Cov khoom siv organic nyob hauv qhov chaw tseem ceeb hauv peb lub neej. Lawv yog cov khoom tseem ceeb ntawm cov polymers uas nyob ib puag ncig peb txhua qhov chaw: cov no yog cov hnab yas, thiab roj hmab, nrog rau ntau yam khoom siv. Polypropylene tsis yog kauj ruam kawg hauv cov koob no. Nws kuj pom muaj nyob rau hauv ntau yam ntaub ntawv thiab yog siv nyob rau hauv ib tug xov tooj ntawm industries xws li kev tsim kho, domestic siv raws li ib tug khoom rau lub khob yas, thiab lwm yam me me (tab sis tsis industrial scale) xav tau. Ua ntej peb tham txog cov txheej txheem xws li hydration ntawm propylene (ua tsaug uas, los ntawm txoj kev, peb tuaj yeem tau txais isopropyl cawv), cia peb tig mus rau keeb kwm ntawm kev tshawb pom ntawm cov tshuaj no tsim nyog rau kev lag luam.
History
Li ntawd, propylene tsis muaj hnub qhib. Txawm li cas los xij, nws cov polymer - polypropylene - tau pom tiag tiag hauv xyoo 1936 los ntawm tus kws tshuaj German nto moo Otto Bayer. Tau kawg, nws tau paub theoretical paub tias cov khoom tseem ceeb li cas tuaj yeem tau txais, tab sis nws tsis tuaj yeem ua qhov no hauv kev xyaum. Qhov no tsuas yog ua tau nyob rau hauv nruab nrab ntawm lub xyoo pua nees nkaum, thaum German thiab Italian chemists Ziegler thiab Natt nrhiav tau ib tug catalyst rau lub polymerization ntawm unsaturated hydrocarbons (muaj ib los yog ntau tshaj ntau daim ntawv cog lus), uas. Tom qab ntawd lawv hu ua Ziegler-Natta catalyst. Txog rau lub sijhawm ntawd, nws tsis tuaj yeem ua kom cov tshuaj tiv thaiv polymerization ntawm cov tshuaj no ua tiav. Cov tshuaj tiv thaiv polycondensation tau paub, thaum, yam tsis muaj qhov cuam tshuam ntawm catalyst, cov tshuaj tau muab tso rau hauv cov saw hlau polymer, tsim los ntawm cov khoom lag luam. Tab sis nws tsis tuaj yeem ua qhov no nrog unsaturated hydrocarbons.
Lwm cov txheej txheem tseem ceeb cuam tshuam nrog cov tshuaj no yog nws cov dej. Propylene nyob rau hauv lub xyoo pib ntawm nws siv yog heev heev. Thiab tag nrho cov no yog vim cov txheej txheem ntawm kev rov qab propene tsim los ntawm ntau lub tuam txhab roj thiab roj ua haujlwm (qhov no qee zaum kuj hu ua cov khoom piav qhia). Thaum cov roj tawg, nws yog cov khoom lag luam, thiab thaum nws muab tawm tias nws cov derivative, isopropyl cawv, yog lub hauv paus rau kev sib txuas ntawm ntau yam khoom muaj txiaj ntsig rau noob neej, ntau lub tuam txhab, xws li BASF, patented lawv txoj kev tsim nws. thiab pib loj trading lub compound no. Propylene hydration tau sim thiab siv ua ntej polymerization, uas yog vim li cas acetone, hydrogen peroxide, isopropylamine pib tsim ua ntej polypropylene.
txheej txheem ntawm kev sib cais propene los ntawm cov roj yog qhov nthuav heev. Nws yog rau nws tam sim no peb tig.
Sib cais ntawm propylene
Qhov tseeb, hauv kev nkag siab theoretical, txoj hauv kev tseem ceeb tsuas yog ib qho txheej txheem: pyrolysis ntawm cov roj thiab cov roj sib txuas. Tab sis kev siv thev naus laus zis tsuas yog dej hiav txwv xwb. Qhov tseeb yog tias txhua lub tuam txhab sib zog ua kom tau ib txoj hauv kev tshwj xeeb thiab tiv thaiv nws.patent, thiab lwm lub tuam txhab xws li tseem tab tom nrhiav rau lawv tus kheej txoj hauv kev tseem tsim thiab muag propene ua raw khoom lossis tig mus rau ntau yam khoom.
