Cov nto moo tshaj plaws thiab siv nyob rau hauv tib neeg lub neej thiab kev lag luam tshuaj teej tug mus rau qeb ntawm polyhydric cawv yog ethylene glycol thiab glycerin. Lawv kev tshawb fawb thiab kev siv tau pib ntau xyoo dhau los, tab sis cov khoom ntawm cov organic tebchaw no muaj ntau txoj hauv kev inimitable thiab tshwj xeeb, uas ua rau lawv indispensable rau niaj hnub no. Polyhydric alcohols yog siv nyob rau hauv ntau yam tshuaj synthesis, industries thiab thaj chaw ntawm tib neeg lub neej.
thawj "kev paub" nrog ethylene glycol thiab glycerin: keeb kwm ntawm kev tau txais
Nyob rau xyoo 1859, dhau los ntawm ob-theem txheej txheem ntawm reacting dibromoethane nrog silver acetate thiab tom qab ntawd kho cov ethylene glycol diacetate tau nyob rau hauv thawj cov tshuaj tiv thaiv nrog caustic potash, Charles Wurtz thawj synthesized ethylene glycol. Qee lub sij hawm tom qab, ib txoj kev ncaj qha hydrolysis ntawm dibromoethane tau tsim, tab sis nyob rau hauv ib qho kev lag luam nplai thaum pib ntawm lub xyoo pua nees nkaum, dihydric cawv 1, 2-dioxyethane, los yog monoethylene glycol, los yog yooj yim glycol, hauv Tebchaws Meskas.tau los ntawm hydrolysis ntawm ethylene chlorohydrin.
Hnub no, ob qho tib si hauv kev lag luam thiab hauv chav kuaj, ntau lwm txoj hauv kev tau siv, tshiab, kev lag luam ntau dua los ntawm cov khoom siv raw thiab lub zog ntawm qhov pom, thiab tus phooj ywg ib puag ncig, txij li kev siv cov tshuaj reagents uas muaj lossis tso cov tshuaj chlorine., co toxins, carcinogens thiab lwm yam khoom txaus ntshai rau ib puag ncig thiab tib neeg, tab tom poob nrog kev txhim kho ntawm "ntsuab" chemistry.
Glycerine tau tshawb pom los ntawm tus kws muag tshuaj Carl Wilhelm Scheele hauv xyoo 1779, thiab Theophile Jules Pelouze tau kawm txog qhov sib xyaw ntawm cov tshuaj hauv xyoo 1836. Ob xyoo caum tom qab, cov qauv ntawm cov molecule ntawm cov cawv trihydric no tau tsim thiab pom tseeb hauv kev ua haujlwm ntawm Pierre Eugene Marseille Vertelot thiab Charles Wurtz. Thaum kawg, nees nkaum xyoo tom qab, Charles Friedel tau ua tiav kev sib txuas ntawm glycerol. Tam sim no, kev lag luam siv ob txoj hauv kev rau nws cov khoom: los ntawm allyl chloride los ntawm propylene, thiab kuj los ntawm acrolein. Cov khoom siv tshuaj lom neeg ntawm ethylene glycol, zoo li glycerin, tau siv dav hauv ntau yam kev tsim tshuaj.
qauv thiab qauv ntawm kev sib txuas
Cov molecule yog ua raws li lub cev tsis muaj zog hydrocarbon pob txha ntawm ethylene, muaj ob lub atoms carbon, uas ob daim ntawv cog lus tau tawg. Ob pawg hydroxyl tau ntxiv rau qhov chaw vacated valence ntawm cov pa roj carbon atoms. Cov mis ntawm ethylene yog C2H4, tom qab rhuav tshem cov nyiaj crane thiab ntxiv hydroxyl pawg (tom qab ob peb theem) nws zoo li C 2N4(OH)2. Qhov ntawd yog qhov nws yogethylene glycol.
