Yuav ua li cas hluavtaws isoprene roj hmab ua

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2024-01-02 13:55

Natural roj hmab muaj ntau yam analogues, thiab isoprene roj hmab yog suav hais tias yog ib qho ntawm feem ntau tonnage. Kev lag luam tsim ntau yam ntawm cov khoom siv no, sib txawv ntawm cov khoom thiab hauv hom catalysts uas tau siv - lithium, complex, thiab lwm yam.

Yuav ua li cas roj hmab

Isoprene roj hmab yog hluavtaws, nws yog stereoregular, thiab nws tau los ntawm polymerization ntawm isoprene muab tso rau hauv ib qho inert hnyav nruab nrab nrog ib tug complex catalyst. Qhov no ua tiav, piv txwv li, SKI-3. Lub polymerization ntawm isoprene nyob rau hauv kev daws yuav tsum tas mus li, rau qhov no muaj cov roj teeb ntawm plaub mus rau rau lub polymerizers uas yog txias nrog brine.

Lub monomer hauv qhov sib tov yog concentrated rau kaum ob - kaum tsib feem pua, ces qhov kev hloov pauv yuav ncav cuag cuaj caum-tsib feem pua, thiab lub sijhawm yuav yog ob mus rau peb teev ntawm qhov kub ntawm xoom mus rau kaum degrees Celsius. Yog tias tsim nyog kom tau txais qhov hnyav molecular hnyav isoprene roj hmab, purity ntawm cov reagents siv nyob rau hauv lub polymerization yog heev.high degree.

Stabilizing thiab ziab

Txhawm rau tiv thaiv cov polymer los ntawm oxidation, nws yuav tsum ruaj khov nrog kev sib xyaw ntawm phenylenediamine thiab neozone, uas yuav tsum tau nkag mus rau hauv polymerizate raws li kev daws teeb meem lossis aqueous suspension. Txhawm rau cais cov roj hmab isoprene los ntawm cov polymerization raws li cov khoom tawg, cov polymerizate yuav tsum tau tov nrog chav thiab dej, tom qab ntawd ntxiv cov khoom ntxiv uas tiv thaiv agglomeration (lumping). Tom qab ntawd cov kuab tshuaj yuav tsum tau distilled. Tam sim no nws yog ib qho tsim nyog los ua kom tiav cov txheej txheem ntawm degassing, cais cov crumbs los ntawm dej thiab ziab hauv cov cav tov cab thiab siv tshuab ziab khaub ncaws. Thaum kawg ntawm cov txheej txheem no, kev tsim cov roj hmab isoprene tuaj yeem suav tias ua tiav.

Tam sim no nws yuav briquetting ntawm cov nroj tsuag tsis siv neeg nyob rau hauv siab. Hom SKI-3 - hluavtaws isoprene roj hmab, uas yog tsim nyob rau hauv briquettes ntawm peb caug kilograms txhua. Lub briquette yog qhwv hauv zaj duab xis polyethylene thiab muab tso rau hauv ib lub hnab ntawv plaub-txheej. Cov yeeb yaj kiab no tau ua tiav zoo ib txhij nrog cov ntsiab lus, uas yog cov roj hmab isoprene, nws cov khoom sib xyaw nrog qhov kub thiab txias heev tso cai rau polyethylene soften thiab sib tov nrog cov loj loj hauv cov roj hmab tov khoom.

qauv

Txhua cov roj hmab uas tsim los ntawm kev lag luam muaj nws tus yam ntxwv thiab cov khoom muaj nyob rau hauv ntau yam no. Qee cov roj hmab muaj lub zog zoo txhua yam, lwm tus muaj cov tshuaj tiv thaiv zoo lossis roj impermeability, lwm tus tsis muaj kev ntshai ntawm kev hloov pauv kub, thiab lwm yam. Cov khoomib tug neeg hluavtaws roj hmab yog superior rau tej yam ntuj tso roj hmab nyob rau hauv ntau txoj kev thiab ntau zaus tshaj. Tsuas yog cov elasticity ntawm cov roj hmab ntuj tseem tsis tau dhau mus, thiab qhov no yog cov cuab yeej tseem ceeb tshaj plaws rau cov khoom xws li dav hlau lossis tsheb log tsheb.

