Kev Ntxiv Polymerization: Txoj Cai, Daim Ntawv Thov, thiab Cov Txiaj Ntsig hauv Kev Lag Luam
Pendahuluuan
Kev ua polymerization yog ib qho tshuaj lom neeg uas cov molecule monomer me me sib xyaw ua ke los ua cov macromolecules loj uas hu ua polymers. Ib qho ntawm cov hom polymerization feem ntau yog kev ntxiv polymerization. Tsab xov xwm no lub hom phiaj yog piav qhia txog cov txheej txheem yooj yim ntawm kev ntxiv polymerization, nws ntau yam kev siv hauv kev lag luam tseem ceeb, thiab cov txiaj ntsig uas nws muaj.
Kev Sib Ntxiv Polymerization Mechanism
Kev sib ntxiv polymerization, tseem hu ua saw polymerization, yog ib qho txheej txheem uas cov monomers nrog ob chav bonds lossis reactive functional pawg sib xyaw ua ke los ntawm ntau qhov kev sib ntxiv reactions los tsim ib tug polymer. Cov txheej txheem no muaj peev xwm muab faib ua peb theem tseem ceeb: pib, nthuav dav, thiab xaus.
1. Kev pib
Kev pib yog theem pib ntawm polymerization uas cov free radicals lossis ions raug tsim los ua cov hom tshuaj reactive. Cov free radicals no feem ntau yog tsim los ntawm kev ua kom sov lossis photochemical ntawm cov initiators xws li peroxides lossis azo compounds. Piv txwv li, hauv kev ua kom cov peroxides:
\[ ROOR \rightarrow 2RO\cdot \]
Cov free radical RO• ces tuaj yeem pib ua ib qho kev sib xyaw nrog ib lub monomer (piv txwv li, ethylene):
\[ RO\cdot + CH_2=CH_2 \rightarrow RO-CH_2-CH_2\cdot \]
2. Kev nthuav dav
Nyob rau theem kev nthuav dav, cov dawb radicals tsim nyob rau theem pib ua haujlwm nrog lwm cov monomers los tsim cov saw polymer ntev dua. Txhua zaus cov dawb radical cuam tshuam nrog cov monomer tshiab, cov saw polymer ntev dua:
\[ RO-CH_2-CH_2\cdot + CH_2=CH_2 \rightarrow RO-CH_2-CH_2-CH_2-CH_2\cdot \]
Cov txheej txheem no txuas ntxiv mus txog thaum ntau pua txog ntau txhiab tus monomers raug muab tso ua ke rau hauv cov saw polymer ntev.
3. Kev xaus
Kev xaus yog theem kawg ntawm kev sib xyaw ua ke uas cov saw hlau polymer loj hlob tsis muaj zog. Kev xaus tuaj yeem tshwm sim los ntawm ntau yam txheej txheem, xws li kev sib xyaw ua ke lossis kev tsis sib haum xeeb. Hauv kev sib xyaw ua ke, ob lub free radicals sib xyaw ua ke los tsim ib lub polymer molecule:
\[ RO-CH_2-CH_2\cdot + \cdot CH_2-CH_2-RO \rightarrow RO-CH_2-CH_2-CH_2-CH_2-RO \]
Hauv kev tsis sib npaug, cov dawb radicals nyob ze pauv cov hydrogen atoms los tsim ob lub unsaturated molecules:
\[ RO-CH_2-CH_2\cdot + \cdot CH_2-CH_2-RO \rightarrow RO-CH_2-CH_3 + CH_2=CH-RO \]
Cov ntawv thov ntawm kev ntxiv polymerization
Cov txheej txheem polymerization ntxiv yog siv los tsim ntau yam polymers nrog ntau yam kev siv thoob plaws hauv kev lag luam. Qee qhov kev siv tseem ceeb suav nrog plastics, roj hmab hluavtaws, thiab fibers.
1. Yas
Cov yas yog cov khoom tseem ceeb ntawm kev ntxiv polymerization. Polyethylene, polypropylene, polystyrene, thiab polyvinyl chloride (PVC) yog cov piv txwv ntawm cov yas tsim los ntawm kev ntxiv polymerization:
– Polyethylene (PE): Siv rau hauv cov khoom siv niaj hnub xws li cov hnab yas, cov khoom ua si rau menyuam yaus, thiab cov fwj dej haus.
– Polypropylene (PP): Siv dav hauv kev tsim cov rooj tog hauv tsev, cov khoom ntim khoom noj, thiab cov khoom siv hauv tsheb.
– Polystyrene (PS): Siv los ua cov khoom xws li cov thawv ntim khoom noj, cov khoom siv hauv chav kuaj, thiab cov khoom rwb thaiv tsev.
– Polyvinyl chloride (PVC): Siv rau hauv kev tsim cov kav dej, cov xov hlau, thiab cov ntaub ntawv siv hauv kev tsim kho.
2. Cov roj hmab ua los ntawm cov khoom siv hluavtaws
Cov roj hmab hluavtaws xws li polybutadiene thiab styrene-butadiene (SBR) kuj tseem tsim los ntawm kev ntxiv polymerization. Cov roj hmab hluavtaws no yog siv rau hauv kev tsim cov log tsheb, cov khau hauv qab, thiab ntau yam khoom siv roj hmab.
