HydroxyPropyyl methylulose (HPMC) yog cov tsis-ionic cellulose ishet dav siv hauv cov ntaub ntawv hauv tsev, tshwj xeeb tshaj yog cov tshuaj khib thiab plaster. Raws li kev ntxiv, HPMC tuaj yeem txhim kho ntau yam khoom ntau ntawm cov ntaub ntawv no, suav nrog kev ua haujlwm, tso dej tsis kam, thiab lwm yam.
1. Tshuaj lom neeg thiab cov qauv ntawm HPMC
HPMC yog ib nrab hluavtaws polymer tau los ntawm kev kho cov pawg hydroxyl ntawm cov kws me ntawm methylation thiab hydroxyprorepation. Nws cov qauv theem pib yog cov piam thaj, uas txuas nrog los ntawm β-1,4-glycosidic bonds. Cov saw ntev ntawm cellulose muab nws zoo zaj duab xis-ua thiab nplaum cov khoom, thaum cov lus qhia ntawm methyl thiab hydroxypropropyl txhim kho nws cov solubility thiab ruaj khov.
Tus qauv tshuaj ntawm HPMC muab nws cov yam ntxwv hauv qab no:
Dej solubility: nws tuaj yeem yaj sai nyob rau hauv dej txias los tsim cov kua pob tshab kua.
Viscosity Hloov: Kev daws ntawm HPMC muaj cov tuaj yeem kho tau, uas nyob ntawm nws cov molecular hnyav thiab kev xav tau.
Stability: Nws yog ruaj khov rau cov kua qaub thiab cov hauv paus thiab tuaj yeem tswj nws qhov kev ua tau zoo tshaj qhov dav dav.
2. Mechanisms ntawm HPMC txhawm rau txhim kho kev ua tshuaj cug thiab plaster
(2.1). Txhim Kho Cov Khoom Siv Dej
Dej khaws cia yog hais txog kev muaj peev xwm cug lossis plaster los khaws dej, uas yog qhov tseem ceeb rau cov txheej txheem cement thiab cov txheej txheem tawv. HPMC txhim kho cov dej khaws cia los ntawm cov txheej txheem hauv qab no:
Zaj duab xis-ua cov nyhuv: HPMC ua cov yeeb yaj kiab nyias nyias nyob rau hauv colut lossis plaster, qeeb qeeb ntawm evaporation tus nqi ntawm dej.
Molecular dej nqus: HPMC lwg me me tuaj yeem nqus tau cov dej loj loj, txo cov dej kom tsawg thaum kev tsim kho thaum lub sijhawm kev tsim kho.
Cov dej cia siab pab kom kom cov dej khov kho hydrate, yog li kev txhim kho lub zog thiab kev sib khi ntawm cug cug thiab plaster. Tsis tas li ntawd, nws tseem yuav txo qhov kev tsim ntawm cov nraus uas tshwm sim los ntawm kev poob ntau dhau.
(2.2). Txhim Kho Kev Ua Haujlwm
Kev ua haujlwm ua haujlwm yog hais txog kev ua haujlwm ntawm cug thiab plaster nyob rau txheej txheem tsim kho, xws li fluidity thiab ua haujlwm. Cov txheej txheem uas HPMC txhim kho kev ua haujlwm muaj xws li:
Txhim kho cov plasticity: HPMC muab covricium zoo, muab cov dej sib xyaw kom zoo dua thiab zoo nkauj.
Kev tiv thaiv kev ceev xwm thiab cais cov nyhuv ntawm HPMC pab tswj hwm ib qho kev faib tawm, tiv thaiv delamination, tiv thaiv kev sib cais lossis sib cais rau hauv cov tshuaj khib nyiab lossis plaster.
Qhov no ua rau cov tshuaj khib lossis plaster yooj yim dua los ua haujlwm nrog thaum lub sijhawm kev tsim kho, tso cai rau ntau daim ntawv thov thiab saws, txo qhov tau pov tseg thiab ua haujlwm.
(2.3). Nce tawg
Tshuaj khib thiab plaster yuav tawg vim ntim shrinkage thaum ua kom tawv tawv thaum tawv nqaij tawv, thiab HPMC pab txo cov xwm txheej no:
Yooj taus: tus qauv siv network tsim los ntawm HPMC hauv cov khoom siv tau cug cug thiab plaster, yog li nqus thiab thim kev ntxhov siab.
Uniform kom qhuav: vim HPMC muab cov dej ua kom zoo, dej tuaj yeem tso tawm kom covyees, txo cov ntim hloov thaum ziab.
Cov khoom no txo qhov ua tau ntawm cov nrib pleb thiab txhim kho lub zog ntawm cov khoom siv.
3. Piv txwv ntawm HPMC cov ntawv thov hauv tshuaj khib thiab Plaster
(3.1). Vuas nplaum nplaum
Nyob rau hauv cov nplais nplaum, HPMC muab cov khoom ntub dej zoo heev, tso cai rau cov vuas kom khov kho rau lub substrate thiab tswj kev tsim kho zoo.
(3.2). CUG SELFLING CUG
Kev txhaj tshuaj rau tus kheej HPMC cov dej siab khaws cia thiab Viscosososity Haum tau lub peev xwm pab ua kom tiav cov kev xav tau no, ua rau muaj qhov chaw du.
3.3). Kua nplaum dawb ua phab ntsa
HPMC nce cov nplaum thiab tawg tawm tsam ntawm plaster, tshwj xeeb tshaj yog nyob rau sab nrauv plastering daim ntawv thov, thiab tuaj yeem tiv thaiv cov tawg thiab ntog tshwm sim los ntawm ntau yam ib puag ncig.
4. Kev ceev faj rau kev siv HPMC
(4.1). Kev siv
Tus nqi ntawm HPMC siv nyob rau hauv colle thiab plaster feem ntau yog ib feem me me nyob rau hauv cov nqe lus ntawm qhov hnyav feem pua, xws li 0.1% mus rau 0.5%. HPMC ntau dhau yuav ua rau muaj viscosity ntau dhau thiab cuam tshuam; Tsawg heev yuav ua rau nws nyuaj rau txhim kho kev ua tau zoo.
(4.2). Sib xyaw nrog lwm cov kev sib ntxiv
Thaum siv HPMC, nws yog ib qho yuav tsum tau xav tau compatibilitives nrog rau lwm cov tshuaj tiv thaiv dej sib txawv, thiab lwm yam) kom paub tseeb tias qhov kev ua tau zoo ntawm cov khoom siv tau cuam tshuam.
Raws li cov tshuaj tseem ceeb ntxiv, daim ntawv thov ntawm HPMC hauv tshuaj khib thiab plaster tseem txhim kho nws cov dej khaws cia, ua haujlwm thiab tawg tsis kam. Cov kev txhim kho no tsis yog txhim kho cov nyhuv kev tsim kho thiab cov khoom siv zoo, tab sis kuj txhim kho lub durability thiab kev ntseeg tau ntawm qhov project. Hauv cov ntawv thov tshwj xeeb, los ntawm kev hloov kho cov tshuaj thiab piv ntawm HPMC, cov kev ua tau zoo ntawm cug thiab plaster tuaj yeem ua tau zoo.
Lub Sijhawm Post: Feb-17-2025