~30 with lead chloride and Fred a gram of Ford catalyst (Friedel-Crafts catalyst). Polybutene is a light colored, nondrying, sticky liquid. contact Polybutene undergoes thermoplastic processes such as injection molding or extrusion at temperatures above 190C. Further, recent studies have shown that PBT has superior UV properties to PET based fabrics such as T400.[6]. Kuwait, the United Kingdom, Korea and Spain, PB-1 piping systems have a strong position.[8]. return. Chemically these are hydrogenated homopolymers of 1-Decene and are categorized as Group IV base oils. 9003-28-5 Chemical Name: Polybutene CBNumber: CB0316097 Molecular Formula: C4H8 Molecular Weight: 56.10632 MDL Number: MFCD00084367 MOL File: 9003-28-5.mol Request For Quotation Polybutene Properties SAFETY WGK Germany 3 Polybutene Chemical Properties,Uses,Production Chemical Properties gum base. In the industry, they are especially valued for their low creep, low susceptibility to stress cracks and high heat resistance. >> amp version: Polybutenes [2] Production [ edit] Polybutylene is produced by polymerisation of 1-butene using supported Ziegler-Natta catalysts . Vapor may act as a simple asphyxiant in high concentrations; General Treatment for Exposure: INHALATION: remove victim from exposure; Toxicity by Inhalation (Threshold Limit Value): Data not available; Short-Term Inhalation Limits: Data not available; Toxicity by Ingestion: Grade 0, LD50 > 15 g/kg; Late Toxicity: None; Vapor (Gas) Irritant Characteristics: Vapors are nonirritating to the eyes and throat; Liquid or Solid Irritant Characteristics: No appreciable hazard. %PDF-1.6 % Polybutylene exhibits high tear, impact, and puncture resistance. Chemical Name: POLYBUTENES CBNumber: CB3413708 Molecular Formula: C8H16 Molecular Weight: 112.21264 MDL Number: MFCD00197897 MOL File: 9003-29-6.mol MSDS File: SDS Modify Date: 2022-12-21 16:56:50 Request For Quotation POLYBUTENES Properties SAFETY POLYBUTENES price More Price (4) POLYBUTENES Chemical Properties,Uses,Production Chemical Properties average Mn ~2,300 by VPO, isobutylene >90 %, Polybutenes Tianjin heowns Biochemical Technology Co., Ltd. Chizhou Kailong Import and Export Trade Co., Ltd. TRIS(2,2,6,6-TETRAMETHYL-3,5-HEPTANEDIONATO)DYSPROSIUM(III), TRIS(2,2,6,6-TETRAMETHYL-3,5-HEPTANEDIONATO)EUROPIUM(III), 1,2-Ethanediamine, reaction products with chlorinated isobutylene homopolymer, Polybutenes Polybutene is a polymer of one or more butylenes obtained from petroleum oils. away script or learning how to better use E-utilities, It is used to make up for the shortcomings of polyvinyl acetate hardening when cold and the population being too soft after saliva. This website uses cookies. Polybutenes are liquid, transparent and colorless polymers synthesized from C4. Y m N >C;f( 5 Feel free to get in touch with us. COPYRIGHT TER Chemicals GmbH & Co. KG2023, TER Chemicals GmbH & Co. KG Belongs to the Following Reactive Group (s) Hydrocarbons, Aliphatic Unsaturated Potentially Incompatible Absorbents Home (current) Spectral . 1) Two different spatial arrangements of methyl groups about a double bond in 2-butene give rise to the following geometrical isomers. Due to its high molecular weight, polybutene does not tend to crack when subject to stress and therefore gives the elastic raw material a high level of flexibility. It is used to make up for the shortcomings of polyvinyl acetate hardening when cold, and the population is too soft after saliva, and the amount of polyvinyl acetate accounts.Buy Polybutenes.Molecular Fomula:C8H16,Molar Mass:112.21264,Density:0.908g/mLat 25C,Melting Point:94.3-104.8 C,Boling Point:293-341 C,Flashing Point:>230F,Vapor Presure . PB-1 is a high molecular weight, linear, isotactic, and semi-crystalline polymer. Showing 1-1 of 1 result for " polybutene " within Products. FORMULA [CH2CH(C2H5)]n . 