Pyrolysis ("pyro" - hluav taws, "lysis" - kev puas tsuaj) yog cov txheej txheem tshuaj ntawm kev rhuav tshem cov molecule complex thiab loj rau hauv cov me me nyob rau hauv lub siab kub thiab catalyst. Roj, raws li koj paub, yog ib tug sib tov ntawm hydrocarbons thiab muaj lub teeb, nruab nrab thiab hnyav feem. Ntawm thawj, qhov qis tshaj qhov hnyav molecular, propene thiab ethane tau txais thaum lub sij hawm pyrolysis. Cov txheej txheem no yog nqa tawm hauv qhov cub tshwj xeeb. Rau cov tuam txhab tsim khoom siab tshaj plaws, cov txheej txheem no yog qhov sib txawv ntawm kev siv tshuab: qee qhov siv xuab zeb ua cov khoom siv hluav taws xob, lwm tus siv quartz, lwm tus siv coke; Koj tuaj yeem faib cov furnaces raws li lawv cov qauv: muaj tubular thiab cov pa, raws li lawv hu ua, reactors.
Tab sis cov txheej txheem pyrolysis ua rau kom tau txais cov propene tsis txaus, vim tias, ntxiv rau nws, ntau cov hydrocarbons tau tsim nyob rau ntawd, uas tom qab ntawd yuav tsum tau muab cais ua ntau txoj hauv kev siv zog. Yog li ntawd, kom tau txais cov tshuaj ntshiab rau cov dej tom qab, dehydrogenation ntawm alkanes kuj tseem siv: hauv peb rooj plaub, propane. Ib yam li polymerization, cov txheej txheem saum toj no tsis yog tshwm sim xwb. Kev sib cais ntawm hydrogen los ntawm cov molecule ntawm ib tug saturated hydrocarbon tshwm sim nyob rau hauv qhov kev txiav txim ntawm catalysts: trivalent chromium oxide thiab txhuas oxide.
Zoo, ua ntej yuav mus rau zaj dab neeg ntawm yuav ua li cas cov txheej txheem hydration tshwm sim, cia peb tig mus rau cov qauv ntawm peb cov hydrocarbon unsaturated.
Cov qauv ntawm propylene
Propene nws tus kheej tsuas yog tus tswv cuab thib ob ntawm alkene series (hydrocarbons nrog ib daim ntawv cog lus ob npaug). Nyob rau hauv cov nqe lus ntawm lightness, nws tsuas yog thib ob rau ethylene (los ntawm uas, raws li koj yuav twv, polyethylene yog tsim - lub polymer loj tshaj plaws nyob rau hauv lub ntiaj teb no). Hauv nws lub xeev ib txwm, propene yog roj, zoo li nws "kwv tij" los ntawm tsev neeg alkane, propane.
Tab sis qhov sib txawv tseem ceeb ntawm propane thiab propene yog qhov tom kawg muaj ob daim ntawv cog lus hauv nws cov muaj pes tsawg leeg, uas hloov pauv nws cov tshuaj lom neeg. Nws tso cai rau koj los txuas lwm yam khoom rau ib qho tsis muaj hydrocarbon molecule, uas ua rau cov tebchaw nrog cov khoom sib txawv, feem ntau tseem ceeb heev rau kev lag luam thiab lub neej txhua hnub.
Nws yog lub sijhawm los tham txog kev xav tshuaj tiv thaiv, uas, qhov tseeb, yog cov ntsiab lus ntawm tsab xov xwm no. Hauv seem tom ntej no, koj yuav kawm paub tias hydration ntawm propylene tsim ib qho ntawm cov khoom lag luam tseem ceeb tshaj plaws, nrog rau cov tshuaj tiv thaiv no tshwm sim thiab dab tsi yog qhov nuances hauv nws.
