Co ntawm propylene: kab zauv cov tshuaj tiv thaiv

Organic tshuaj muaj ib qho tseem ceeb qhov chaw nyob rau hauv peb lub neej. Lawv yog cov tseem ceeb tivthaiv polymers uas yog tag nrho cov nyob ib ncig ntawm peb: nws yog hnab yas, thiab roj hmab, raws li zoo raws li ntau lwm yam ntaub ntawv. Polypropylene npog nyob rau hauv no series yog tsis kawg kauj ruam. Nws kuj muaj nyob rau hauv ntau yam ntaub ntawv thiab yog siv nyob rau hauv ntau industries xws li siv, ib lub tsev siv raws li ib tug cov ntaub ntawv uas rau yas khob thiab lwm yam me me (tab sis tsis nyob rau scale lawm) xav tau kev pab. Ua ntej peb yuav tham txog xws li ib tug txheej txheem, raws li cov co ntawm propylene (los ntawm cov uas, los ntawm txoj kev, peb yuav tau txais isopropyl cawv), saib cov keeb kwm ntawm lub foundations ntawm no tseem ceeb tshuaj rau qhov kev lag luam.

zaj dabneeg

Raws li xws li, cov lus qhib hnub ntawm lub propylene tsis. Txawm li cas los, nws polymer - Polypropylene -was ua tau qhib nyob rau hauv 1936 los ntawm lub npe nrov German chemist Otto Bayer. Ntawm cov hoob kawm, raws, nws twb paub raws li ib tug yuav tau txais xws ib qho tseem ceeb teeb meem, tab sis nyob rau hauv kev xyaum no yog tsis muaj kev vam meej. Nws ua tau zoo xwb nyob rau hauv nruab nrab-thib nees nkaum xyoo pua qhia thaum German thiab Italian chemists thiab Ziegler Nutt qhib unsaturated hydrocarbon polymerisation catalyst (muaj ib tug los yog ntau tshaj ob npaug rau bonds), uas yog tom qab thiab muaj npe: Ziegler-Natta catalysts. Mus txog no nws yog kiag li tsis yooj yim sua kom ua tau cov polymerization cov tshuaj tiv thaiv ntawm tej tshuaj tau ploj mus. Lawv twb paub polycondensation cov tshuaj tiv thaiv, thaum lub catalyst tsis muaj cuam tshuam rau yam khoom uas kev cob cog rua rau lub polymer saw, li no txoj kev ua by-khoom. Tab sis, nrog unsaturated hydrocarbons tsis tau zoo.

Ib qho tseem ceeb cov txheej txheem uas txuam nrog no yeeb tshuaj, yog nws co. Propylene thaum lub sij hawm pib ntawm nws siv yog ib tug heev heev. Thiab tag nrho cov no ua tsaug rau cov yees ntau yam roj thiab cov nkev ua tuam txhab uas muag ib tug kho propene (tej thaum kuj raug xa mus rau raws li ib yam khoom uas tau piav). Lub cracking ntawm crude roj yog ib tug los ntawm-cov khoom, thiab thaum twg nws muab tawm hais tias ib tug derivative thereof, isopropyl cawv, yog lub hauv paus rau lub synthesis ntawm ntau pab tshuaj rau noob neej, muaj ntau yam tuam txhab uas muag, xws li ntawm BASF, patented lawv txoj kev ntau lawm thiab launched ib tug loj heev luam nyob rau hauv no kev twb kev txuas. Propylene Co tau kuaj thiab thov ua ntej polymerization yog vim li cas acetone, hydrogen peroxide, isopropylamine pib ua ntej yuav tsim polypropylene.

Ib tug heev nthuav cov txheej txheem ntawm kev sib cais ntawm propene los ntawm roj av. Nws yog rau nws peb tam sim no tig.

Rho tawm ntawm propylene

Ua tau, nyob rau hauv ib tug theoretical kev nkag siab ntawm qhov yooj yim txoj kev yog mus tsuas yog ib qho txheej txheem: pyrolysis roj thiab txuam roj cua. Tab sis tam sim no technology implementations - cia li ib lub hiav txwv. Qhov tseeb yog hais tias txhua txhua lub tuam txhab nrhiav kom tau ib tug tshwj xeeb txoj kev thiab tiv thaiv nws cov patent thiab lwm yam zoo xws tuam txhab uas muag tseem tab tom nrhiav rau lawv tus kheej txoj kev los tseem ua thiab muag propene li raw khoom los yog tig nws mus rau hauv ib tug ntau yam ntawm cov khoom.

