Cov txheej txheem tsim cov tshuaj acrylate reactive diluents feem ntau suav nrog kev esterification ncaj qha, transesterification, acid chloride method, phase-transfer catalysis, thiab ntxiv esterification. Txawm li cas los xij, feem ntau yog tsim los ntawm kev esterification ncaj qha.
(1) Kev Esterification Ncaj Qha
CH₂ = CHCOOH + ROH -catalyst → CH₂ = CHCOOR + H₂O
Cov tshuaj catalysts uas siv ntau rau kev esterification ncaj qha suav nrog concentrated sulfuric acid, p-toluenesulfonic acid, thiab methanesulfonic acid. Kev siv concentrated sulfuric acid ua ib qho esterification catalyst feem ntau ua rau muaj kev tsis haum xws li dehydration, oxidation, thiab self-esterification ntawm cov reactants. Qhov no tsim ntau yam khoom by-products, ua rau cov khoom purification thiab raw khoom rov qab nyuaj, cuam tshuam cov txheej txheem tom qab kho, thiab ua rau cov khoom zoo thaum corroding cov khoom siv. Yog li ntawd, PTSA feem ntau siv rau hauv kev tsim khoom lag luam tam sim no vim nws cov txiaj ntsig, suav nrog cov kev xav tau tsawg, qhov kub tsawg, cov nqi hloov pauv siab, thiab cov khoom zoo dua. Thaum ua tiav cov tshuaj, cov catalyst tuaj yeem sib cais tau yooj yim ntawm cov khoom, ua rau cov txheej txheem ua haujlwm yooj yim dua. Cov dej uas tsim tawm thaum lub sijhawm esterification reaction raug tshem tawm siv cov azeotropic entrainer (dehydrating agent). Cov entrainers feem ntau muaj xws li benzene, toluene, xylene, cyclohexane, thiab n-heptane, uas tsim cov azeotropes nrog cov dej reaction kom nqa nws mus. Alkanes kim heev thiab volatile heev; xylene muaj lub point boiling siab; benzene muaj lub point boiling qis thiab volatility siab, ua rau nws nyuaj rau rov qab tau, thiab nws muaj kev lom heev. Yog li ntawd, toluene feem ntau yog nyiam ua entrainer. Toluene muaj lub point boiling ntawm 110 ° C thiab lub point boiling dej-toluene azeotropic ntawm 84 ° C; nws yooj yim condenses thaum lub sijhawm nqus tsev distillation solvent stripping, ua kom ntseeg tau tias muaj kev rov qab tau zoo, kev lom tsawg dua li benzene, thiab tus nqi pheej yig. Txawm li cas los xij, nyob rau xyoo tas los no, kev txwv tsis pub muaj benzene-series solvents hauv coatings, inks, thiab adhesives tau ua rau ntau lub tuam txhab tsim khoom tshem tawm toluene thiab siv alkane-based entrainers. Cov tshuaj tiv thaiv polymerization yuav tsum tau siv thaum lub sijhawm esterification kom tiv thaiv kev polymerization ntawm acrylic acid monomer thiab cov khoom acrylate ua ntej lub sijhawm. Cov tshuaj tiv thaiv feem ntau siv suav nrog cov tshuaj phenolic (xws li hydroquinone [HQ] thiab tert-butylhydroquinone [TBHQ]), cov tshuaj amine (xws li phenothiazine thiab p-phenylenediamine), thiab cov tshuaj sib koom ua ke tooj liab (xws li tooj liab dimethyldiethyldithiocarbamate thiab tooj liab dibutyl dithiocarbamate), siv ib leeg lossis ua cov tshuaj sib xyaw. Rau cov alkyl acrylates siab dua, cov esterification yaj tuaj yeem siv tau. Txoj kev no tshem tawm qhov xav tau entrainer thiab txo qhov xav tau ntawm cov catalysts thiab inhibitors. Tom qab qhov tshuaj tiv thaiv reflux ntawm 110–120 ° C, dehydration yog ua, thiab cov acrylic acid tsis muaj zog thiab cov dej seem thaum kawg raug stripped los ntawm kev nqus tsev vacuum distillation, ua rau cov alkyl acrylates siab dua nrog kev ntshiab siab thiab cov txiaj ntsig siab.
