Cov txheej txheem Transglycosidation siv D-glucose ua raw khoom.

Fischer glycosidation yog tib txoj kev ntawm cov tshuaj synthesis uas tau ua rau txoj kev loj hlob ntawm kev lag luam niaj hnub no thiab cov kev daws teeb meem zoo tshaj plaws rau cov khoom loj ntawm alkyl polyglucosides. Ntau cov nroj tsuag uas muaj peev xwm ntau dua 20,000 t / xyoo twb tau paub lawm thiab nthuav cov khoom lag luam ntawm surfactants kev lag luam nrog cov neeg ua haujlwm saum npoo av raws li cov khoom siv txuas ntxiv dua tshiab. D-Glucose thiab linear C8-C16 fatty alcohols tau ua pov thawj tias yog cov khoom noj uas nyiam. Cov educts no tuaj yeem hloov mus rau hauv qhov chaw ua haujlwm alkyl polyglycosides los ntawm kev ncaj qha Fischer glycosylation lossis los ntawm ob-kauj ruam transglycosides ntawm butyl polyglycoside nyob rau hauv muaj cov kua qaub catalyst, nrog dej raws li cov khoom lag luam. Dej yuav tsum tau distilled los ntawm cov tshuaj tiv thaiv sib tov kom hloov cov tshuaj tiv thaiv equilibrium mus rau cov khoom xav tau. Nyob rau hauv cov txheej txheem glycosylation, inhomogeneities nyob rau hauv cov tshuaj tiv thaiv sib tov yuav tsum raug zam vim hais tias lawv tuaj yeem ua rau ntau dhau ntawm cov hu ua polydextrose, uas yog qhov tsis xav tau. Yog li ntawd, ntau lub tswv yim kev tsom mus rau homogenous educts n-glucose thiab cawv, uas nyuaj rau miscible vim lawv cov polarities sib txawv. Thaum lub sij hawm cov tshuaj tiv thaiv, glycosidic bonds yog tsim ob qho tib si ntawm fatty cawv thiab n-glucose thiab ntawm n-glucose units lawv tus kheej. Alkyl polyglucosides yog li tsim los ntawm cov khoom sib xyaw nrog cov lej sib txawv ntawm cov piam thaj hauv cov saw ntev alkyl residue. Txhua qhov ntawm cov feem, nyob rau hauv lem, yog tsim los ntawm ob peb isomeric constituents, txij li thaum lub n-qabzib units xav tias txawv anomeric forms thiab nplhaib cov ntaub ntawv nyob rau hauv tshuaj sib npaug zos thaum lub sij hawm Fischer glycosidation thiab cov glycosidic linkages ntawm D-glucose units tshwm sim nyob rau hauv ob peb ua ke txoj hauj lwm. . Qhov sib piv anomer ntawm D-glucose units yog kwv yees li α / β＝ 2: 1 thiab zoo li nyuaj rau cuam tshuam raws li kev piav qhia ntawm Fischer synthesis. Nyob rau hauv cov txheej txheem thermodynamically tswj, cov n-glucose units muaj nyob rau hauv cov khoom sib tov muaj nyob rau hauv daim ntawv ntawm pyranosides. Qhov nruab nrab ntawm cov piam thaj ib txwm nyob rau ib qho alkyl residue, lub npe hu ua degree ntawm polymerization, yog qhov ua haujlwm ntawm molar ratio ntawm educts thaum lub sijhawm tsim khoom. Vim lawv cov khoom zoo tshaj plaws surfactant, alkyl polyglycosides nrog rau qib ntawm polymerization ntawm 1 thiab 3 yog qhov tshwj xeeb tshaj yog nyiam, vim li cas txog 3-10 moles ntawm fatty alcohols yuav tsum tau siv ib mole ntawm cov piam thaj ib txwm nyob rau hauv txoj kev no.

Qhov degree ntawm polymerization txo qis ntawm qhov nce ntxiv ntawm cov dej cawv muaj roj. Cov dej cawv ntau dhau yog sib cais thiab rov zoo los ntawm kev siv ntau lub tshuab nqus tsev distillation nrog cov evaporators ntog, uas ua rau nws muaj peev xwm ua kom lub thermal stress tsawg kawg nkaus. Lub evaporation kub yuav tsum tsuas yog siab txaus thiab lub sij hawm sib cuag nyob rau hauv lub kub cheeb tsam tsuas yog ntev txaus los xyuas kom meej txaus distillation ntawm ntau tshaj ntawm fatty cawv thiab ntws ntawm alkyl polyglucoside yaj, tsis muaj qhov tshwm sim ntawm ib qho kev cuam tshuam loj heev decomposition. Cov kauj ruam ntawm evaporation tuaj yeem ua haujlwm tau zoo los cais thawj qhov qis qis, tom qab ntawd qhov tseem ceeb ntawm cov dej cawv muaj roj, thiab thaum kawg cov roj cawv tseem tshuav kom txog rau thaum alkyl polyglucoside melts tau txais cov dej-soluble residues.