Thaum lub sijhawm ua haujlwm, lawv ib txwm muaj kev deformation loj - ob qho tib si ncab thiab compression, uas ua rau muaj kev sib txhuam sib txuas, cua sov thiab tsis zoo. Ntawd yog, qhov siab dua elasticity ntawm cov roj hmab, cov khoom siv ntev dua. Nws yog vim li no tias cov roj hmab ntuj tseem tsis tau tawm ntawm kev siv, thiab nws yog nws uas yog siv rau kev tsim cov log tsheb rau kev kub ceev thiab lub luag haujlwm hnyav thiab lub tsheb. Cov roj hmab ntuj yog cov polymer ntawm isoprene, uas yog vim li cas cov kws tshawb fawb tau ua haujlwm hnyav heev los ua cov roj hmab isoprene ib qho analogue ntawm cov roj hmab ntuj.

Formula

Cov peev txheej rau rho tawm cov roj hmab ntuj muaj tsawg heev. Ib txwm, ib txwm tshwm sim roj hmab muaj cov mis C₅H₈, raws li nws tau muab tawm, nws yog kiag li zoo tib yam rau cov mis molecular ntawm isoprene, uas yog tsim thaum roj hmab yog rhuab, nyob rau hauv nws cov khoom decomposition. Qhov kev sib tw yog nrhiav txoj hauv kev pheej yig. Thiab cov roj hmab isoprene tau txais thaum lub sij hawm cov tshuaj tiv thaiv polymerization, thiab ntawm no nws yog ib qho tseem ceeb kom raug tsim cov chav kawm ntawm cov tshuaj tiv thaiv no. Polymerization tshwm sim raws li nram no: nCH₂ =C(CH₃) - CH=CH₂ -- (-CH₂ - C(CH₃)=CH - CH_2)n.

Txoj kev pheej hmoo tshaj plaws txog tam sim no yog txoj kev ntawm catalytic dehydrogenation ntawm isopentane, uas tau tso tawm los ntawm cov roj av. Cov khoom pib rau isoprene ntau lawm kuj tuaj yeem yog pentane: CH₃-CH₂-CH₂- CH ₂-CH_{3, vim tias thaum cua sov thiab nrog cov catalysts, nws kuj hloov mus ua isopentane. Kuj tseem muaj cov txheej txheem polymerization uas cov tshuaj tiv thaiv kom tau txais cov roj hmab isoprene yog tsim los ntawm txoj kev uas cov roj hmab tau txais uas zoo sib xws hauv cov qauv rau cov roj hmab ntuj thiab, yog li ntawd, muaj cov khoom zoo tib yam.}

Isoprene

Isoprene yog ib qho tsis muaj hydrocarbon uas muaj nyob rau hauv cov koob tshuaj Diene. Nws yog cov kua tsis muaj xim tsis muaj xim. Cov ntxhiab tsw yog yam ntxwv heev. Isoprene roj hmab yog lub ntuj monomer, txij li cov seem ntawm nws cov molecule muaj nyob rau hauv ntau lwm yam ntuj sib xyaw - isoprenoids, terpenoids, thiab lwm yam. Nws dissolves hauv cov kuab tshuaj organic. Nrog ethyl cawv, piv txwv li, nws tuaj yeem sib xyaw hauv txhua qhov sib piv. Tab sis nws tsis yaj zoo hauv dej.

Tab sis nws yooj yim tsim ib chav tsev ntawm isoprene roj hmab thaum lub sij hawm polymerization, vim yog cov isoprene gutta-percha thiab rubbers tau. Tsis tas li ntawd, isoprene tuaj yeem nkag mus rau hauv ntau yam kev cuam tshuam thaum lub sijhawm copolymerization. Hauv kev lag luam, nws yog qhov tsis tseem ceeb, vim nws yog siv los ua cov roj hmab, tshuaj, thiab txawm tias qee yam tshuaj tsw qab. Hauv peb lub tebchaws, kev tsim cov roj hmab hluavtaws isoprene tau tsim los ntev, thiab suav txog kwv yees li nees nkaum plaub feem pua ntawm ntiaj teb kev tsim khoom.

