Chlorofluorocarbons or cfcs also wellknown as freon are nontoxic, nonflammable and noncarcinogenic. Analysis of hydro fluoro carbons to reduce ozone depletion. Nucleophilic substitution of fluoro, chloro, and nitro groups was described for benzofuroxans. The environmental code of practice for elimination of fluorocarbon emissions from. Rosskya,b,1 adepartments of chemical engineering and bchemistry and biochemistry and institute for computational engineering and sciences, university of texas, austin, tx 78712 edited by john d.
Toxic and hazarous industrial chemicals safety manual. Hide folders, software gratisan untuk menyembunyik. Fluorocarbons, sometimes referred to as perfluorocarbons or pfcs, are, strictly speaking, organofluorine compounds with the formula c x f y, i. Synthesis, characterization and antimicrobial activity of.
Chlorofluorocarbon simple english wikipedia, the free. Elastomer types natural synthetic polyisoprene styrabutadiene ethylene propylene diomene monomer nitrile bunan chloro prene neoprene fluorocarbon polymer viton astm designation nr ir sbr epdm nbr cr fpm service temp. Cfc chloro fluoro carbon, sebagai penyebab menipisnya. Pdf 65chloro2trifluoromethylphenyl3fluoro2methylpyridine. This process, patented by shapovalov 1980, gets its name from combining the word gas with an. Cfc adalah singkatan dari chloroflourocarbon yang terbentuk dari atom chlor, flour, dan carbon. When cfcs also contain hydrogen in place of one or more chlorines, they are called hydrochlorofluorocarbons, or hcfcs. Pdf suzuki coupling reaction of 5fluoro6methylpyridin2ylboronic acid 1 with 4chloro2iodo1trifluoromethylbenzene 2 in the presence of. An experimental study was performed to obtain design data for a cool storage system using hcfc. Esempi di clorofluorocarburi sono il diclorodifluorometano, ccl 2 f 2, e il diclorotetrafluoroetano, cclf 2 cclf 2. Straight chain alkanes have only carbon and hydrogen atoms. The refrigerant r22 which is extensively used in air. Lievens, january 2012 university of california, davis chemistry 118 series 6 examples.
Elastomer types natural synthetic styra ethylene nitrile. Central drug house p ltd 728 vardaan house new delhi2. Ciclo biogeoquimico del cloro cl by christian grajales on prezi. With lowboiling alcohols meoh, etoh, the reactions were heated under reflux using the alcohol as a solvent and excess of potassium hydroxide table 1, entries 1 and 2. Cfcs chloro fluoro carbons are greenhouse gases that have caused a rise of 0. Hcfc124 1,1,1,2tetrafluorochloroethane, introduced comparatively recently, is an aerosol propellant. Nucleophilic aromatic substitution of fluorine leading to compounds 3 was investigated table 1. Fluorine bond cleavage through hydroxylation promoted by a histidylligated heme enzyme yifan wang, ian davis, inchul shin, daniel j.
Chlorofluorocarbons cfc are gases used for various purposes including solvents,refrigerants and aerosol sprays. They are organic chemicals and contain carbon, sometimes hydrogen, chlorine, and fluorine. These exceptional properties are because of the fluorine sheath that protects the carbon backbone from chemical attack resulting in a hydrophobic polymer with low surface energy. Colabroy, and aimin liu, department of chemistry, university of texas, san antonio, texas 78249, united states. Cfc merupakan gas yang berwarna biru tua, stabil, tidak mudah terbakar, mudah disimpan, dan murah harganya. Hcfc, and hfc and compressed gases nitrogen, nitrous oxide, and carbon dioxide 1. Chlorofluorocarbon definition of chlorofluorocarbon by the.
Clorofluorocarboneto wikipedia, a enciclopedia livre. Synthesis and characterization of coreshell colloids with. Environmental code of practice for the elimination of fluorocarbon. Pdf chlorofluorocarbons cfcs and their effect on the. Alerta sobre os perigos letais do cloro e fluor na agua. As in simpler alkanes, carbon in the cfcs bonds with tetrahedral symmetry. For alcohols with higher boiling points, the reactions were performed with sodium hydride table 1, entries 3 and 4. Chlorofluorocarbon cfc is an organic compound that contains carbon, chlorine, and fluorine, produced as a volatile derivative of methane and ethane. Rubber material selection guide fkm or fluorocarbon.