Cov ethylene molecule muaj cov qauv linear, thaum lub dihydric cawv muaj ib hom kev hloov pauv hauv qhov chaw ntawm hydroxyl pawg nyob rau hauv kev sib raug zoo nrog cov pa roj carbon monoxide thiab rau ib leeg (lub sij hawm no muaj feem xyuam rau txoj hauj lwm txheeb ze. ntau daim ntawv cog lus). Xws li ib qho dislocation sib raug rau qhov chaw nyob deb tshaj plaws ntawm hydrogens los ntawm cov pab pawg ua haujlwm, qis zog, thiab yog li qhov siab tshaj plaws ntawm qhov system. Yooj yim muab, ib pab pawg OH saib thiab lwm tus saib qis. Nyob rau tib lub sijhawm, cov tebchaw nrog ob hydroxyl tsis ruaj khov: ntawm ib lub atom carbon, raug tsim nyob rau hauv cov tshuaj tiv thaiv sib tov, lawv tam sim ntawd dehydrated, tig mus rau hauv aldehydes.
Kev faib tawm
Cov khoom siv tshuaj ntawm ethylene glycol yog txiav txim los ntawm nws cov hauv paus chiv keeb los ntawm cov pab pawg ntawm polyhydric alcohols, uas yog cov pab pawg ntawm diols, uas yog, cov tebchaw nrog ob qho hydroxyl fragments ntawm cov carbon atoms nyob sib ze. Ib yam khoom uas tseem muaj ntau OH hloov pauv yog glycerol. Nws muaj peb pawg ua haujlwm cawv thiab yog cov tswv cuab feem ntau ntawm nws cov subclass.
Ntau lub tebchaw ntawm cov chav kawm no kuj tau txais thiab siv hauv kev tsim tshuaj lom neeg rau ntau yam kev sib txuas thiab lwm lub hom phiaj, tab sis kev siv ethylene glycol yog qhov hnyav dua thiab koom nrog yuav luag txhua qhov kev lag luam. Qhov teeb meem no yuav tau tham ntxiv hauv qab no.
Lub cev yam ntxwv
Kev siv ethylene glycol yog vim muaj ntau tusCov khoom uas muaj nyob rau hauv polyhydric cawv. Cov no yog cov yam ntxwv tshwj xeeb uas yog tus yam ntxwv nkaus xwb rau chav kawm ntawm cov organic tebchaw.
Qhov tseem ceeb ntawm cov khoom yog qhov tsis muaj peev xwm sib xyaw nrog H 2 O. Dej + ethylene glycol muab cov kev daws teeb meem nrog cov yam ntxwv tshwj xeeb: nws qhov chaw khov, nyob ntawm qhov diol concentration, yog 70 degrees qis dua li cov ntshiab distillate. Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias qhov kev cia siab no tsis yog-linear, thiab thaum ncav cuag ib qho ntawm cov ntsiab lus ntawm glycol, qhov cuam tshuam rov qab pib - qhov chaw khov khov nce nrog qhov nce hauv feem pua ntawm cov khoom yaj. Qhov no feature tau pom daim ntawv thov nyob rau hauv zus tau tej cov antifreezes, anti-freeze kua uas crystallize ntawm tsis tshua muaj thermal yam ntxwv ntawm ib puag ncig.
Tshwj tsis yog hauv dej, cov txheej txheem kev sib cais ua haujlwm zoo hauv cawv thiab acetone, tab sis tsis pom nyob rau hauv paraffins, benzenes, ethers thiab carbon tetrachloride. Tsis zoo li nws cov poj koob yawm txwv aliphatic - xws li cov khoom siv roj xws li ethylene, ethylene glycol yog cov kua txiv hmab txiv ntoo zoo li, pob tshab kua nrog me ntsis daj tint, qab zib hauv saj, nrog cov ntxhiab tsw ntxhiab, xyaum tsis muaj volatile. Kev khov ntawm 100% ethylene glycol tshwm sim ntawm -12.6 degrees Celsius, thiab boiling ntawm +197.8. Nyob rau hauv ib txwm tej yam kev mob, qhov ceev yog 1.11 g / cm3.
