Hydroxypropyl methylcellulose (HPMC) yog ib qho polymer compound dav siv nyob rau hauv kev tsim kho thiab coatings industries. Vim nws cov khoom siv tshuaj lom neeg thiab lub cev tshwj xeeb, nws tuaj yeem txhim kho kev ua haujlwm ntawm cov txheej txheem, tshwj xeeb tshaj yog txhawm rau txhim kho adhesion. Hauv cov txheej txheem txheej txheej, adhesion yog qhov tseem ceeb los xyuas kom muaj kev sib raug zoo ntawm cov txheej txheem thiab cov substrate thiab txhim kho cov kav ntev thiab kev pab lub neej ntawm txheej. Raws li cov khoom siv ntxiv, HPMC tuaj yeem txhim kho nws cov adhesion hauv ntau hom txheej txheej.
1. Cov qauv thiab cov yam ntxwv ntawm HPMC
HPMC yog cellulose etherified derivative, uas yog tsim los ntawm etherification cov tshuaj tiv thaiv ntawm pawg hydroxyl ntawm cellulose molecule nrog methyl thiab hydroxypropyl compounds. Cov qauv molecular ntawm HPMC muaj cov pob txha cellulose thiab cov khoom siv hloov pauv, thiab nws cov khoom tuaj yeem hloov kho los ntawm kev qhia txog cov khoom sib txawv. Cov qauv molecular no muab HPMC zoo heev solubility, thickening, adhesiveness thiab film-forming zog.
Cov khoom adhesion ntawm HPMC yog ze ze rau nws lub peev xwm hydration. Thaum HPMC yaj nyob rau hauv dej, cov molecules nqus dej thiab o los ua ib tug high-viscosity gel qauv. Cov gel no muaj zog adsorption thiab adhesion, tuaj yeem ua rau lub qhov hws ntawm lub substrate, ua kom lub ntsej muag smoothness thiab uniformity ntawm substrate, thiab yog li txhim kho tag nrho cov adhesion kev ua tau zoo ntawm txheej.
2. Mechanism ntawm kev txiav txim ntawm HPMC hauv cov txheej txheem
Hauv cov txheej txheem txheej txheej, lub luag haujlwm tseem ceeb ntawm HPMC yog ua cov thickener, tshem tawm tus neeg sawv cev thiab stabilizer, thiab cov haujlwm no cuam tshuam ncaj qha rau cov adhesion ntawm txheej.
2.1 Thickening nyhuv
HPMC yog cov thickener zoo uas tuaj yeem ua kom cov viscosity ntawm txheej txheej txheej thiab muab cov txheej txheem kev tsim kho zoo. Lub viscosity ntawm cov txheej yog ib qho tseem ceeb cuam tshuam rau nws cov fluidity, kis tau thiab npog lub zog ntawm lub substrate. Los ntawm kev kho tus nqi ntawm HPMC ntxiv, txheej txheej ntawm cov viscosities sib txawv tuaj yeem tau txais los ua kom tau raws li kev tsim kho sib txawv. Qhov tsim nyog txheej txheej viscosity pab cov txheej txheej kom sib npaug ntawm qhov chaw ntawm lub substrate thiab tsim cov txheej txheem du, yog li txhim kho cov adhesion ntawm txheej.
2.2 Suspension thiab stabilization nyhuv
Nyob rau hauv cov dej-raws li txheej txheej, cov khoom siv xws li pigments thiab fillers yuav tsum tau sib npaug ntawm cov txheej txheem txheej txheej kom tiv thaiv sedimentation thiab stratification. HPMC kev daws teeb meem muaj kev ncua zoo thiab kev ruaj ntseg, thiab tuaj yeem tsim cov qauv sib txuas hauv cov txheej txheem txheej txheej, ua kom zoo qhwv thiab txhawb nqa cov khoom ua kom lawv sib npaug. Kev ncua zoo thiab ruaj khov tuaj yeem ua kom ntseeg tau tias cov txheej txheem tswj kev sib xws thaum lub sijhawm khaws cia thiab kev tsim kho, txo qhov tso tawm ntawm cov xim lossis cov khoom ntim, thiab txhim kho cov tsos zoo thiab adhesion ntawm txheej.
2.3 Film-forming effect
HPMC muaj peev xwm tsim tau zaj duab xis muaj zog thiab tuaj yeem tsim cov yeeb yaj kiab hloov pauv thaum lub sijhawm ziab ntawm txheej txheej. Cov yeeb yaj kiab no tuaj yeem tsis tsuas yog txhim kho cov neeg kho tshuab lub zog ntawm txheej nws tus kheej, tab sis kuj tseem ua lub luag haujlwm txuas ntawm substrate thiab txheej. Tom qab HPMC zaj duab xis tsim, nws tuaj yeem sau cov kab nrib pleb me me thiab qhov tsis sib xws ntawm qhov chaw ntawm lub substrate, yog li ua rau thaj chaw sib cuag ntawm cov txheej thiab cov substrate thiab txhim kho lub cev adhesion ntawm txheej. Tsis tas li ntawd, kev ua yeeb yaj kiab-kev ua haujlwm ntawm HPMC tuaj yeem txo cov kab nrib pleb thiab tev tawm ntawm cov txheej txheej, ntxiv dag zog rau cov txheej txheem.