History

Thawj isoprene tau txais hauv xyoo 1860 los ntawm pyrolysis los ntawm cov roj hmab ntuj.pyrolysis yog lub thermal (ntawm qhov kub siab) decomposition ntawm ntau inorganic thiab organic tebchaw nyob rau hauv tej yam kev mob ntawm tsis muaj oxygen. Tom qab ntawd, lub teeb isoprene tau tsim - ib qho hluav taws xob uas muaj lub tshuab cua sov, uas cov roj turpentine tau thermally decomposed nyob rau hauv lub chaw soj nstuam.

Tsov Rog Ntiaj Teb Zaum Ob tau coj qhov kev thov loj rau cov roj hmab isoprene, thiab yog li ntawd, isoprene tau kawm los ntawm kev lag luam los ntawm pyrolysis ntawm limonene. Txawm li cas los xij, isoprene tau kim dhau rau kev tsim khoom ntawm cov hluavtaws hluavtaws. Qhov xwm txheej tau hloov pauv thaum pom ib txoj hauv kev kom tau nws los ntawm cov roj. Tom qab ntawd cov thev naus laus zis rau polymerization ntawm isoprene pib tsim sai heev.

Role hauv kev lag luam

Qhov tseem ceeb tshaj plaws hauv kev npaj cov khoom lag luam xws li isoprene roj hmab yog qhov kev xaiv ntawm qhov chaw, vim nws yuav tsim nyog xa cov feem ntawm kev sib cais C ₅ rau lo lus uas peb los ntawm ntau lub lag luam ib zaug, uas ua rau tawg. Hauv qhov thib ob hauv qhov tseem ceeb yog qhov kev txiav txim siab hauv cov phiaj xwm rau qhov chaw pov tseg ntawm cov hydrocarbons ntxiv los ntawm C_{5. feem.}

Thaum pib ntawm cuaj caum ntawm lub xyoo pua nees nkaum, Western Europe tau tsim txog yim caum-tsib txhiab tons ntawm C_{5 tuag, ntawm plaub caug plaub txhiab tons yog dimerized cyclopentadiene thiab nees nkaum peb txhiab tons yog isoprene. Tus so - txog kaum tsib txhiab tons - yog piperylenes. Kaum xyoo tom qab, lub ntiaj teb kev tsim cov isoprene tau nce mus txog 850,000 tons hauv ib xyoos.}

Properties

Raws li tus qauv txheej txheem, isoprene, raws li twb tau hais lawm, yog cov kua tsis muaj xim tsis muaj xim, yuav luag insoluble hauv dej, tab sis miscible nyob rau hauv ib qho piv nrog diethyl cawv, tus qauv, benzene, acetone. Isoprene muaj peev xwm tsim cov azeotropic sib tov nrog ntau yam organic solvents. Thaum xav txog cov ntaub ntawv ntawm kev tshawb fawb spectroscopic, nws tuaj yeem pom tau tias twb nyob ntawm tsib caug degrees Celsius, feem ntau ntawm cov isoprene molecules coj mus rau qhov ruaj khov s-trans conformation, tsuas yog kaum tsib feem pua ntawm cov molecules nyob rau hauv s-cis conformation. Ntawm cov xeev no, lub zog sib txawv yog 6.3 kJ.

Cov khoom siv tshuaj lom neeg ntawm isoprene tam sim no nws yog ib qho kev sib txuas ua ke, uas nkag mus rau hauv kev hloov pauv, ntxiv, complexation, cyclization, telomerization cov tshuaj tiv thaiv. Active nyob rau hauv cov tshuaj tiv thaiv nrog electrophiles thiab dienophiles.