Txoj Kev Taug Kev
Ethylene glycol tuaj yeem tau txais ntau txoj hauv kev, qee qhov niaj hnub no tsuas muaj keeb kwm lossis kev npaj tseem ceeb, thaum lwm tusnquag siv los ntawm tus txiv neej ntawm kev lag luam nplai thiab tsis yog xwb. Nyob rau hauv raws sij hawm, cia peb saib qhov tseem ceeb tshaj plaws.
Thawj txoj hauv kev kom tau ethylene glycol los ntawm dibromoethane twb tau piav qhia saum toj no. Cov mis ntawm ethylene, ob daim ntawv cog lus uas tau tawg, thiab cov khoom siv dawb yog nyob ntawm halogens, cov khoom siv tseem ceeb hauv cov tshuaj tiv thaiv no, ntxiv rau carbon thiab hydrogen, muaj ob lub bromine atoms nyob rau hauv nws muaj pes tsawg leeg. Kev tsim ntawm ib qho kev sib txuas nruab nrab ntawm thawj theem ntawm cov txheej txheem yog ua tau raws li lawv cov kev tshem tawm, piv txwv li, hloov los ntawm acetate pawg, uas, thaum ntxiv hydrolysis, tig mus rau hauv cawv.
Nyob rau hauv cov txheej txheem ntawm kev txhim kho ntxiv ntawm kev tshawb fawb, nws tau dhau los ua kom tau ethylene glycol los ntawm kev ncaj qha hydrolysis ntawm ethanes hloov los ntawm ob halogens ntawm cov atoms nyob sib ze, siv cov tshuaj aqueous ntawm cov hlau carbonates los ntawm pawg alkaline lossis (tsawg dua ib puag ncig. tus phooj ywg reagent) H2 Oh thiab lead dioxide. Cov tshuaj tiv thaiv yog heev "kev ua haujlwm hnyav" thiab tsuas yog nce siab ntawm qhov kub thiab txias, tab sis qhov no tsis tiv thaiv cov neeg German los ntawm kev siv cov qauv no thaum lub ntiaj teb ua tsov ua rog los tsim ethylene glycol ntawm kev lag luam.
Txoj kev tau txais ethylene glycol los ntawm ethylene chlorohydrin los ntawm nws cov hydrolysis nrog carbon ntsev ntawm alkali pab pawg hlau kuj tau ua nws lub luag haujlwm hauv kev tsim cov organic chemistry. Nrog rau qhov nce ntawm qhov ntsuas kub mus rau 170 degrees, cov txiaj ntsig ntawm cov khoom lag luam tau mus txog 90%. Tab sis muaj ib qho teeb meem tseem ceeb - glycol yuav tsum tau muab rho tawm los ntawm cov ntsev ntsev, uas yog ncaj qha ntsig txog.ib tug xov tooj ntawm kev nyuaj. Cov kws tshawb fawb daws qhov teeb meem no los ntawm kev tsim ib txoj hauv kev nrog tib yam khoom pib, tab sis tawg cov txheej txheem ua ob theem.
Ethylene glycol acetate hydrolysis, yog theem kawg ua ntej ntawm Wurtz txoj kev, tau los ua ib txoj kev sib cais thaum lawv tswj kom tau txais qhov pib reagent los ntawm oxidizing ethylene hauv acetic acid nrog oxygen, uas yog, tsis siv cov nqi kim thiab tag nrho unenvironmental halogen compounds.
Tseem muaj ntau txoj hauv kev los tsim ethylene glycol los ntawm oxidizing ethylene nrog hydroperoxides, peroxides, organic peracids nyob rau hauv lub xub ntiag ntawm catalysts (osmium compounds), poov tshuaj chlorate, thiab lwm yam. Tseem muaj electrochemical thiab hluav taws xob-tshuaj txoj kev.