The invention discloses a kind of synthetic method of favipiravir, aromatic ring fluoro reaction, cyanhydrolysis reaction and aromatic ring hydroxyl substitution reaction that the carboxylic acid of 3 aminopyrazine 2 is connected with alcohol generation esterification, bromination reaction, diazoreaction, ammonolysis reaction, chloro dehydration and one pot, subsequent treatment purified. Biocatalytic carbonhydrogen and carbonfluorine bond. Volatile chlorofluorocarbons are believed to cause depletion of the atmospheric ozone layer. Corrispondono agli idrocarburi nei quali tutti o parte degli atomi didrogeno sono stati sostituiti da atomi di cloro e fluoro. Esempi di clorofluorocarburi sono il diclorodifluorometano, ccl2f2, e il diclorotetrafluoroetano, cclf2cclf2.
Hcfcs, methyl bromide and carbon tetrachloride have the largest number of feedstock uses. Tambien puedes comparar cloro con otros elementos como por ejemplo bromo, azufre, argon o helio. They were much used in the middle 20th century, replacing chemicals that were toxic or flammable or had other problems. Chlorofluorocarbon definition, any of several volatile, inert, saturated compounds of carbon, fluorine, chlorine, and hydrogen. Hydrocarbon production was ended in 1996 in some countries lpmdluctioltil wm be eltildledlby 2 niol fum some cowml no restrictions at this time. The invention of chlorofluorocarbons cfcs in the late 1920s and early 1930s stemmed from the call for safer alternatives to the sulfur dioxide and ammonia refrigerants used at the time, cfcs found wide. Synthesis, characterization and antimicrobial activity of fluoro benzothiazole incorporated with 1,3,4thiadiazole.
Synthesis and nucleophilic aromatic substitution of 3. The development of fluorocarbon refrigerants, freon, was announced in april 1930. They mainly contains fluorine atoms, carbon atoms and chlorine atoms. Chlorofluorocarbons cfcs and hydrochlorofluorocarbons hcfcs are fully or partly. Cfc any of various halocarbon compounds consisting of carbon, hydrogen, chlorine, and fluorine, once used widely as aerosol propellants and refrigerants. A special numbering system is to be used for fluorinated alkanes, prefixed with freon, r, cfc and hcfc, where the rightmost value indicates the number of fluorine atoms, the next value to the left is the number of hydrogen atoms plus 1, and the next value to the left is the number of carbon atoms less one zeroes are not stated, and the remaining atoms are chlorine. Compounds with the prefix perfluoroare hydrocarbons, including those with heteroatoms, wherein all ch bonds have been replaced by cf bonds. Cfc chloro fluoro carbon, sebagai penyebab menipisnya lapisan ozon labels. For example, 56 fluoro 65substituted benzofuroxans were obtained by the reactions of 5,6difluorobenzofuroxan with a number of nucleophiles, such as alkylamines, cycloalkylimines, sodium azide, and sodium alkoxides. Cfcs or chloro fluoro carbon are simply made of elements carbon, fluorine and chlorine. A manual should be prepared for the system and all its assembled components including the alarms and. Chlorofluorocarbon definition of chlorofluorocarbon at. It is also called carbon chloride, methane tetrachloride, perchloromethane, tetrachloroethane. They are several organic compounds composed of carbon, fluorine, chlorine, and hydrogen.
In 1978, sweden became the first country that banned cfc products. Permitted chlorofluoroalkane uses are medicinal only. Sono caratterizzati da elevata stabilita chimica e termica, che aumenta con il contenuto di fluoro, sono ininfiammabili e poco tossici. Chlorofluorocarbon cfc, any of several organic compounds composed of carbon, fluorine, and chlorine. This chloro fluorocarbon solvent r1 contains air mixed thereinto. Denominazione collettiva di una classe di composti chimici ottenibili dagli idrocarburi sostituendo una parte degli atomi di idrogeno con atomi di cloro e fluoro. Synthesis and characterization of coreshell colloids with fluorocarbon cores article in macromolecular symposia 1511.
Airconditioning and refrigeration institute arl is foimed through a merger of. Hydrocarbon refrigerants a propaneisobutane blend were also used extensively in mobile air. Molecular origins of fluorocarbon hydrophobicity vishwanath h. Cn106866553a a kind of synthetic method of favipiravir. Chlorofluorocarbon definition of chlorofluorocarbon by. Hydrochlorofluorocarbon an overview sciencedirect topics. The production of cfcs, chloro fluorocarbon means a carbonic compound with chlorine and fluorine, has been prohibited by the montreal protocol in order to prevent the destruction of the ozone layer.
139 1063 833 1476 735 472 380 634 570 578 1369 169 316 887 854 788 159 120 156 1539 1224 1312 1279 52 1145 289 324 964 1258 1425 97 711 132 836 244 1198 989 581