2,5-Furandione, dihydro-, polybutenyl derivs., reaction products with tetraethylenepentamine, Calcium, nonylphenol sulfides phosphosulfurized polybutene complexes. The differences depend on viscosity, which increases directly in proportion to increasing molecular weight. The compound can furthermore improve the viscosity index of mineral oils. It offers high cohesive and adhesive strength and helps tailoring the "open time" of the adhesive (up to 30 minutes) because of its slow crystallisation kinetics. The main use of PB-1 is in flexible pressure piping systems for hot and cold drinking water distribution, pre-insulated district heating networks and surface heating and cooling systems. PBT resists solvents, shrinks very little during forming, is mechanically strong, is heat-resistant up to 150 C (or 200 C with glass-fibre reinforcement), and can be treated with flame retardants to make it noncombustible. (typically less than 10) The product remains very stable after being prolonged exposure to UV light. Necessary for Google Maps. Catalysts [ edit] To clarify the distinction, polybutene products may have average molecular weights from the hundreds to thousands of grams per mol, but polybutylene type formulations may have average molecular weights in the hundred of thousands to even millions of grams per mol. By controlling the polymerization conditions, polymer chains of different lengths are manufactured giving a wide range of polybutene grades having different physical properties. As one of the worlds leading producers of PIB, we offer the broadest range of polyisobutenes with different molecular weights. vinted justas janauskas fortune polybutene structural formula. Polybutene is allowed by the FDA for a wide variety of applications as components of articles. Butene: Butene is a hydrocarbon that has the chemical formula C 4 H 8. Polybutene's sticky quality therefore is the source of the repellent action of pesticide products containing this active ingredient. 2,5-Furandione, dihydro-, monopolybutenyl derivs. POLYBUTENE may react vigorously with strong oxidizing agents. [7] It is flexible, resists impact well and has good elastic recovery. On this Wikipedia the language links are at the top of the page across from the article title. Polybutylene ( polybutene-1, poly (1-butene), PB-1) is a polyolefin or saturated polymer with the chemical formula (CH 2 CH (Et)) n. Not be confused with polybutene, PB-1 is mainly used in piping. Chemical Guys Cooper Tires EverStart Goodyear Tires Mobil 1 Rain-X. The material can be classified PB 125 with a minimum required strength (MRS) of 12.5 MPa. You can search spectra by . Polybutene mixes well with Hydrogenated Polyisobutene, liquid oils, and esters. . Visit ChemicalBook To find more Polybutene(9003-28-5) information like chemical properties,Structure,melting point,boiling point,density,molecular formula,molecular weight, physical properties,toxicity information,customs codes. Example 1: Draw the 2-dimensional (full display) structural formula for but-2-ene (2-butene), C 4 H 8, given the skeletal formula shown below: Skeletal formula of 2-butene Place a carbon atom at the end of each line (or where two or more lines meet) You choose a product and get all the expertise of TER Chemicals. Depolymerization of waste polybutylene terephthalate in hot compressed water in a fused silica capillary reactor and an autoclave reactor: monomer phase behavior . National Institutes of Health. Polybutene products may be used outdoors or indoors, on buildings or adjacent structures (for example, on girders, beams, ledges, windowsills, gutters, trees, shrubs, and vines) where birds land or roost. 