Daim ntawv thov

Qhov tseem ceeb ntawm isoprene tam sim no tsim tau siv rau hauv kev sib txuas ntawm isoprene roj hmab, zoo ib yam hauv cov qauv thiab cov khoom rau cov roj hmab ntuj. Nws yog siv tshwj xeeb tshaj yog dav rau kev tsim cov log tsheb. Kuj tseem muaj lwm cov khoom lag luam isoprene polymerization, polyisoprene, uas yog siv tsawg dua vim nws muaj cov khoom ntawm gutta-percha. Nws yog siv los ua hlau rwb thaiv tsev thiab golf pob, piv txwv li. Isoprene roj hmab yog siv los ua txhua yam ntawm cov khoom siv roj hmab uas sib xyaw ua ke ntawm ntuj thiab lwm yam roj hmab hluavtaws.

Piv txwv li, txhawm rau txo qhov nplaum, ntxivbutadiene-methylstyrene rubbers, ntxiv rau, qaug zog endurance nce yog tias cov deformations rov qab. Nitrites ntxiv ozone tsis kam thiab tiv thaiv kev laus thaum tshav kub kub. Yog li, soj ntsuam cov txheej txheem ntawm cov khoom siv, cov roj hmab isoprene zoo kawg nkaus ua rau lawv tus kheej thaum siv cov hlua khi, nqus los yog lub siab hoses, thaum siv lub tshuab shafts, hauv kev tsim cov khau, kho mob thiab lwm yam khoom.

Environmental hazard

Isoprene yog qhov tawg thiab tawg heev. Nyob rau hauv siab concentrations nyob rau hauv lub cev, nws yuav ua rau tuag tes tuag taw. Qhov no feem ntau tshwm sim ntawm atmospheric saturation, thiab yog li ntawd metabolism tshwm sim nyob rau hauv lub ua pa system, thaum isoprene hloov mus rau epoxides thiab diols.

Plaub caug milligrams ib lub cubic meter yog suav tias yog qhov siab siab - qhov no yog qhov siab tshaj plaws. Me me ntawm isoprene nyob rau hauv cov huab cua tuaj yeem ua rau muaj kev phom sij rau tib neeg, ua rau khaus ntawm lub qhov muag, tawv nqaij, ua pa thiab cov mucous membranes.

Biology

Cov kws tshawb fawb niaj hnub tau tshawb pom tias cov pa isoprene tawm yuav luag txhua cov nroj tsuag rau hauv qhov chaw. Lub ntiaj teb tus nqi ntawm phytogenic isoprene yog kwv yees li ntawm (180-450)^.10 12 carbon ib xyoos twg. Cov txheej txheem no tau nrawm dua yog tias huab cua kub nce mus txog peb caug degrees Celsius, thiab yog tias qhov kev siv ntawm lub hnub ci hluav taws xob yog siab, thaum photosynthesis twb tag nrho saturated. Isoprene biosynthesis inhibited los ntawm fosmidomycin thiab cov tebchaw ntawm tag nrhoib tug xov tooj ntawm statins. Vim li cas cov nroj tsuag ua qhov no tsis nkag siab tag nrho. Tej zaum cov isoprene muab lawv ntxiv rau kev tiv thaiv overheating. Tsis tas li ntawd, nws yog ib qho radical scavenger, uas txhais tau tias nws tuaj yeem tiv thaiv cov nroj tsuag los ntawm cov pa oxygen reactive thiab ozone.

Cov kws tshawb fawb tseem qhia tias kev sib txuas ntawm isoprene ua rau kev noj tas li ntawm NADPH thiab ATP molecules, uas cov nroj tsuag tsim thaum lub sijhawm photosynthesis. Li no, kev tso tawm ntawm isoprene tiv thaiv cov duab-oxidative degradation thiab rov txo qis yog tias lub teeb pom kev ntau dhau. Qhov tsis zoo ntawm cov txheej txheem tiv thaiv no yuav yog ib qho: cov pa roj carbon, uas tau muab rho tawm nrog qhov nyuaj ntawm cov txheej txheem ntawm photosynthesis, yog siv rau kev tso tawm ntawm isoprene. Cov kws tshawb fawb tsis tau nres ntawm cov nroj tsuag thiab pom tias tib neeg lub cev tuaj yeem tsim cov hydrocarbons diene, thiab isoprene yog qhov ntau tshaj ntawm lawv.