Hydroxyethyl cellulose (HEC) yog tsis-ionic, dej-soluble polymer muab tau los ntawm cellulose los ntawm kev hloov kho tshuaj lom neeg. Nws pom ntau yam kev lag luam vim nws cov khoom tshwj xeeb, xws li thickening, ruaj khov, thiab zaj ua yeeb yam zoo. Hauv cov ntawv thov uas yog qhov tseem ceeb heev, nkag siab txog kev coj tus cwj pwm li cas hauv PH cov kev cai yog qhov tseem ceeb.
Lub PE ruaj khov ntawm HEC uas yog hais txog nws lub peev xwm los tswj hwm nws cov qauv txheej txheem kev ncaj ncees, rheological cov khoom, thiab kev ua tau zoo nyob thoob plaws ib puag ncig PC. Qhov kev ruaj khov no yog qhov tseem ceeb hauv kev thov xws li cov khoom lag luam ntawm tus kheej, cov khoom siv, cov khoom siv, qhov chaw uas siv nyob ib puag ncig tuaj yeem sib txawv.
Tus qauv:
HEC feem ntau yog synthesized los ntawm reacting cellulose nrog ethylene oxide nyob rau hauv alkaline tej yam kev mob. Cov txheej txheem no ua rau cov pawg hauv hydroxyl ntawm cov pawg cellulose nrog hydroxyethyl (-och2ch2oh) pawg. Cov degree ntawm kev hloov pauv (DS) qhia txog qhov nruab nrab tus naj npawb ntawm cov pab pawg hydroxyethyl ib pawg ntawm cov xov xwm cellule.
Khoom:
Solubility: HEC yog soluble hauv dej thiab cov ntaub ntawv ntshiab, viscous daws teeb meem.
Viscosity: Nws ua yeeb yam pseudopastic lossis shear-thinning tus cwj pwm, lub ntsiab lus nws viscosity txo qis nyob rau hauv shear kev ntxhov siab. Cov cuab yeej no ua rau nws muaj txiaj ntsig hauv cov ntawv thov uas ntws yog qhov tseem ceeb, xws li cov xim thiab pleev xim.
Thickening: HEC CARNARTS viscosity rau cov kev daws teeb meem, ua rau nws muaj txiaj ntsig zoo li tus neeg sawv cev tuab tuab ntawm cov qauv.
Zaj duab xis-tsim: nws tuaj yeem tsim cov yeeb yaj kiab thiab pob tshab thaum qhuav hauv cov ntawv thov zoo li cov nplaum thiab cov txheej txheem.
PE ruaj khov ntawm HEC
Lub PE ruaj khov ntawm Hec yog cuam tshuam los ntawm ntau yam, suav nrog cov qauv tshuaj lom neeg ntawm cov qauv siv tshuaj, thiab kev sib ntxiv nrog cov qauv.
PE ruaj khov ntawm hac nyob rau hauv hom sib txawv:
1. Acidic Ph:
Ntawm acidic pH, HEC feem ntau ruaj khov tab sis tuaj yeem dhau hydrolysis nyob rau ncua sij hawm nyob rau hauv harsh acidic tej yam kev mob. Txawm li cas los xij, hauv cov ntawv thov siv feem ntau, xws li cov khoom lag luam ntawm tus kheej thiab cov txheej txheem accitings, qhov twg acidic p tau ntsib, HEC tseem nyob rau hauv cov phales pre (PH 3 txog 6). Tshaj li PH 3, qhov kev pheej hmoo ntawm kev pheej hmoo ntawm cov hydrolysis nce, ua rau kev txo qis hauv viscosity thiab kev ua tau zoo. Nws yog qhov tseem ceeb los saib xyuas lub ph ntawm cov qauv uas muaj hec thiab kho lawv raws li tsim nyog los tswj kev ruaj khov.
2. Nruab nrab PH:
Hec pom meej meej ruaj khov nyob rau hauv nruab nrab p tus mob (pH 6 txog 8). Cov xov no ntev yog muaj nyob rau ntau cov ntawv thov, suav nrog cov tshuaj pleev ib ce, tshuaj, thiab khoom siv hauv tsev. Hec-muaj cov kev tsim qauv khaws lawv viscosity, thickening cov yam ntxwv, thiab tag nrho kev ua tau zoo hauv cov kab no. Txawm li cas los xij, yam xws li kub thiab ionic lub zog tuaj yeem cuam tshuam kev ruaj khov thiab yuav tsum tau txiav txim siab thaum lub sijhawm tsim kev txhim kho.
3. Alkaline PH:
HEC tsis tshua ruaj ruaj nyob rau hauv Alkaline tej yam kev mob piv rau cov kua qaub lossis nruab nrab PH. Hauv PH theem (saum pH 8), HEC tuaj yeem raug teeb meem dhau los, ua rau muaj kev txo qis hauv viscosity thiab ploj ntawm kev ua tau zoo. Alkaline hydrolysis ntawm ether kev sib txuas ntawm cov kab mob cellules thiab cov pab pawg hydrothethyl tuaj yeem tshwm sim, ua rau qhov hnyav saw thiab txo cov molecular hnyav. Yog li ntawd, hauv cov qauv alkaline xws li cov ntaub ntawv siv ua haujlwm xws li cov ntaub ntawv tsim kho, lwm cov polymers lossis stabilizers yuav nyiam HEC.