Tus yam ntxwv ntawm cov khoom siv tshuaj lom neeg
Cov khoom siv tshuaj ntawm ethylene glycol yog txiav txim siab los ntawm nws pawg ua haujlwm. Cov tshuaj tiv thaiv yuav koom nrog ib qho kev hloov pauv hydroxyl lossis ob qho tib si, nyob ntawm cov txheej txheem txheej txheem. Lub ntsiab sib txawv ntawm reactivity nyob rau hauv qhov tseeb hais tias vim muaj ntau hydroxyl nyob rau hauv ib tug polyhydric cawv thiab lawv cov kev sib raug zoo, muaj zog acidic zog yog manifested tshaj li cov monohydric "cov kwv tij". Yog li ntawd, hauv cov tshuaj tiv thaiv alkalis, cov khoom lag luam yog ntsev (rau glycol - glycolates, rau glycerol - glycerates)
Cov khoom siv tshuaj ntawm ethylene glycol, nrog rau glycerin, suav nrog txhua qhov kev cuam tshuam ntawm cawv los ntawm qeb ntawm monohydric. Glycol muab tag nrho thiab ib nrab esters hauv kev cuam tshuam nrog monobasic acids, glycolates, feem, yog tsim nrog alkali hlau, thiab thaum twgNyob rau hauv cov txheej txheem tshuaj uas muaj zog acids los yog lawv cov ntsev, acetic acid aldehyde raug tso tawm - vim yog tshem tawm ntawm hydrogen atom los ntawm ib lub molecule.
Reactions with active metals
Cov tshuaj tiv thaiv ethylene glycol nrog cov hlau nquag (tom qab hydrogen hauv tshuaj muaj zog tshuaj series) ntawm qhov kub siab ua rau ethylene glycolate ntawm cov hlau sib txuas, ntxiv rau hydrogen tso tawm.
C2N4(OH)2 + X → C2H4O2X, qhov twg X yog lub active divalent hlau.
Cov tshuaj tiv thaiv zoo rau ethylene glycol
Txhais qhov dej cawv polyhydric los ntawm lwm cov kua uas siv cov tshuaj tiv thaiv kev pom uas yog tus yam ntxwv nkaus xwb rau chav kawm ntawm cov tebchaw. Ua li no, freshly precipitated tooj liab hydroxide (2), uas muaj ib tug yam ntxwv xiav tint, yog poured rau hauv ib tug colorless kua ntawm cawv. Thaum cov khoom sib xyaw ua ke sib cuam tshuam, cov nag lossis daus yaj thiab cov tshuaj hloov mus rau hauv cov xim xiav sib sib zog nqus - vim yog qhov tsim ntawm tooj liab glycolate (2).
YPolymerization
Cov khoom siv tshuaj ntawm ethylene glycol yog qhov tseem ceeb rau kev tsim cov kuab tshuaj. Lub cev qhuav dej ntawm cov tshuaj tau hais, uas yog, tshem tawm cov dej los ntawm txhua qhov ntawm ob lub molecules ntawm glycol thiab lawv cov kev sib xyaw ua ke tom qab (ib pawg hydroxyl raug tshem tawm tag nrho, thiab tsuas yog hydrogen raug tshem tawm los ntawm lwm tus), ua rau kom tau txais. Ib qho tshwj xeeb organic hnyav - dioxane, uas feem ntau yog siv hauv cov organic chemistry, txawm tias nws muaj toxicity.
Hydroxy exchangerau halogen
Thaum ethylene glycol cuam tshuam nrog hydrohalic acids, kev hloov ntawm hydroxyl pawg los ntawm cov halogen sib raug tau pom. Qib ntawm kev hloov pauv nyob ntawm qhov molar concentration ntawm hydrogen halide hauv cov tshuaj tiv thaiv sib xyaw:
HO-CH2-CH2-OH + 2HX → X-CH2 -CH2-X, qhov twg X yog chlorine lossis bromine.