(2) Kev Hloov Pauv
CH₂=CHCO₃ + ROH → CH₂=CHCOOR + CH₃OH
Thaum npaj cov alkyl acrylates siab dua lossis cov acrylates ua haujlwm los ntawm kev hloov pauv, methyl acrylate feem ntau yog xaiv ua cov khoom pib alkyl ester qis dua. Vim nws qhov kub qis (80 ° C), esterification yuav tsum tau ua ntawm qhov kub qis dua, uas ua rau lub sijhawm ua haujlwm ntev dua. Ntxiv mus, cov khoom methanol tsim cov azeotrope nrog methyl acrylate (kub 62-63 ° C), uas nqa cov reactant methyl acrylate thiab ua rau cov ester siab dua qis dua. Methyl acrylate thiab cov acrylates siab dua yooj yim rau copolymerization thiab homopolymerization, ua rau cov acrylates siab dua txo qis; yog li, ntau cov tshuaj inhibitors feem ntau yuav tsum tau ua. Vim yog kev txiav txim siab txog tus nqi thiab kev nyuaj tom qab kho, txoj kev no tsis siv rau kev lag luam rau kev tsim cov alkyl acrylates siab dua thiab cov acrylates ua haujlwm.
(3) Txoj Kev Siv Acid Chloride
CH₂ = CHCOOH + SOCl₂ → CH₂ = CHCOCl + HCl + CO₂
CH₂=CHCOCl + ROH → CH₂=CHCOOR + HCl
Txoj kev no ua ntej yuav ua rau acrylic acid nrog thionyl chloride los ua acryloyl chloride, uas tom qab ntawd yuav ua rau muaj kev sib xyaw ua ke nrog cawv. Nws tsis tas yuav muaj cov tshuaj catalysts lossis cov tshuaj entrainers. Vim tias qhov kev sib xyaw ua ke ntawm qhov kub qis, kev ntxiv cov tshuaj polymerization inhibitors kuj raug zam. Qhov kev sib xyaw ua ke yuav luag ntau, ua rau cov khoom huv si zoo heev. Txawm li cas los xij, nws yog ib qho txheej txheem ob kauj ruam nrog cov nqi tsim khoom siab. Qhov kev sib xyaw ua ke tsim cov pa roj HCl thiab SO₂ ntau heev, xav tau ntau theem kev txhuam nrog cov kua alkaline dilute thiab dej rau kev nqus.
(4) Kev Hloov Pauv Theem (PTC)
2CH₂=CH₃|C-COOH + Na₂CO₃ → 2CH₂=CH₃|C-COONa + CO₂ + H₂O
CH₂=CH₃|C-COONa + ClCH₂-CH₂O → CH₂=CH₃|C-COOCH₂-CH₂O + NaCl
Sodium methacrylate muaj nyob ua ib yam khoom khov, thaum epichlorohydrin yog ib yam kua. Yog tsis muaj catalyst, qhov kev sib xyaw ntawm lawv qeeb heev, ua rau yuav tsum siv cov catalyst hloov theem (PTC). Cov catalysts hloov theem uas tsim nyog suav nrog cov ntsev quaternary ammonium, cov ntsev quaternary phosphonium, thiab cov ethers crown. Cov ntsev quaternary ammonium yog cov uas muaj ntau tshaj plaws, xws li cetyltrimethylammonium chloride (CTAC), benzyltrimethylammonium chloride (BTMAC), thiab tetramethylammonium chloride (TMAC). Qhov muaj dej noo nyob rau hauv lub cev ua rau muaj kev sib xyaw sab; yog li ntawd, txhawm rau kom tau txiaj ntsig zoo tshaj plaws, ob qho tib si cov khoom siv raw thiab lub cev ua yuav tsum khaws cia kom tsis muaj dej thiab qhuav.
(5) Kev Ntxiv Esterification
CH₂=R₁|C-COOH + CH₂-CH₂O-R₂ → CH₂=R₁|C-COO-CH₂-OH|CH₂-R₂
Los ntawm kev qhia ethylene oxide lossis propylene oxide ncaj qha mus rau hauv (meth) acrylic acid nyob rau hauv lub xub ntiag ntawm ib tug catalyst, ib tug nplhaib-qhib ntxiv esterification tshwm sim, synthesizing hydroxy (meth) acrylates (xws li HEA, HEMA, HPA, lossis HPMA). 
Lub sijhawm tshaj tawm: Lub Rau Hli-10-2026