Pyrolysis ( "Pyro" - hluav taws "lys" - puas tsuaj) - tshuaj lwj txheej txheem nyuab thiab loj molecules mus rau hauv me me uas sawv daws yuav nyob rau hauv tus ntawm kub thiab catalyst. Roj, raws li yog lub npe hu, yog ib tug sib tov ntawm hydrocarbons muaj teeb, medium thiab hnyav fractions. Los ntawm cov thawj, cov tsawg heev molecular luj, thiab yog propene thiab ethane nyob rau hauv lub pyrolysis. Qhov no txoj kev yog nqa tawm nyob rau hauv tshwj xeeb furnaces. Nyob rau hauv lub siab heev tshaj plaws manufacturers ntawm cov txheej txheem technology yog sib txawv: ib co xuab zeb yog siv raws li ib tug coolant, rau lwm yam - quartz, thiab lwm leej lwm tus - coke; Koj muaj peev xwm kuj tau faib cov qhov cub nyob rau hauv lawv cov qauv: muaj tubular thiab cov pa, raws li lawv yog hu ua reactors.

Tab sis lub pyrolysis txheej txheem ua txaus huv prop, raws li, sib nrug los ntawm nws, muaj yog tsim ib tug myriad ntawm hydrocarbons, uas ces yuav tau faib haum zog-intensive txoj kev. Yog li ntawd, mus nrhiav tau ib tug dawb huv cov ntaub ntawv uas raws li siv rau lub dehydrogenation ntawm alkanes ua raws li los ntawm co: nyob rau hauv peb cov ntaub ntawv - hluav taws roj zeb. Raws li zoo raws li lub polymerization txheej txheem tau piav saum toj no cia li tsis tshwm sim. Cleavage los ntawm hydrogen molkuly limiting hydrocarbon tshwm sim nyob rau hauv qhov kev txiav txim ntawm catalysts ntawm trivalent chromium oxide thiab txhuas oxide.

Tab sis ua ntej uas koj mus rau zaj dab neeg ntawm yuav ua li cas lub co txheej txheem, saib cov qauv ntawm peb unsaturated hydrocarbons.

Tshwj xeeb tshaj yog propylene qauv

Propen nws tus kheej - tsuas yog tus thib ob tug tswv cuab ntawm ib tug xov tooj ntawm alkenes (hydrocarbons nrog ib tug muab ob npaug rau daim ntawv cog lus). Rau yooj yim, nws yog zaum ob tsuas yog mus ethylene (los ntawm uas, raws li tej zaum koj yuav twv, ua polyethylene - lub polymer hnyav nyob rau hauv lub ntiaj teb no). Nyob rau hauv lub qub xeev propen - gas raws li nws cov "txheeb ze" ntawm tsev neeg ntawm alkanes, hluav taws roj zeb.

Tab sis ib tug tseem ceeb sib txawv hluav taws roj zeb los ntawm propene - yog hais tias lub caij nyoog kawg no muaj nyob rau hauv nws cov muaj pes tsawg leeg ib tug muab ob npaug rau daim ntawv cog lus, uas radically hloov nws tshuaj zog. Nws tso cai rau kev twb kev txuas mus rau ib tug qauv ntawm unsaturated hydrocarbon lwm yam, uas ib tug compound tau nrog sib txawv kiag li cov khoom no feem ntau yog qho tseem ceeb heev rau kev lag luam thiab tsev neeg.

Nws yog lub sij hawm los tham txog cov tshuaj tiv thaiv kev tshawb xav, uas, nyob rau hauv qhov tseeb, qhov kev kawm ntawm no tsab xov xwm. Nyob rau hauv lub tom ntej no seem, koj yuav kawm tau hais tias tsim nyob rau ib qho ntawm feem muag ib qho tseem ceeb cov khoom, thiab ua li cas qhov no cov tshuaj tiv thaiv thiab dab tsi yog qhov nuances nyob rau hauv nws thaum propylene co.