3. Cov fiber
Qee cov xov hluavtaws siv hauv kev lag luam textile kuj tsim los ntawm kev ntxiv polymerization. Piv txwv li suav nrog acrylic thiab polypropylene, uas yog siv rau hauv kev tsim khaub ncaws, ntaub pua plag, thiab lwm yam ntaub.
Cov txiaj ntsig ntawm kev ntxiv polymerization
Kev ntxiv polymerization coj ntau yam zoo uas ua rau nws muaj txiaj ntsig zoo hauv kev siv hauv kev lag luam.
1. Kev Ua Haujlwm Zoo
Kev ntxiv polymerization tso cai rau kev tsim cov polymers loj nrog kev tswj hwm zoo ntawm qhov ntev ntawm cov saw thiab kev faib tawm qhov hnyav ntawm cov molecular. Cov txheej txheem kuj tseem ceev thiab yooj yim rau kev teeb tsa, nrog rau cov xwm txheej uas tuaj yeem hloov kho kom tsim tau ntau yam polymers.
2. Tus nqi qis
Cov monomers siv rau hauv kev sib ntxiv polymerization feem ntau pheej yig thiab muaj ntau. Ntxiv mus, cov txheej txheem no tuaj yeem ua haujlwm nrog kev siv hluav taws xob tsawg kawg nkaus, pab txhawb rau kev siv nyiaj ntau ntawm cov txheej txheem tsim khoom.
3. Kev Siv Tau Ntau Yam Khoom
Kev ntxiv polymerization tuaj yeem tsim cov polymers nrog ntau yam khoom siv lub cev thiab lub cev. Los ntawm kev hloov hom monomer lossis kev tswj hwm cov xwm txheej ntawm kev ua haujlwm, cov chaw tsim khoom tuaj yeem tsim cov polymers uas tsim rau cov kev xav tau tshwj xeeb.
4. Kev ruaj khov thiab kev ruaj khov
Cov polymers tsim los ntawm kev ntxiv polymerization feem ntau yuav tiv taus ntau yam ib puag ncig, suav nrog qhov kub thiab txias, tshuaj lom neeg, thiab kev ntxhov siab ntawm lub cev. Qhov no ua rau lawv zoo tagnrho rau cov ntawv thov uas xav tau kev ruaj khov siab, xws li cov ntaub ntawv tsim kho thiab cov khoom siv hauv kev lag luam.
5. Kev rov ua dua tshiab
Muaj ntau cov polymers ntxiv, xws li polyethylene thiab polypropylene, uas siv tau dua tshiab, txhawb nqa kev siv zog ua kom ruaj khov thiab txo cov khib nyiab ib puag ncig. Qhov no tseem ceeb heev vim muaj kev paub ntau ntxiv txog kev cuam tshuam rau ib puag ncig ntawm cov yas pov tseg.
Cov Teeb Meem thiab Cov Kev Daws Teeb Meem
Txawm hais tias nws muaj ntau yam txiaj ntsig, kev ntxiv polymerization kuj ntsib ntau yam teeb meem uas yuav tsum tau daws kom txhim kho nws txoj kev ua haujlwm zoo thiab kev ruaj khov.
1. Kev Tswj Xyuas Cov Khoom Polymer
Kev tswj cov qauv thiab cov khoom ntawm cov polymers uas tshwm sim feem ntau yog qhov nyuaj. Cov kws tshawb fawb yuav tsum txuas ntxiv tsim cov hau kev los tswj kev faib tawm qhov hnyav molecular thiab kev teeb tsa stereochemical kom ua tiav qhov kev ua tau zoo tshaj plaws.
2. Kev Cuam Tshuam Rau Ib Puag Ncig
Kev tsim cov polymer feem ntau muaj kev cuam tshuam loj heev rau ib puag ncig. Kev siv cov peev txheej zoo thiab cov thev naus laus zis uas tsis ua rau ib puag ncig puas tsuaj yuav tsum tau txhim kho tas li kom txo cov pa roj carbon ntawm cov txheej txheem tsim cov polymer.
3. Cov Haujlwm Rov Siv Dua
Kev tsim cov thev naus laus zis rov ua dua tshiab uas ua tau zoo dua thiab muaj txiaj ntsig zoo dua yog qhov tseem ceeb rau kev tswj hwm qhov ntim ntawm cov khib nyiab polymer uas nce ntxiv. Kev txhim kho hauv kev cais thiab ua cov khib nyiab yas tuaj yeem ua lub luag haujlwm tseem ceeb hauv qhov kev siv zog no.
Xaus
Kev ntxiv polymerization ua lub luag haujlwm tseem ceeb hauv kev tsim ntau yam polymers uas txhawb nqa ntau yam ntawm lub neej niaj hnub. Txij li cov yas thiab roj hmab mus rau cov ntaub textile fibers, txoj kev no ua rau muaj kev tsim khoom siv tau zoo thiab pheej yig. Txawm hais tias nws ntsib qee qhov kev cov nyom, kev nce qib hauv thev naus laus zis thiab kev tshawb fawb tuaj yeem kov yeej cov teeb meem no thiab ua kom muaj txiaj ntsig zoo tshaj plaws ntawm kev ntxiv polymerization. Nrog kev txhim kho daim ntawv thov thiab kev ua kom zoo dua qub, kev ntxiv polymerization yuav tseem yog ib qho tseem ceeb hauv kev lag luam tshuaj lom neeg thiab kev tsim khoom, txhawb nqa kev hloov pauv mus rau lub zej zog ruaj khov dua.