Yam cuam tshuam rau kev ruaj khov
Ntau ntau yam tuaj yeem cuam tshuam rau lub pha kev ruaj khov ntawm HEC:
DSURSURDURDURDURDURDURDURDURDURDURDURE DS qhov tseem ceeb yog qhov ruaj khov ntawm cov pab pawg hydroxyethyl thiab tsis kam mus rau hydroxyethyl pawg thiab kuj mus rau hydroxyethyl pawg thiab kuj mus rau hydroxyethyl pawg thiab kuj mus rau hydroxyethyl pawg thiab kuj mus rau hydroxyethyl pawg thiab kuj mus rau hydroxyethyl pawg thiab kuj mus rau hydroxyethyl pawg thiab kuj mus rau hydroxyethyl pawg thiab kuj mus rau hydroxyethyl pawg thiab kuj mus rau hydroxyethyl pawg thiab kuj mus rau hydroxyethyl pawg thiab kuj mus rau hydroxyethyl pawg thiab kuj mus rau cov dej kas fes.
Qhov kub thiab txias: nce qhov kub tuaj yeem nrawm cov tshuaj tiv thaiv cov tshuaj, suav nrog kev kub ntxhov. Yog li no, tswj cov chaw cia uas tsim nyog thiab ua qhov kub yog qhov tseem ceeb rau kev khaws cia lub pH ruaj khov ntawm hec-uas muaj cov qauv.
Lub zog: muaj cov ntsev siab lossis lwm yam ions nyob rau hauv cov qauv muaj peev xwm cuam tshuam rau nws solubility thiab kev sib cuam tshuam nrog dej lwg me me. Ionic lub zog yuav tsum tau ua kom zoo rau tsawg kawg destabilizing cuam tshuam.
Cov tshuaj ntxiv: kev sib txuam ntawm cov quav nrog cov surfactives xws li surfactants, lossis buffering agents tuaj yeem cuam tshuam lub pha kev ruaj khov ntawm hec formulations. Kev ntsuas kev sib raug yuav tsum tau ua kom haum xeeb yuav tsum tau ua kom ntseeg tau tias muaj peev xwm ntxiv thiab kev ruaj khov.
Cov ntawv thov thiab cov kev txiav txim siab tsim qauv
Nkag siab txog qhov kev ruaj khov ntawm HEC yog qhov tseem ceeb rau cov ntawv hauv ntau yam kev lag luam.
Nov yog qee qhov kev thov tshwj xeeb:
Cov khoom siv saib xyuas tus kheej: nyob rau hauv cov khoom siv zawv plaub hau, tswj cov ntawv kom muaj qhov tsis muaj qhov (feem ntau nyob ib ncig ntawm Hec ua kev ua kom tuab thiab raug ncua.
Kws Tshuaj: HEC tau siv rau hauv kev ncua sijhawm, cov kev daws teeb meem ophthalmic, thiab cov ntsiab lus. Cov qauv yuav tsum tau tsim thiab khaws cia nyob rau hauv cov xwm txheej uas khaws cia Hec ruaj khov kom ntseeg tau cov khoom ua tau zoo thiab txee lub neej.
Cov xim pleev xim rau cov xim tha xim: HEC tau ua haujlwm raws li cov duab rheology thiab cov xim tuab hauv cov xim tsev thiab pleev xim. Cov kws sau ntawv yuav tsum tshuav nyiaj li cas nrog lwm cov txheej txheem ua tau zoo xws li viscosity, kev tsim qauv kev ua yeeb yam, thiab zaj duab xis.
Cov khoom siv tsim kho: nyob rau hauv kev txawj ntse, HEC ua raws li dej rov qab tus neeg saib xyuas thiab txhim kho cov haujlwm. Txawm li cas los xij, cov xwm txheej alkaline hauv cov cement tuaj yeem sib tw HECTISTY, xav tau kev xaiv kom zoo thiab tsim kev kho kom haum.
Hydroxyethyl cellulose (HEC) muaj cov txiaj ntsig muaj txiaj ntsig zoo thiab cov khoom muaj nuj nqis hauv ntau yam kev siv. Nkag siab nws lub ruaj khov yog qhov tseem ceeb rau cov protriculators los tsim cov qauv ruaj khov thiab ua tau zoo. Thaum Hec pom tau zoo ruaj khov nyob rau hauv nruab nrab p mob, kev txiav txim yuav tsum yog ua rau cov acidic thiab alkaline ib puag ncig kom tiv thaiv kev ua kom pom kev zoo. Los ntawm kev xaiv HEC muaj txiaj ntsig tsim nyog, ua kom tsim nyog tsim qauv, thiab cov qauv tsim nyog tau ua kom cov txiaj ntsig ntawm Hec hla kev dav dav ntawm cov qauv pH thoob plaws.
Lub Sijhawm Post: Mar-29-2024