1-BUTENE, HOMOPOLYMER, HOMOPOLYMER 1-BUTENE, and POLYBUTENE. Repeated insult patch tests of 3.150% polybutene in formulations produced, at most, minimal irritation in a small percentage of the test population. This cookie is used to collect analytical information about how visitors use the website. Polybutenes is a hydrophobic material that is derivatized to make anti-rust additives and detergents.. Standard viscosities available are 10, 40 and 100 (mm/s at 100). Indopol polybutenes are synthetic hydrocarbon polymers made by polymerization of C4 olefins (primarily isobutene) and are available in a wide range of viscosities. Corrosionpedia is a part of Janalta Interactive. Polybutene is available in a variety of grades. It is created through the condensation of succinic acid with 1,4-butanediol. [8], International standards set minimum performance requirements for pipes made from PB-1 used in hot water applications. Adhesives PBT is produced by polycondensation of terephthalic acid or dimethyl terephthalate with 1,4-butanediol using special catalysts. Polybutenes undergo combustion, pyrolysis, and autoxidation; the latter two can occur during analytical treatment. You can find our solutions for the relevant product area by clicking on the corresponding symbol. Polybutene is more stable than conventional mineral oil with same APHA color. Polybutenes (PB) are thermoplastic polyolefins with mechanical properties that are between those of polyethylene (PE) and polypropylene (PP). The geometrical isomerism arises when atoms or groups are arranged differently in space due to restricted rotation of a bond or bonds in a molecule. Subscribe to Corrosionpedia for free. 0.0006 ~ 0.0009 expansion coefficient (ml / g. C). Viscosities of different polybutene products can vary; mine is from. Polybutylene terephthalate is used for housings in electrical engineering, but also in automotive construction as plug connectors and in households for example in showerheads or irons. Hydrophobic material is derivatized to make detergents and anti-rust additives. to avoid this in the future, please have your system administrator It is also used synergistically as a blend element to modify the characteristics of other polyolefins like polypropylene and polyethylene. Polybutene-1 is a saturated polymer (polyolefin) of butene-1. A maximum concentration of 82.4% for leave-on products and 20% for rinse off is listed for polybutene (this lower rinse-off level is likely due to it being very difficult to rinse off). endstream endobj 22 0 obj <>stream PB-1 can be foamed. [13][14] The leaks were associated with degradation of polybutylene exposed to chlorinated water. Subscribe to our newsletter to get expert advice and top insights on corrosion science, mitigation and prevention. Non-reproductive organ system toxicity (moderate) and Irritation (skin, eyes, or lungs) (low) SYNONYMS. All rights reserved. Among others, these include oils and fluids, as well as films. Crystal clear liquid. | Head of the Corrosion, Arab Petroleum Pipelines, | Pipeline Coatings Application Consultant, Crest Industrial Chemicals, | Principal Consultant, Bradley Consulting Services, How To Conduct An AC Attenuation Survey on an Underground Pipeline, Anodize This: The Brilliance of Anodizing, How to Prevent Filiform Corrosion Under Coatings, 8 Things to Know and Understand About Iron Corrosion, Top Corrosion Mitigation Technologies to Watch for in 2021, Troubleshooting Cathodic Protection Systems and Function Systems. . Recent Searches. Introduction: polybutene is a binder and viscosity-increasing agent used more in makeup than skin care preparations. Empirical formula of the monomer and of the polymer n-butene CH3CH2CH=CH2 Isobutene H2C=C(CH3) CH2-C . It has a helical conformation in the stable crystalline form. The active ingredient in the catalyst is TiCl4 and the support is microcrystalline MgCl2. It could be something as simple as a run PB-1 piping systems are no longer being sold in North America (see "Class action lawsuits and removal from building code approved usage", below). Its density and hardness will increase during this so-called hexagonal phase. Find polybutene and related products for scientific research at MilliporeSigma . PB-1, when applied as a pure or reinforced resin, can replace materials like metal, rubber and engineering polymers. Problems with leaks and broken pipes led to a class action lawsuit, Cox v. Shell Oil, that was settled for $1 billion. involving your site. In vivo comparison of three different porous materials intended for use in a keratoprosthesis. Its vegan, stable, crystal clear, and doesnt smell