Tau Ether
Hauv cov tshuaj tiv thaiv ntawm ethylene glycol nrog nitric acid (ntawm ib qho concentration) thiab monobasic organic acids (formic, acetic, propionic, butyric, valeric, thiab lwm yam), complex thiab, raws li, yooj yim monoesters yog tsim. Ntawm lwm tus, cov concentration ntawm nitric acid yog glycol di- thiab trinitroesters. Sulfuric acid ntawm ib qho concentration yog siv los ua catalyst.
Qhov tseem ceeb tshaj plaws ntawm ethylene glycol
Cov khoom muaj txiaj ntsig uas tuaj yeem tau txais los ntawm polyhydric cawv siv cov tshuaj lom neeg yooj yim (piv txwv li saum toj no) yog ethylene glycol ethers. Namely: monomethyl thiab monoethyl, cov qauv uas yog HO-CH2-CH2-O-CH3 thiab HO-CH2-CH2-O-C2N5 raws. Hais txog cov khoom siv tshuaj lom neeg, lawv muaj ntau txoj hauv kev zoo ib yam li glycols, tab sis, zoo li lwm chav kawm ntawm cov khoom sib txuas, lawv muaj cov yam ntxwv tshwj xeeb uas yog tshwj xeeb rau lawv:
- Monomethylethylene glycol yog cov kua tsis muaj xim, tab sis nrog cov yam ntxwv qias neeg tsw, boiling ntawm 124.6 degrees Celsius, heev soluble nyob rau hauv ethanol, lwm yamorganic solvents thiab dej, ntau volatile tshaj glycol, thiab nrog ib tug ceev tsawg tshaj li cov dej (ntawm qhov kev txiav txim ntawm 0.965 g / cm3).
- Dimethylethylene glycol kuj yog cov kua, tab sis nrog cov yam ntxwv tsis tshua muaj ntxhiab tsw, qhov ntom ntawm 0.935 g / cm3 3, qhov kub ntawm 134 degrees saum xoom thiab qhov sib piv. rau yav dhau los homologue.
Kev siv cov cellosolves - raws li ethylene glycol monoethers feem ntau hu ua - yog qhov ntau heev. Lawv yog siv los ua reagents thiab cov kuab tshuaj hauv cov organic synthesis. Lawv lub cev muaj zog kuj yog siv los tiv thaiv corrosion thiab tiv thaiv crystallization additives nyob rau hauv antifreeze thiab motor oils.
Daim ntawv thov thiab nqi ntawm cov khoom lag luam
Tus nqi ntawm cov chaw tsim khoom thiab cov lag luam koom nrog hauv kev tsim khoom thiab muag cov tshuaj reagents fluctuates nyob rau nruab nrab ntawm 100 rubles ib kilogram ntawm xws li tshuaj lom neeg xws li ethylene glycol. Tus nqi nyob ntawm qhov purity ntawm cov khoom thiab qhov siab tshaj plaws feem pua ntawm cov khoom lag luam.
Kev siv ethylene glycol tsis txwv rau ib cheeb tsam. Yog li, raws li ib tug raw khoom nws yog siv nyob rau hauv zus tau tej cov organic solvents, dag resins thiab fibers, kua uas khov nyob rau hauv qis kub. Nws koom nrog ntau yam lag luam xws li automotive, aviation, kws tshuaj, hluav taws xob, tawv, luam yeeb. Nws qhov tseem ceeb rau cov organic synthesis yog qhov hnyav heev.
Nws yog ib qho tseem ceeb kom nco ntsoov tias glycol yogtoxic compound uas yuav ua rau irreparable ua phem rau tib neeg noj qab haus huv. Yog li ntawd, nws yog khaws cia rau hauv cov thawv ntim khoom ua los ntawm txhuas lossis hlau nrog cov txheej txheem sab hauv uas yuav tsum tau tiv thaiv lub thawv los ntawm corrosion, tsuas yog nyob rau hauv txoj hauj lwm ntsug thiab hauv cov chav uas tsis tau nruab nrog cua sov, tab sis muaj qhov cua zoo. Lub sij hawm - tsis tshaj tsib xyoos.
