1. Kev piav qhia txog methyl hydroxyethyl cellulose (MHEC)
Methyl hydroxyethyl cellulose (MHEC) yog ib qho cellulose ether uas tsis yog ionic tau los ntawm kev hloov kho methylation raws li hydroxyethyl cellulose. Vim nws cov qauv molecular tshwj xeeb, MHEC muaj kev yaj zoo, tuab, nplaum, tsim zaj duab xis thiab ua haujlwm ntawm qhov chaw, thiab tau siv dav hauv cov txheej txheem, cov ntaub ntawv tsim kho, cov tshuaj txhua hnub thiab lwm yam teb.
2. Kev piav qhia txog cov tshuab pleev xim
Cov tshuaj pleev xim yog cov tshuaj siv los tshem cov xim pleev xws li hlau, ntoo, thiab yas. Cov tshuaj pleev xim ib txwm muaj feem ntau siv cov tshuaj yaj hnyav, xws li dichloromethane thiab toluene. Txawm hais tias cov tshuaj no ua haujlwm tau zoo, lawv muaj teeb meem xws li kev hloov pauv siab, kev lom thiab kev phom sij rau ib puag ncig. Nrog rau kev cai lij choj ib puag ncig uas nruj zuj zus thiab kev txhim kho cov kev cai ntawm ib puag ncig ua haujlwm, cov tshuaj pleev xim uas siv dej thiab tsis muaj tshuaj lom tau maj mam dhau los ua lub ntsiab lus tseem ceeb ntawm kev ua lag luam.
3. Txoj kev ua haujlwm ntawm MHEC hauv cov khoom siv pleev xim
Hauv cov tshuaj pleev xim, MHEC ua lub luag haujlwm tseem ceeb ua tus thickener thiab rheology modifier:
Cov nyhuv tuab:
MHEC muaj cov nyhuv ua kom tuab zoo hauv cov txheej txheem dej. Los ntawm kev kho qhov viscosity ntawm cov tshuaj pleev xim, MHEC tuaj yeem ua rau cov tshuaj pleev xim lo rau ntawm cov chaw ntsug lossis cov chaw nkhaus yam tsis muaj kev sagging. Cov yam ntxwv no tseem ceeb heev thaum siv cov tshuaj pleev xim vim nws tso cai rau cov tshuaj pleev xim kom nyob twj ywm ntawm qhov chaw xav tau ntev dua, yog li txhim kho cov nyhuv pleev xim.
Ua kom lub kaw lus ncua ruaj khov:
Cov tshuaj pleev xim feem ntau muaj ntau yam khoom xyaw nquag, uas yuav ua rau sib cais lossis poob thaum khaws cia. Los ntawm kev txhim kho qhov viscosity ntawm cov tshuaj, MHEC tuaj yeem tiv thaiv kev poob ntawm cov khoom khov, tswj kev faib tawm ntawm cov khoom xyaw, thiab xyuas kom meej tias cov tshuaj pleev xim ua haujlwm ruaj khov.
Kho cov khoom rheological:
Kev siv cov tshuaj pleev xim yuav tsum tau muaj cov khoom zoo rheological, uas yog, nws tuaj yeem ntws tau zoo thaum muaj zog sab nraud, tab sis tuaj yeem tuab sai thaum tsis txav. Cov qauv molecular saw ntawm MHEC muab cov khoom zoo shear thinning, uas yog, ntawm qhov nrawm siab, qhov viscosity ntawm cov tshuaj yuav txo qis, ua rau cov tshuaj pleev xim yooj yim dua rau kev siv; thaum ntawm qhov nrawm qis lossis nyob rau hauv lub xeev tsis txav, qhov viscosity ntawm cov tshuaj yog siab, uas pab cov khoom tsim ib txheej txheej sib xws ntawm qhov chaw ntawm lub hom phiaj.
Txhawb kev tsim cov yeeb yaj kiab:
Thaum lub sijhawm tshem xim, MHEC tuaj yeem pab tus neeg tshem xim tsim ib daim zaj duab xis sib xws rau ntawm qhov chaw uas xav tau. Daim zaj duab xis no tsis yog tsuas yog ua rau lub sijhawm ua haujlwm ntawm cov khoom xyaw nquag ntev dua xwb, tab sis kuj tseem txhim kho lub peev xwm npog ntawm tus neeg tshem xim mus rau qee qhov, kom nws tuaj yeem nkag mus rau hauv txhua qhov ntawm cov txheej.