Qhov kev tshawb xav ntawm co

Yuav pib, cia peb tig mus rau ib tug ntau dav txheej txheem - solvation - uas muaj xws li kuj yog cov saum toj no piav cov tshuaj tiv thaiv. Qhov no tshuaj hloov dua siab tshiab, uas muaj nyob rau hauv pub ntxiv tshaj qhov kuab molecules mus rau lub lwg me me ntawm lub solute. Yog li lawv yuav tsim ib tug tshiab qauv, los yog qhov thiaj li hu ua solvates, - hais muaj lub solute molecules thiab kuab yam electrostatic sis raug zoo. Peb xav nyob rau hauv tsuas yog tus thawj hom ntawm cov ntaub ntawv, vim hais tias thaum cov co ntawm propylene yog dua li tsim xws khoom.

Nyob rau hauv lub saum toj no txoj kev solvation kuab molecules uas txuas mus rau lub solute, tau tshiab compound. Nyob rau hauv cov organic Science News for KIDS advantageously tsim thaum lub sij hawm co alcohols, ketones thiab aldehydes, tab sis muaj ib co lwm yam mob, xws li cov tsim ntawm glycols, tab sis lawv yuav tsis txhob tham txog. Nyob rau hauv qhov tseeb, txoj kev no yog yooj yim heev, tab sis nyob rau tib lub sij hawm yog heev tham.

co mechanism

Ob chav daim ntawv cog lus, raws li yog lub npe hu, muaj ob hom ntawm atomic bonds: pi thiab sigma bonds. Pi-daim ntawv cog lus lawm thaum co yeej ib txwm thawj cov tshuaj tiv thaiv, raws li nws yog tsawg zog (muaj ib tug me me losis tswvyim dabtsi zog). Thaum nws rupture ntaub ntawv ob tug tsis muaj orbitals ntawm ob uas nyob ib sab carbon atoms uas tej zaum yuav tsim tshiab bonds. Ib tug dej molecule uas tau tshwm sim nyob rau hauv cov tshuaj nyob rau hauv daim ntawv ntawm ob hais ntawm hydroxide ion thiab proton, muaj peev xwm koom nrog pob tawg lawm muab ob npaug rau daim ntawv cog lus. Wherein lub hydroxide ion yog txuas mus rau lub hauv paus carbon atom thiab lub proton - mus rau lub thib ob extreme. Yog li, nyob rau hauv cov co ntawm propylene yog tsim feem ntau 1-propanol, los yog isopropyl haus dej cawv. Qhov no yog ib qho tseem ceeb heev teeb meem, vim nws yog tau mus nrhiav tau oxidation ntawm acetone, siv nyob rau hauv loj qhov ntau nyob rau hauv peb lub ntiaj teb. Peb hais tias nws yog tsim feem ntau, tab sis qhov no yog tsis muaj tseeb. Kuv yuav tsum hais li no: tus xwb khoom tsim los ntawm co ntawm propylene, thiab qhov no - isopropyl haus dej cawv.

Qhov no, ntawm chav kawm, tag nrho cov subtleties. Nyob rau hauv qhov tseeb, txhua yam yuav ua tau yooj yim npaum li mus piav qhia txog. Thiab tam sim no peb paub yuav ua li cas sau ntawv ib lub tsev kawm ntawv chav kawm ntawm ib tug txheej txheem xws li cov co ntawm propylene.

Cov tshuaj tiv thaiv: yuav ua li cas nws tshwm sim

Nyob rau hauv Science News for KIDS rau denote txhua yam yog yooj yim: nrog kev pab los ntawm cov tshuaj tiv thaiv kab zauv. Uas tshuaj pom ntawm qhov teeb meem nyob rau hauv kev sib tham yuav tau piav li no. Co ntawm propylene, cov tshuaj tiv thaiv kab zauv yog heev yooj yooj yim thiab yuav siv sij hawm qhov chaw nyob rau hauv ob ua sawv. Thawj coj thiab ua tus pi-daim ntawv cog lus, ib feem ntawm ib tug muab ob npaug rau. Ces tus dej molecule nyob rau hauv daim ntawv ntawm ob hais ntawm hydroxide anion thiab hydrogen ntawv, haum rau propylene molecule muaj active lub sij hawm ntawm ob tsis muaj rooj zaum tsim bonds. Hydroxide ion ntaub ntawv ib tug daim ntawv cog lus nrog cov pa roj carbon atom tsawg hydrogenated (i.e. nrog, uas ib tug tsawg heev npaum li cas ntawm hydrogen atoms), thiab ib tug proton, ntsig txog, - nrog rau seem uas extreme. Yog li, muaj ib zaug xwb khoom ntawm: limiting lub monohydric cawv yog isopropanol.