like anything. This information is used to compile report and improve site. No significant differences were found after 24 months of feeding in the body weights or weight of food consumption, hematological results, urology, or tumor formation between the animals fed Polybutene and those that were not. endstream endobj 19 0 obj <> endobj 20 0 obj <>/ProcSet 30 0 R/XObject<>>>/Rotate 0/Type/Page>> endobj 21 0 obj <>stream Butene: Butene has a double bond as well as single bonds. Chemical Formula: (C4H8)x; Flash Point: 215 to 470F (USCG, 1999) Those have two functions: On the one hand they are providing basic functionality for this website. Privacy Policy - We are there for you. Toward single-material multifunctional sandwich structures. Polybutene (polybutylene) (PB) is manufactured by stereospecific ZieglerNatta polymerization of l-butene: Polybutene is generally water-white, reaching less than 50 on APHA color scale. Name and Composition Polyisobutylene (PIB) is a synthetic elastomer (a natural or synthetic polymer exhibiting elastic properties) with strong oxygen barrier properties. Polybutene should not be used to refer to higher molecular weight relatives, such as polybutylene (polybutene-1). The pre-catalysts are activated by combinations of organoaluminum compounds and other types of organic or organometallic modifiers. Polybutene is a non-polar hydrocarbon polymer hence it has high solubility in aliphatic, aromatic and chlorinated solvents. Used to store the attribution information, the referrer initially used to visit the website. The mass dependency of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) response has been studied using equimolar mixtures of synthetic discrete mass poly(bu Br. Another reason come from the randomness in its repeating unit composition. Polybutene is prepared from a mixture of butene isomers, which share the same molecular formula (C 4 H 8) but vary in the connectivity of the four carbon atoms and the location of a single carbon-carbon double bond. Due to the COVID-19 pandemic, the global 1,4-Butanediol (BDO) market size is estimated to be worth USD 6132.4 million in 2022 and is forecast to a readjusted size of USD 9570.3 million by 2028 . hbbd``b`J@X$O a H #:q q Find Products. The isomeric forms are 1-butene, cis-2-butene, trans-2-butene, and isobutylene. Melting Point: 104 C: Appearance: pellets: Odor: . Molecular Formula: C4H8: Molar Mass: 56.10632: Density: .91g/mLat 25C(lit.) Recommended Personal Protective Equipment: Goggles or face shield; Symptoms Following Exposure: Low toxicity. average Mn ~920 by VPO, isobutylene >90 %, +undefined-86-13650506873 +undefined-86-13650506873. Unit 1 - MoleculesElaboration - Structural Formulas. View Full Term. PB-1 disperses easily in other polyolefins, and at low concentration, acts as processing aid reducing torque and/or increasing throughput. The brand changed the face of cosmetics by developing . 9003-28-5) SDS CAS No: 9003-28-5 Molecular Weight: 56.10632 Molecular Formula: C 4 H 8 Names and Identifiers Properties Safety and Handling Computational chemical data 18 Suppliers Download SDS (editable Word file) and other types SDS | Offered by XiXisys.com SAFETY DATA SHEETS Mix polybutene with a liquid oil you love to create a rich, shiny, long-wearing lip oil. Polybutylene (polybutene-1, poly (1-butene), POLYBUTENE) is a polyolefin or saturated polymer with the chemical formula (C4H8)n. It should not be confused with polybutene, a low molecular weight oligomer. 