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Hexamethylene Diisocyanate
Hexamethylene diisocyanate (HDI) is the organic compound with the formula (CH2)6(NCO)2. It is classified as an diisocyanate. It is a colorless liquid. It has sometimes been called HMDI but this not usually done to avoid confusion with Hydrogenated MDI. Synthesis Compared to other commercial diisocyanates, HDI is produced in relatively small quantities, accounting for (with isophorone diisocyanate) only 3.4% of the global diisocyanate market in the year 2000. It is produced by phosgenation of hexamethylene diamine. Applications Aliphatic diisocyanates are used in specialty applications, such as enamel coatings which are resistant to abrasion and degradation by ultraviolet light. These properties are particularly desirable in, for instance, the exterior paint applied to aircraft and vessels. HDI is also sold oligomerized as the trimer or biuret which are used in automotive refinish coatings. Although more viscous in these forms, it reduces the volatility and toxicity. At least 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poise (unit)
The poise (symbol P; ) is the unit of dynamic viscosity (absolute viscosity) in the centimetre–gram–second system of units (CGS). It is named after Jean Léonard Marie Poiseuille (see Hagen–Poiseuille equation). The centipoise (1 cP = 0.01 P) is more commonly used than the poise itself. Dynamic viscosity has dimensions of \mathrm, that is, [\mathsf^1 \mathsf^ \mathsf^]. 1~\text = 0.1~\text^ \text \text^ = 1~\text^ \text \text^ = 1~\text \text \text^. The analogous unit in the SI, International System of Units is the pascal-second (Pa⋅s): 1~\text \text = 1~\text \text \text^ = 1~\text^ \text \text^ = 10~\text. The poise is often used with the metric prefix ''centi-'' because the viscosity of water at 20 °C (standard conditions for temperature and pressure) is almost exactly 1 centipoise. A centipoise is one hundredth of a poise, or one millipascal-second (mPa⋅s) in SI units (1 cP = 10−3 Pa⋅s = 1 mPa⋅s). The CGS symbol fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isocyanate
In organic chemistry, isocyanate is the functional group with the formula . Organic compounds that contain an isocyanate group are referred to as isocyanates. An organic compound with two isocyanate groups is known as a diisocyanate. Diisocyanates are manufactured for the production of polyurethanes, a class of polymers. Isocyanates should not be confused with cyanate esters and isocyanides, very different families of compounds. The cyanate (cyanate ester) functional group () is arranged differently from the isocyanate group (). Isocyanides have the connectivity , lacking the oxygen of the cyanate groups. Structure and bonding In terms of bonding, isocyanates are closely related to carbon dioxide (CO2) and carbodiimides (C(NR)2). The C−N=C=O unit that defines isocyanates is planar, and the N=C=O linkage is nearly linear. In phenyl isocyanate, the C=N and C=O distances are respectively 1.195 and 1.173 Å. The C−N=C angle is 134.9° and the N=C=O angle is 173.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isophorone Diisocyanate
Isophorone diisocyanate (IPDI) is an organic compound in the class known as isocyanates. More specifically, it is an Aliphatic compound, aliphatic diisocyanate. It is produced in relatively small quantities, accounting for (with hexamethylene diisocyanate) only 3.4% of the global diisocyanate market in the year 2000. Aliphatic diisocyanates are used, not in the production of polyurethane foam, but in special applications, such as enamel coatings which are resistant to Abrasion (mechanical), abrasion and degradation from Ultraviolet, ultraviolet light. These properties are particularly desirable in, for instance, the exterior paint applied to aircraft. Properties Isophorone diisocyanate (IPDI) stands out as a cycloaliphatic diisocyanate distinguished by its two reactive isocyanate groups, exhibiting differences in reactivity between primary and secondary NCO groups. This unique property ensures high selectivity in reacting with hydroxyl-bearing compounds. This distinctive attrib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-containing compounds such as alkanes (e.g. methane ) and its derivatives are universally considered organic, but many others are sometimes considered inorganic, such as certain compounds of carbon with nitrogen and oxygen (e.g. cyanide ion , hydrogen cyanide , chloroformic acid , carbon dioxide , and carbonate ion ). Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, and even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogenated MDI
Hydrogenated MDI (H12MDI or 4,4′-diisocyanato dicyclohexylmethane) is an organic compound in the class known as isocyanates. More specifically, it is an aliphatic diisocyanate. It is a water white liquid at room temperature and is manufactured in relatively small quantities. It is also known as 4,4'-methylenedi(cyclohexyl isocyanate) or methylene bis(4-cyclohexylisocyanate) and has the formula CH2 C6H10)NCOsub>2. Manufacture The product is manufactured by hydrogenation of methylene diphenyl diisocyanate. It may also be manufactured by phosgenation of 4,4-Diaminodicyclohexylmethane. Uses Aliphatic diisocyanates are not used in the production of polyurethane foam as the cost is too high and foam is very much a commodity. It is used in special applications for polyurethane, such as enamel coatings which are resistant to abrasion and degradation from ultraviolet light. There are also multiple patents where prepolymers based on it are used in golf ball production. It is available comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isophorone Diisocyanate