Yuav ua li cas sau ib lo lus teb?

Tam sim no peb yuav kawm tau li cas los sau cov lus uas cov tshuaj cov tshuaj tiv thaiv, reflecting ib tug txheej txheem xws li cov co ntawm propylene. Ib tug mis uas yog pab tau rau peb: CH ₂ = CH - CH _3. Qhov no yog cov mis ntawm lub starting khoom - propene. Raws li koj tau pom, nws muaj ib tug muab ob npaug rau daim ntawv cog lus yog qhia los ntawm tus kos npe rau "=", thiab nyob rau hauv qhov chaw no yuav prisoednyatsya dej thaum lub co ntawm propylene yuav tshwm sim. Cov tshuaj tiv thaiv kab zauv yuav sau li: CH ₂ = CH - CH ₃ + H ₂ O = CH ₃ - CH (OH) - CH _3. Lub hydroxyl pab pawg neeg nyob rau hauv lub parenthesis txhais tau tias qhov no yog ib feem tsis yog nyob rau hauv lub dav hlau ntawm lub mis, thiab hauv qab no los yog saum toj no. Ntawm no yog peb yuav tsis qhia lub ces kaum ntawm lub peb pawg neeg, extending los ntawm nruab nrab carbon atom, tab sis hais tias lawv yog kwv yees li sib npaug zos rau txhua lwm yam thiab ua mus txog 120 degrees.

Qhov twg yog nws siv?

Peb twb hais tias tau nyob rau hauv lub chav kawm ntawm cov tshuaj tiv thaiv yam khoom uas yog lug siv rau kev synthesis ntawm lwm yam tseem ceeb heev tshuaj rau peb. Nws yog ib heev zoo xws li cov nyob rau hauv cov qauv rau acetone, los ntawm uas nws txawv tsuas nyob rau hauv uas tsis teev muaj gidroksogrupp keto (ie, oxygen atom kev cob cog rua ntawm ib tug muab ob npaug rau daim ntawv cog lus mus rau ib tug nitrogen atom). Raws li yog lub npe hu, acetone nws tus kheej yog siv nyob rau hauv varnishes thiab kuab tshuaj, tab sis nyob rau hauv tas li ntawd, nws yog siv raws li ib tug reactant rau ntxiv synthesis ntawm ntau yam xws li polyurethanes, epoxy cob, acetic anhydride , thiab hais txog.

acetone ua cov tshuaj tiv thaiv

Peb xav tias nws yog pab tau rau piav qhia txog lub transformation ntawm isopropyl cawv, acetone, tshwj xeeb tshaj yog vim qhov no cov tshuaj tiv thaiv yog tsis yog li ntawd tham. Yuav pib, propanol thiab evaporated rau ntawm 400-600 degrees Celsius oksilyayut oxygen ntawm ib tug tshwj xeeb catalyst. Ib tug heev ntshiab khoom yog tau los ntawm nqa tawm cov tshuaj tiv thaiv nyob rau hauv ib tug silver mesh.

cov tshuaj tiv thaiv kab zauv

Peb yuav tsis mus rau hauv cov ntsiab lus ntawm cov tshuaj tiv thaiv mechanism rau lub oxidation ntawm propanol nyob rau hauv acetone vim nws yog heev complex. Kaw pa tshuaj hloov dua siab tshiab equation: CH ₃ - CH (OH) - CH ₃ + O ₂ = CH ₃ - C (O) - CH ₃ + H ₂ O. li pom nyob rau hauv Scheme tag nrho cov heev yooj yim, tab sis nws yog tsim nyog los mus ntxaum mus rau hauv cov txheej txheem, thiab peb yuav fim ib tug xov tooj ntawm cov teeb meem.

xaus

Yog li ntawd peb rhuav lub propylene co txheej txheem thiab cov kab zauv rau cov tshuaj tiv thaiv kawm thiab lub mechanism ntawm nws tshwm sim. Xam tias yog hauj ntsiab cai yog lub hauv paus ntawm lub sij dab noj qhov chaw nyob rau hauv lub lag luam. Raws li nws muab tawm, lawv yog tsis heev, tab sis muaj ib tug tiag tiag kev pab rau peb cov uas niaj hnub lub neej.