0.2~2.0 g/kg for 6 months, no abnormality (rat, oral). Colorless to yellowish viscous liquid, tasteless, odorless or micro-cream special mother odor. Polybutene-1 (PB-1), was discovered in 1954 by the research team of Professor Natta. This website participates in the Formula Botanica, Baraka Shea Butter . Small unsaturated ethene monomers join up by the opening of the double bond allowing them to join up to form a . Define structural formula. It is compatible with a wide variety of organic materials, for instance, synthetic hydrocarboon polymers including wax, rosin, asphalt and gum. PBT, especially glass fibre grades, can be effectively fire-retarded with halogen-free products. Futureproofing New and Existing Pipelines. Polybutenes Linear Formula: [-CH2C (CH3)2-]x[-CH2CH (C2H5)-]y CAS Number: 9003-29-6 Product Comparison Guide Use the product attributes below to configure the comparison table. PREMIUM. Poly(oxy-1,4-butanediyloxycarbonyl-1,4-phenylenecarbonyl), Except where otherwise noted, data are given for materials in their, "Poly(alkylene terephthalate)s: From current developments in synthetic strategies towards applications", "UV Properties of Plastics: Transmission and Resistance", https://en.wikipedia.org/w/index.php?title=Polybutylene_terephthalate&oldid=1136352396, Chemicals that do not have a ChemSpider ID assigned, Articles containing unverified chemical infoboxes, Short description is different from Wikidata, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 29 January 2023, at 23:04. [dubious discuss] Because of its crystalline structure and high molecular weight, PB-1 has good resistance to hydrostatic pressure, showing very low creep even at elevated temperatures. Lowering seal initiation temperature (SIT) of high speed packaging polypropylene based films. Structural formulas are used to describe the 3-dimensional structures of molecules and polyatomic ions. Our polybutenes are used in adhesives and sealants, rubbers, and a number of other applications. A polybutylene terephthalate resin composition is disclosed containing, with respect to 100 parts by mass of a polybutylene terephthalate resin (A) having a carboxylic acid terminal group of 35 meq/kg or less, 0.5 parts by mass or more and 10 parts by mass or less of an epoxy-based resin (B), and a quaternary ammonium salt (C); a molded article comprising the polybutylene terephthalate resin . The availability of polybutene at a variety of molecular weights provides the ability to fine-tune property improvements. Name:Polybutenes,CAS:9003-29-6.Use:Gum base. [11] The use of PB-1 foam as thermal insulation is of great advantage for district heating pipes, since the number of materials in the sandwich structure is reduced to one, facilitating its recycling.[12]. Gum base. Are you looking for specialty chemicals and food additives? Polybutene (CAS No. It also has low creep, excellent chemical resistance, and abrasion resistance with coilability. Feel free to talk to us about your needs. Once cooled, it turns into a soft, elastic material due to its partially tetragonal crystal structure. It does not tend to crack due to stress. This has a natural stretch similar to Lycra and can be incorporated into sportswear. Corrosionpedia Inc. - These cookies are needed for a smooth operation of our website. The Skin Deep ingredient hazard score, from 1 to 10, reflects known and suspected hazards linked to the ingredients. Select Attribute Select Attribute Select Attribute Sort by: Default Product Number Product Description Pricing 388696 Due to its chlorine resistance it is commonly found in swimwear. You may need to do some re-formulating rather than doing a straight one-for-one swap; you might consider adding some lanolin to get a bit of the tacky richness youll be missing from the polybutene. | Pipeline Coatings Application Consultant, Crest Industrial Chemicals, By: Steven Bradley | Principal Consultant, Bradley Consulting Services, Corrosionpedia The online hub for corrosion professionals, Copyright 2023 Articles of Polybutenes are included as well. The compound can be manufactured to various viscosity grades to suit the specific process conditions and polymerization reaction, thus making it a highly versatile chemical. info@ncbi.nlm.nih.gov. 2-Butene is also linear with a formulation of CH 3 CH=CH=CH 3. Several PB-1 grades are commercially available for various applications and conversion technologies (blown film, cast film, extrusion coating). This cookie is used by Google to collect analytical information about how visitors use the website. [further explanation needed], Because the