Isophorone diisocyanate (IPDI) is an organic compound in the class known as isocyanates. More specifically, it is an Aliphatic compound, aliphatic diisocyanate. It is produced in relatively small quantities, accounting for (with hexamethylene diisocyanate) only 3.4% of the global diisocyanate market in the year 2000. Aliphatic diisocyanates are used, not in the production of polyurethane foam, but in special applications, such as enamel coatings which are resistant to Abrasion (mechanical), abrasion and degradation from Ultraviolet, ultraviolet light. These properties are particularly desirable in, for instance, the exterior paint applied to aircraft. Properties Isophorone diisocyanate (IPDI) stands out as a cycloaliphatic diisocyanate distinguished by its two reactive isocyanate groups, exhibiting differences in reactivity between primary and secondary NCO groups. This unique property ensures high selectivity in reacting with hydroxyl-bearing compounds. This distinctive attrib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosgenation
Phosgene is an organic chemical compound with the formula . It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. It can be thought of chemically as the double acyl chloride analog of carbonic acid, or structurally as formaldehyde with the hydrogen atoms replaced by chlorine atoms. In 2013, about 75–80 % of global phosgene was consumed for isocyanates, 18% for polycarbonates and about 5% for other fine chemicals. Phosgene is extremely poisonous and was used as a chemical weapon during World War I, where it was responsible for 85,000 deaths. It is a highly potent pulmonary irritant and quickly filled enemy trenches due to it being a heavy gas. It is classified as a Schedule 3 substance under the Chemical Weapons Convention. In addition to its industrial production, small amounts occur from the breakdown and the combustion of organochlorine compounds, such as chloroform. Structure and basic properties Phosgene is a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexamethylene Diamine
Hexamethylenediamine or hexane-1,6-diamine, is the organic compound with the formula H2N(CH2)6NH2. The molecule is a diamine, consisting of a hexane, hexamethylene hydrocarbon chain terminated with amine functional groups. The colorless solid (yellowish for some commercial samples) has a strong amine odor. Synthesis Hexamethylenediamine was first reported by Theodor Curtius. It is produced by the hydrogenation of adiponitrile: :NC(CH2)4CN + 4 H2 → H2N(CH2)6NH2 The hydrogenation is conducted on molten adiponitrile diluted with ammonia, typical catalysts being based on cobalt and iron. The yield is good, but commercially significant side products are generated by virtue of reactivity of partially hydrogenated intermediates. These other products include 1,2-diaminocyclohexane, hexamethyleneimine, and the triamine bis(hexamethylenetriamine). An alternative process uses Raney nickel as the catalyst and adiponitrile that is diluted with hexamethylenediamine itself (as the sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biuret
Biuret ( ) is a chemical compound with the chemical formula . It is a white solid that is soluble in hot water. A variety of organic derivatives are known. The term "biuret" also describes a family of organic compounds with the chemical formula , where are hydrogen, organyl or other groups. Also known as carbamylurea, it results from the condensation of two equivalents of urea. It is a common undesirable impurity in urea-based fertilizers, as biuret is toxic to plants. Preparation and structure The parent compound can be prepared by heating urea at 150 °C for ~6 hours until it gets slightly cloudy, then recrystallizing from water. After that, it can be recrystallized repeatedly from 2% sodium hydroxide solution and water to finally get base-free crystalline needles of the monohydrate which are free of cyanuric acid. While heating, a lot of ammonia is expelled: : Under related conditions, pyrolysis of urea affords triuret . In general, organic biurets (those with alkyl or aryl gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxazolidine
Oxazolidine is a five-membered heterocycle ringwith the formula .The O atom and NH groups are not mutually bonded, in contrast to isoxazolidine. Oxazolidines (emphasis on plural) are derivatives of the parent oxazolidine owing to the presence of substituents on carbon and/or nitrogen. Oxazolines are unsaturated analogues of oxazolidines. Synthesis and reactions First synthesized in the 1800s, oxazolidines are traditionally prepared by condensation of 2- aminoalcohols with aldehydes and ketones. The ready availability of chiral amino alcohols by reduction of amino acids enables the synthesis of chiral oxazolidines. Oxazolidines are prone to hydrolysis, the reverse of their syntheses. Perhaps for this reason, their basicity is rarely discussed. Uses and occurrence Several oxazolidine derivatives occur naturally, Some occur as post translational modifications of proteins. Others are components of alkaloids, a few of which are highly active against some tumors. Examples include ... [...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] |
Toluene Diisocyanate
Toluene diisocyanate (TDI) is an organic compound with the formula CH3C6H3(NCO)2. Two of the six possible isomers are commercially important: 2,4-TDI (CAS: 584-84-9) and 2,6-TDI (CAS: 91-08-7). 2,4-TDI is produced in the pure state, but TDI is often marketed as 80/20 and 65/35 mixtures of the 2,4 and 2,6 isomers respectively. It is produced on a large scale, accounting for 34.1% of the global isocyanate market in 2000, second only to MDI. Approximately 1.4 billion kilograms were produced in 2000. All isomers of TDI are colorless, although commercial samples can appear yellow. Synthesis 2,4-TDI is prepared in three steps from toluene via dinitrotoluene and 2,4-diaminotoluene (TDA). Finally, the TDA is subjected to ''phosgenation'', i.e., treatment with phosgene to form TDI. This final step produces HCl as a byproduct and is a major source of industrial hydrochloric acid. : Distillation of the raw TDI mixture produces an 80:20 mixture of 2,4-TDI and 2,6-TDI, known as TDI (80 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