Txawm tias thaum synthesis thiab evaporation ntawm fatty cawv yog ua nyob rau hauv lub feem ntau mos mos tej yam kev mob, undesired xim av discoloration tshwm sim, hu rau bleaching txheej txheem los kho cov khoom. Ib txoj kev tshuaj dawb uas tau ua pov thawj tias tsim nyog yog qhov sib ntxiv ntawm oxidants xws li hydrogen peroxide rau aqueous npaj ntawm alkyl polyglucosides hauv alkaline nruab nrab nyob rau hauv muaj magnesium ions.

Cov kev tshawb nrhiav thiab kev sib txawv ua haujlwm thaum lub sijhawm sib txuas, ua haujlwm, thiab kho kom zoo nkauj qhia tau tias txawm tias niaj hnub no tseem tsis muaj feem cuam tshuam "turnkey" kev daws teeb meem kom tau txais cov khoom lag luam tshwj xeeb. Ntawm qhov tsis sib xws, tag nrho cov txheej txheem yuav tsum tau ua kom tiav, sib kho, thiab ua kom zoo. Tshooj lus no tau muab cov lus qhia thiab piav qhia txog qee txoj hauv kev siv tau los tsim cov kev daws teeb meem, nrog rau hais txog cov txheej txheem tshuaj thiab lub cev rau kev coj ua, kev sib cais, thiab kev ua kom zoo.

Tag nrho peb cov txheej txheem tseem ceeb - homogeneous transglycosidation, txheej txheem slurry, thiab cov txheej txheem kev noj qabzib - tuaj yeem siv tau raws li kev lag luam. Thaum lub sij hawm transglycosidation, qhov concentration ntawm intermediate butyl polyglucoside, uas ua raws li ib tug solubilizer rau educts D-glucose thiab butanol, yuav tsum tau khaws cia ntau tshaj li 15% nyob rau hauv cov tshuaj tiv thaiv sib tov kom tsis txhob inhomogeneities. Rau tib lub hom phiaj, cov dej concentration hauv cov tshuaj tiv thaiv sib xyaw ua haujlwm rau ncaj qha Fischer synthesis ntawm alkyl polyglucosides yuav tsum khaws cia tsawg dua li 1%. Nyob rau hauv cov dej ntau dua muaj kev pheej hmoo ntawm kev hloov cov crystalline D-glucose uas raug tshem tawm mus rau hauv ib qho tacky loj, uas yuav ua rau kev ua tsis zoo thiab ntau dhau ntawm polymerization. Kev sib xyaw kom zoo thiab homogenization txhawb kev sib faib zoo thiab rov ua haujlwm ntawm crystalline D-glucose hauv cov tshuaj tiv thaiv sib tov.

Ob qho tib si technical thiab economic yam yuav tsum tau txiav txim siab thaum xaiv cov txheej txheem ntawm synthesis thiab nws cov sophisticated variants ntau. Homogeneous transglycosidation txheej txheem raws li D-glucose syrups tshwm sim tshwj xeeb tshaj yog muaj txiaj ntsig zoo rau kev tsim khoom tas mus li ntawm qhov loj. Lawv tso cai rau kev khaws cia mus tas li ntawm crystallization ntawm cov khoom siv raw D-glucose nyob rau hauv cov khoom muaj nqis ntxiv, uas ntau dua li them nyiaj rau kev nqis peev ntau dua ib zaug hauv cov kauj ruam transglycosidation thiab rov qab los ntawm butanol. Kev siv n-butanol nthuav tawm tsis muaj lwm yam tsis zoo, vim nws tuaj yeem rov ua dua yuav luag tag kom cov khoom seem seem hauv cov khoom kawg rov qab tsuas yog ob peb feem ntawm ib lab, uas tuaj yeem suav tias yog qhov tsis tseem ceeb. Direct Fischer glycosidation raws li cov txheej txheem slurry los yog cov txheej txheem kev noj qab haus huv dispenses nrog cov kauj ruam transglycosidation thiab rov qab los ntawm butanol. Nws tseem tuaj yeem ua tau tsis tu ncua thiab hu rau kev siv nyiaj qis me ntsis.

Lub neej yav tom ntej muaj thiab cov nqi ntawm cov pob txha thiab cov khoom siv txuas ntxiv dua tshiab, nrog rau kev nce qib ntxiv hauv kev tsim khoom thiab kev siv cov alkyl polyglucosides, tej zaum yuav xav tias yuav muaj kev txiav txim siab rau txoj kev loj hlob ntawm kev lag luam tom qab ntim thiab kev tsim khoom. Cov kev daws teeb meem uas twb muaj lawm rau kev tsim khoom thiab siv cov alkyl polyglucosides tuaj yeem ua rau muaj kev sib tw tseem ceeb hauv kev ua lag luam surfactants rau cov tuam txhab uas tau tsim lossis twb ua haujlwm li cov txheej txheem. Qhov no yog qhov tseeb tshwj xeeb tshaj yog thaum muaj cov nqi roj crude siab thiab cov khoom noj khoom haus qis. Txij li cov nqi tsim khoom ruaj khov yog nyob rau theem kev cai rau ntau cov khoom lag luam surfactants, txawm tias kev txo qis me ntsis ntawm cov nqi ntawm cov khoom siv raw tuaj yeem yaum kom hloov cov khoom lag luam surfactants thiab yuav qhia meej txog kev txhim kho cov nroj tsuag tshiab rau alkyl polyglucosides.