chemical reaction of the water with the pipe occurs inside the pipe, it is often difficult to assess the extent of deterioration. With customers located all over the world, our PIB team acts globally by maintaining strong and caring . polybutylene terephthalate (PBT), a strong and highly crystalline synthetic resin, produced by the polymerization of butanediol and terephthalic acid. PBT and PET need UV protection if used outdoors, and most grades of these polyesters are flammable, although additives can be used to improve both UV and flammability properties. According to CTFA (2006b), laboratory tests with approved surrogate systems/animals revealed that skin contact testing showed only slight irritation (primary dermal irritation score [PDIS] of 1.5/8.0). Brsenbrcke 2, 20457 Hamburg 18 0 obj <> endobj polybutene structural formulagmod tfa base. {Kp0 Luckily, the gentle shea-butter based formula found in eos Shea Butter Dry Skin Shave Cream is formulated especially for those struggling with irritation-prone skin it's even hypoallergenic . Soltex polybutene exhibits good clarity, durability and cling properties, and has food-grade approval for use in food wraps. [8], Polybutylene plumbing was used in several million homes built in the United States from around 1978 to 1997. TER Chemicals is proud to work internationally with supply partners who stand for the highest product quality and reliability. They are suitable for making lubricants, adhesives, sealants, pipes, rubber and food packaging films. Heated up to 190C and above, PB-1 can easily be compression moulded, injection moulded, blown to hollow parts, extruded, and welded. Let's take a look at the compounds vinegar and ethyl alcohol, and compare . Used by DoubleClick (Google Tag Manager) to help identify the visitors by either age, gender or interests. Main applications are in the electrical and electronics (E&E) industry. . The chemical formula of polybutylene succinate is (C8H12O4) n and its melting point is 1.26 g/cm3. Peelable easy-to-open packaging where PB-1 is used as blend component predominantly in polyethylene to tailor peel strength and peel quality, mainly in alimentary consumer packaging and medical packaging. -196C EPA Substance Registry System Polybutene (9003-29-6) More Safety Others Asphalt modifier, resin plasticiser, rubber modifier and dispersing agents. If its being used as a rich emollient in a skincare product, I thinkLanolin, Brassica Campestris Aleurites Fordi Oil Copolymer, orLecithinmight work as an alternative. [2] It is a thermoplastic (semi-)crystalline polymer, and a type of polyester. 4-(4-Piperidinyl)morpholine dihydrochloride, 1,3,7-trimethyl-8-(pyrrolidin-1-yl)-3,7-dihydro-1H-purine-2,6-dione, 1,3,7-Trimethyl-8-(1-pyrrolidinyl)-3,7-dihydro-1H-purine-2,6-dione, 1H-Purine-2,6-dione, 3,7-dihydro-1,3,7-trimethyl-8-(1-pyrrolidinyl)-, 1,3,7-Trimethyl-8-pyrrolidin-1-yl-3,7-dihydro-purine-2,6-dione. Polybutylene terephthalate (PBT) is a thermoplastic engineering polymer that is used as an insulator in the electrical and electronics industries. May react exothermically with reducing agents to release hydrogen gas. temporarily blocked due to a possible misuse/abuse situation Molecular Formula C8H16 Formula Weight 112.21264 MOL File 9003-29-6.mol More POLYBUTENES Property Melting point: 94.3-104.8 C Boiling point: 293-341 C Density 0.908 g/mL at 25 C vapor pressure 19.7hPa at 20 refractive index n 20/D 1.504 Flash point: >230 F storage temp. Polybutene can shrink more if it is cooled down further or subject to greater pressure. With the help of these cookies we strive to improve our offer for our users. They are designed to meet UL 94 flammability tests as well as Glow Wire Ignition Tests (GWIT), Glow Wire Flammability Test (GWFI) and Comparative Tracking Index (CTI). Although polybutene formulations may vary in the molecular weight of the polymers, polybutene refers to the relatively low molecular weight polymers that are liquids at room temperature and pressure.

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