4. Yuav siv MHEC li cas rau cov tshuab pleev xim
Kev npaj cov kua dej:
Feem ntau MHEC muaj nyob rau hauv daim ntawv hmoov thiab yuav tsum tau npaj rau hauv cov kua dej ua ntej siv. Kev coj ua feem ntau yog maj mam ntxiv MHEC rau hauv cov dej uas tau do kom tsis txhob sib sau ua ke. Nws yuav tsum nco ntsoov tias qhov solubility ntawm MHEC yuav raug cuam tshuam los ntawm qhov kub ntawm dej thiab tus nqi pH. Qhov kub ntawm dej siab dua (50-60 ℃) tuaj yeem ua kom cov txheej txheem yaj ntawm MHEC sai dua, tab sis qhov kub siab dhau yuav cuam tshuam rau nws qhov kev ua haujlwm viscosity.
Sib xyaw rau hauv cov xim pleev xim:
Thaum npaj cov tshuaj pleev xim, feem ntau cov kua dej MHEC yuav tsum maj mam ntxiv rau hauv cov kua pleev xim thaum do. Yuav kom paub tseeb tias muaj kev sib xyaw zoo, qhov ceev ntawm kev ntxiv MHEC yuav tsum tsis txhob nrawm dhau, thiab yuav tsum txuas ntxiv do kom txog thaum tau txais cov kua sib xyaw zoo. Cov txheej txheem no yuav tsum tswj qhov ceev ntawm kev do kom tiv thaiv kev tsim cov npuas.
Kev kho cov mis:
Feem ntau, cov MHEC uas muaj nyob hauv cov tshuaj pleev xim yuav raug kho raws li cov mis tshwj xeeb thiab lub hom phiaj ntawm cov tshuaj pleev xim. Feem ntau, cov tshuaj ntxiv yog li ntawm 0.1% -1%. Yog tias cov tshuaj tuab dhau, nws yuav ua rau cov xim tsis sib npaug lossis viscosity ntau dhau, thiab yog tias cov tshuaj tsis txaus, nws yuav tsis ua rau cov viscosity thiab rheological zoo tshaj plaws, yog li ntawd, nws yog ib qho tsim nyog los sim ua kom zoo dua qub.
5. Cov txiaj ntsig ntawm MHEC hauv cov tshuab pleev xim
Kev nyab xeeb thiab kev tiv thaiv ib puag ncig:
Piv nrog cov thickeners ib txwm muaj, MHEC yog cov cellulose ether uas tsis yog ionic, tsis muaj cov tshuaj lom thiab cov tshuaj lom, muaj kev nyab xeeb dua rau tib neeg lub cev thiab ib puag ncig, thiab ua raws li kev coj ua ntawm cov tshuaj ntsuab niaj hnub.
Kev ruaj khov zoo heev: MHEC muaj kev ruaj khov tshuaj zoo hauv ntau qhov pH (pH 2-12), tuaj yeem tswj tau qhov ua kom tuab ruaj khov hauv ntau lub tshuab pleev xim, thiab tsis yooj yim cuam tshuam los ntawm lwm yam khoom hauv lub kaw lus.
Kev Sib Txuas Zoo: Vim yog qhov xwm txheej tsis yog ionic ntawm MHEC, nws sib raug zoo nrog feem ntau cov khoom xyaw nquag, yuav tsis cuam tshuam lossis ua rau lub kaw lus tsis ruaj khov, thiab tsim nyog rau ntau hom kev tsim cov xim pleev xim.
Cov nyhuv ua kom tuab zoo: MHEC tuaj yeem muab cov nyhuv ua kom tuab zoo, yog li txo cov khoom ua kom tuab hauv cov xim pleev xim, ua kom cov mis yooj yim dua thiab txo cov nqi.
Methyl hydroxyethyl cellulose (MHEC) tau siv dav hauv cov tshuaj pleev xim niaj hnub no vim nws ua kom tuab, ruaj khov thiab sib xws. Los ntawm kev tsim thiab siv cov mis tsim nyog, MHEC tuaj yeem txhim kho kev ua haujlwm ntawm cov tshuaj pleev xim, ua rau lawv ua haujlwm tau zoo dua thiab tiv thaiv ib puag ncig hauv kev siv. Yav tom ntej, nrog rau kev txhim kho tas mus li ntawm cov thev naus laus zis pleev xim thiab kev txhim kho ntxiv ntawm cov kev cai tiv thaiv ib puag ncig, kev siv MHEC hauv cov tshuaj pleev xim yuav dav dua.
Lub sijhawm tshaj tawm: Lub Rau Hli-14-2024