3. Kev siv HPMC hauv ntau hom txheej txheej
Nyob ntawm cov txheej txheem sib txawv, qhov kev ua kom zoo ntawm HPMC kuj yuav txawv. Cov hauv qab no yog cov piv txwv ntawm HPMC daim ntawv thov nyob rau hauv ntau hom txheej txheej:
3.1 Cov txheej txheem dej
Hauv cov txheej txheem dej, HPMC tuaj yeem txhim kho qhov ua tau zoo thiab kev tsim kho ntawm cov txheej txheem los ntawm ntau yam cuam tshuam xws li thickening, ncua kev kawm ntawv thiab kev tsim zaj duab xis. Txij li thaum HPMC muaj cov dej solubility zoo, nws tuaj yeem tawg sai sai hauv cov dej-raws li txheej txheej los tsim cov kev daws teeb meem ruaj khov. Tsis tas li ntawd, HPMC tseem tuaj yeem txhim kho cov dej tuav ntawm cov txheej txheem dej thiab tiv thaiv kev tawg thiab txo qhov adhesion los ntawm kev poob dej ntau dhau thaum lub sijhawm ziab.
3.2 Qhuav mortar
HPMC kuj tau siv dav hauv mortar qhuav. Qhuav mortar yog cov khoom siv feem ntau siv hauv tsev kho kom zoo nkauj, uas yog tov nrog dej los tsim cov txheej. Nyob rau hauv cov txheej txheem no, cov thickening thiab zaj duab xis-tsim los ntawm HPMC tuaj yeem txhim kho lub zog sib txuas ntawm cov mortar, ua rau nws ruaj khov rau cov substrates xws li phab ntsa lossis hauv pem teb. Tsis tas li ntawd, cov cuab yeej tuav dej ntawm HPMC tuaj yeem tiv thaiv cov dej hauv cov mortar los ntawm evaporating sai heev, yog li xyuas kom cov adhesion ntawm lub mortar thaum tsim thiab ziab.
3.3 Adhesive txheej
Hauv cov nplaum nplaum, HPMC yog siv los ua cov tackifier los txhim kho cov adhesion ntawm txheej. Cov qauv colloidal tsim los ntawm nws cov tshuaj tuaj yeem tsis tsuas yog txhim kho lub cev adhesion ntawm txheej thiab substrate, tab sis kuj txhim khu lub zog cohesive ntawm cov nplaum, kom ntseeg tau tias cov txheej txheem tswj tau zoo adhesion nyob rau hauv ib puag ncig sib txawv.
4. Qhov zoo ntawm HPMC hauv kev txhim kho adhesion
Raws li kev ua haujlwm ntxiv hauv cov txheej txheej, HPMC muaj cov txiaj ntsig hauv qab no hauv kev txhim kho adhesion:
Cov dej solubility zoo thiab kev sib raug zoo: HPMC tuaj yeem yaj hauv ntau cov kuab tshuaj thiab ua tau zoo nrog lwm cov tshuaj ntxiv lossis cov khoom xyaw yam tsis muaj kev phiv tshuaj, ua kom muaj kev ruaj ntseg ntawm txheej txheej.
Kev ua tau zoo ntawm kev tsim kho: HPMC tuaj yeem txhim kho qhov fluidity thiab kis tau ntawm cov txheej txheem, xyuas kom meej tias cov txheej txheem sib npaug ntawm qhov chaw ntawm lub substrate, thiab txhim kho nws cov adhesion.
Txhim kho qhov yooj yim thiab ua haujlwm ntev ntawm cov txheej: Cov yeeb yaj kiab-tsim ntawm HPMC tuaj yeem txhim kho qhov yooj yim ntawm txheej txheej, ua rau nws tsis tshua muaj kev tawg lossis tev tawm thaum raug quab yuam lossis ib puag ncig hloov pauv, thiab txuas ntxiv lub neej kev pab cuam ntawm txheej.
Kev tiv thaiv ib puag ncig: HPMC yog cov khoom tsis muaj tshuaj lom thiab tsis muaj teeb meem polymer uas ua tau raws li cov kev xav tau ntawm kev lag luam niaj hnub txheej rau kev tiv thaiv ib puag ncig thiab kev noj qab haus huv.
Raws li cov khoom siv ntxiv, HPMC yog siv hauv cov txheej txheem, tshwj xeeb tshaj yog txhawm rau txhim kho adhesion. Los ntawm nws cov thickening, ncua kev kawm ntawv, zaj duab xis-tsim thiab lwm yam dej num, HPMC tuaj yeem txhim kho adhesion ntawm txheej txheej thiab txhim kho tag nrho cov zoo thiab kav ntev ntawm cov txheej. Nrog kev nce qib ntawm cov txheej txheem thev naus laus zis tsis tu ncua, daim ntawv thov kev cia siab ntawm HPMC yuav dav dua thiab nws yuav txuas ntxiv ua lub luag haujlwm tseem ceeb hauv cov txheej txheem sib txawv.
Post lub sij hawm: Oct-18-2024