Hydration Theory
Ua ntej, cia peb tig mus rau cov txheej txheem dav dav - kev daws teeb meem - uas kuj suav nrog cov tshuaj tiv thaiv tau piav qhia saum toj no. Qhov no yog ib qho tshuaj hloov pauv, uas muaj nyob rau hauv qhov sib ntxiv ntawm cov kuab tshuaj molecules rau solute molecules. Nyob rau tib lub sijhawm, lawv tuaj yeem tsim cov molecules tshiab, lossis hu ua solvates, cov khoom uas muaj cov molecules ntawm cov kuab tshuaj thiab cov kuab tshuaj txuas nrog electrostatic kev sib cuam tshuam. Peb tsuas yog txaus siab xwbthawj hom tshuaj, vim hais tias thaum lub sij hawm hydration ntawm propylene, xws li cov khoom yog feem ntau tsim.
Thaum daws raws li tau piav qhia saum toj no, cov kuab tshuaj molecules txuas nrog rau cov kuab tshuaj, tau txais cov tshuaj tshiab. Hauv cov organic chemistry, hydration feem ntau tsim cov cawv, ketones, thiab aldehydes, tab sis muaj ob peb lwm yam, xws li tsim glycols, tab sis peb yuav tsis kov lawv. Qhov tseeb, cov txheej txheem no yooj yim heev, tab sis tib lub sijhawm nyuaj heev.
Hydration mechanism
Ob daim ntawv cog lus, raws li koj paub, muaj ob hom kev sib txuas ntawm atoms: pi- thiab sigma-bonds. Lub pi-bond yeej ib txwm yog thawj zaug tawg thaum lub sij hawm hydration cov tshuaj tiv thaiv, vim nws tsis tshua muaj zog (nws muaj lub zog khi qis dua). Thaum nws tawg, ob qhov chaw tsis muaj qhov chaw nyob yog tsim los ntawm ob lub atoms nyob sib ze, uas tuaj yeem tsim cov ntawv cog lus tshiab. Cov dej molecule uas muaj nyob rau hauv cov tshuaj nyob rau hauv daim ntawv ntawm ob particles: ib tug hydroxide ion thiab ib tug proton, muaj peev xwm mus koom nrog ib tug tawg ob daim ntawv cog lus. Hauv qhov no, hydroxide ion txuas nrog lub hauv paus carbon atom, thiab cov proton - mus rau qhov thib ob, huab. Yog li, thaum lub sij hawm hydration ntawm propylene, propanol 1, los yog isopropyl cawv, feem ntau tsim. Qhov no yog ib qho tseem ceeb heev, txij li thaum nws yog oxidized, acetone tau txais, uas yog dav siv nyob rau hauv peb lub ntiaj teb no. Peb hais tias nws yog tsim feem ntau, tab sis qhov no tsis yog tag nrho. Kuv yuav tsum hais qhov no: tib yam khoom tsim thaum lub sij hawm hydration ntawm propylene, thiab qhov no yog isopropyl cawv.
Qhov no yog, ntawm chav kawm, tag nrho cov subtleties. Qhov tseeb, txhua yam tuaj yeem piav tau yooj yim dua. Thiab tam sim no peb yuav pom tias yuav ua li cas cov txheej txheem xws li propylene hydration raug kaw hauv tsev kawm ntawv chav kawm.
Reaction: cas nws tshwm sim
Nyob hauv chemistry, txhua yam feem ntau txhais tau yooj yim: nrog kev pab ntawm kev sib npaug sib npaug. Yog li kev hloov tshuaj lom neeg ntawm cov tshuaj nyob rau hauv kev sib tham tuaj yeem piav qhia li no. Lub hydration ntawm propylene, uas nws cov tshuaj tiv thaiv kab zauv yog yooj yim heev, ua nyob rau hauv ob theem. Ua ntej, daim ntawv cog lus pi, uas yog ib feem ntawm ob, tawg. Tom qab ntawd cov dej molecule nyob rau hauv daim ntawv ntawm ob hais, ib tug hydroxide anion thiab ib tug hydrogen cation, mus rau lub propylene molecule, uas tam sim no muaj ob qhov chaw tsis muaj nyob rau hauv lub tsim ntawm bonds. Cov hydroxide ion tsim ib daim ntawv cog lus nrog tsawg hydrogenated carbon atom (uas yog, nrog rau qhov uas tsawg dua hydrogen atoms txuas), thiab cov proton, feem, nrog rau qhov tseem ceeb heev. Yog li, ib qho khoom lag luam tau txais: saturated monohydric cawv isopropanol.
Yuav sau cov lus teb li cas?
Tam sim no peb yuav kawm yuav ua li cas sau cov lus tshuaj lom neeg cov tshuaj tiv thaiv uas cuam tshuam txog cov txheej txheem xws li hydration ntawm propylene. Cov mis peb xav tau yog: CH2 =CH - CH3. Qhov no yog cov qauv ntawm cov khoom qub - propene. Raws li koj tuaj yeem pom, nws muaj ob daim ntawv cog lus, cim nrog "=", thiab qhov no yog qhov chaw dej yuav ntxiv thaum cov propylene hydrated. Cov kev sib npaug sib npaug tuaj yeem sau tau zoo li no: CH2 =CH - CH3 + H2O=CH 3 - CH(OH) - CH3. Cov pab pawg hydroxyl nyob rau hauv brackets txhais tau tiashais tias qhov no tsis yog nyob rau hauv lub dav hlau ntawm lub mis, tab sis hauv qab no los yog saum toj no. Ntawm no peb tsis tuaj yeem qhia cov ces kaum ntawm peb pawg txuas los ntawm nruab nrab carbon atom, tab sis cia peb hais tias lawv kwv yees li sib npaug ntawm ib leeg thiab ua rau 120 degrees.
Nws thov nyob qhov twg?
Peb twb tau hais tias cov tshuaj tau txais thaum lub sijhawm cov tshuaj tiv thaiv yog nquag siv rau kev sib txuas ntawm lwm yam tseem ceeb. Nws yog qhov zoo sib xws hauv cov qauv rau acetone, los ntawm qhov sib txawv tsuas yog nyob rau hauv uas tsis yog ib pawg hydroxo muaj ib pawg keto (uas yog, cov pa oxygen atom txuas los ntawm ob daim ntawv cog lus rau nitrogen atom). Raws li koj paub, acetone nws tus kheej yog siv rau hauv cov kuab tshuaj thiab cov kua roj vanish, tab sis, ntxiv rau, nws yog siv los ua ib qho reagent rau kev sib txuas ntxiv ntawm ntau cov tshuaj, xws li polyurethanes, epoxy resins, acetic anhydride, thiab lwm yam.
Acetone ntau lawm cov tshuaj tiv thaiv
Peb xav tias nws yuav muaj txiaj ntsig los piav qhia txog kev hloov pauv ntawm isopropyl cawv rau hauv acetone, tshwj xeeb tshaj yog vim tias qhov tshuaj tiv thaiv no tsis nyuaj. Yuav pib nrog, propanol yog evaporated thiab oxidized nrog oxygen ntawm 400-600 degrees Celsius ntawm ib tug tshwj xeeb catalyst. Cov khoom ntshiab heev tau txais los ntawm kev ua cov tshuaj tiv thaiv ntawm cov nyiaj mesh.
Reaction equation
Peb yuav tsis nkag mus rau hauv cov ntsiab lus ntawm cov txheej txheem ntawm cov tshuaj tiv thaiv oxidation ntawm propanol rau acetone, vim nws nyuaj heev. Peb txwv peb tus kheej mus rau qhov kev sib hloov tshuaj ib txwm muaj: CH3 - CH(OH) - CH3 + O2=CH3 - C(O) - CH3 +H2O. Raws li koj tuaj yeem pom, txhua yam yooj yim heev ntawm daim duab, tab sis nws tsim nyog delving rau hauv cov txheej txheem, thiab peb yuav ntsib ntau yam teeb meem.
Zoo kawg
Yog li peb tau txheeb xyuas cov txheej txheem ntawm propylene hydration thiab kawm txog qhov sib npaug ntawm cov tshuaj tiv thaiv thiab cov txheej txheem ntawm nws qhov tshwm sim. Cov txheej txheem thev naus laus zis suav hais tias yog cov txheej txheem tiag tiag tshwm sim hauv kev tsim khoom. Raws li qhov tshwm sim, lawv tsis nyuaj, tab sis lawv muaj txiaj ntsig tiag tiag rau peb lub neej txhua hnub.
