Hydroxypropyl Methylcellulose (HPMC) yog cov dej-soluble polymer uas siv dav hauv cov khoom siv hauv tsev, tshwj xeeb tshaj yog cov cement-raws li cov nplaum nplaum. Cov khoom siv tshuaj lom neeg tshwj xeeb thiab cov khoom siv lub cev ntawm HPMC ua rau nws ua lub luag haujlwm tseem ceeb hauv kev txhim kho cov adhesion, kev tsim kho, thiab ua haujlwm ntev ntawm cov nplais nplaum.
(1) Kev paub txog HPMC
1. Cov qauv tshuaj ntawm HPMC
HPMC yog cellulose derivative tau los ntawm chemically modifying natural cellulose. Nws cov qauv yog tsim los ntawm methoxy (-OCH₃) thiab hydroxypropoxy (-CH₂CHOHCH₃) pab pawg hloov qee pawg hydroxyl ntawm cov saw cellulose. Cov qauv no muab HPMC zoo solubility thiab muaj peev xwm hydration.
2. Lub cev muaj zog ntawm HPMC
Solubility: HPMC tuaj yeem yaj hauv dej txias los tsim cov kua dej ntshiab colloidal thiab muaj dej zoo thiab muaj peev xwm thickening.
Thermogelation: HPMC cov tshuaj yuav tsim ib lub gel thaum cua sov thiab rov qab mus rau lub xeev ua kua tom qab txias.
Kev ua haujlwm saum npoo: HPMC muaj cov dej num zoo hauv kev daws teeb meem, uas pab tsim kom muaj cov qauv npuas ruaj khov.
Cov khoom tshwj xeeb ntawm lub cev thiab tshuaj lom neeg no ua rau HPMC yog cov khoom siv zoo tshaj plaws rau kev hloov kho cov cement-raws li cov nplaum nplaum.
(2) Mechanism ntawm HPMC txhim kho kev ua haujlwm ntawm cov cement-raws li cov nplaum nplaum
1. Txhim kho dej tuav
Lub hauv paus ntsiab lus: HPMC tsim cov qauv sib txuas sib txuas hauv cov tshuaj, uas tuaj yeem kaw cov dej noo zoo. Lub peev xwm tuav dej no yog vim muaj ntau pawg hydrophilic (xws li pawg hydroxyl) hauv HPMC molecules, uas tuaj yeem nqus tau thiab khaws cov dej noo ntau.
Txhim kho adhesion: Cement-raws li pobzeb adhesives yuav tsum tau noo noo los koom rau hauv cov tshuaj tiv thaiv hydration thaum lub sij hawm hardening txheej txheem. HPMC tswj xyuas qhov muaj dej noo, tso cai rau cov cement kom tag nrho hydrate, yog li txhim kho cov nplaum ntawm cov nplaum.
Txuas lub sijhawm qhib: Kev tuav dej tiv thaiv cov nplaum los ntawm kev ziab sai sai thaum tsim kho, ncua sij hawm hloov kho rau cov pobzeb tso.
2. Txhim kho kev tsim kho kev ua haujlwm
Lub hauv paus ntsiab lus: HPMC muaj cov nyhuv thickening zoo, thiab nws cov molecules tuaj yeem tsim cov qauv zoo li lub network hauv cov kua dej, yog li ua kom cov viscosity ntawm cov tshuaj.
Txhim kho cov cuab yeej los tiv thaiv sagging: Lub thickened slurry muaj cov cuab yeej los tiv thaiv sagging zoo dua thaum lub sij hawm tsim kho, kom cov vuas tuaj yeem nyob ruaj khov nyob rau hauv txoj hauj lwm predetermined thaum lub sij hawm paving txheej txheem thiab yuav tsis swb vim lub ntiajteb txawj nqus.
Txhim kho fluidity: Qhov tsim nyog viscosity ua rau cov nplaum yooj yim rau kev thov thiab sib kis thaum siv, thiab tib lub sijhawm muaj kev ua haujlwm zoo, txo qhov nyuaj ntawm kev tsim kho.
3. Txhim khu kev ruaj khov
Lub hauv paus ntsiab lus: HPMC txhim kho cov dej tuav thiab ua kom zoo ntawm cov nplaum, yog li txhim kho lub zog ntawm cov cement-raws li cov nplaum nplaum.
Txhim kho kev sib raug zoo zog: Lub siab hydrated cement substrate muab cov adhesion muaj zog dua thiab tsis tuaj yeem poob los yog tawg thaum siv mus ntev.
Txhim khu kev tiv thaiv kab mob: Kev tuav dej zoo kom tsis txhob muaj qhov loj me ntawm cov nplaum thaum lub sijhawm ziab, yog li txo qhov teeb meem tawg los ntawm shrinkage.
(3) Kev sim cov ntaub ntawv txhawb nqa
1. Kev sim ntsuas dej
Cov kev tshawb fawb tau pom tias cov dej tuav tus nqi ntawm cov cement-raws li cov nplaum nplaum nrog qhov sib ntxiv ntawm HPMC tau zoo dua. Piv txwv li, ntxiv 0.2% HPMC rau cov nplaum tuaj yeem ua kom cov dej tuav tau ntawm 70% mus rau 95%. Qhov kev txhim kho no yog qhov tseem ceeb rau kev txhim kho lub zog sib txuas thiab durability ntawm cov nplaum.
2. Kev ntsuas viscosity
Tus nqi ntawm HPMC ntxiv muaj qhov cuam tshuam loj rau viscosity. Ntxiv 0.3% HPMC rau cov cement-raws li cov nplaum nplaum tuaj yeem ua kom cov viscosity ntau zaus, kom ntseeg tau tias cov nplaum nplaum muaj kev ua haujlwm zoo thiab kev tsim kho.
3. Bond lub zog kuaj
Los ntawm kev sib piv cov kev sim, nws tau pom tias lub zog sib txuas ntawm cov vuas thiab substrates ntawm cov nplaum uas muaj HPMC yog qhov zoo dua li cov nplaum uas tsis muaj HPMC. Piv txwv li, tom qab ntxiv 0.5% HPMC, lub zog sib txuas tuaj yeem nce li ntawm 30%.
(4) Daim ntawv thov piv txwv
1. Tso cov vuas hauv pem teb thiab cov vuas phab ntsa
Nyob rau hauv qhov tseeb tso ntawm cov vuas hauv pem teb thiab phab ntsa vuas, HPMC-txhim kho cov cement-raws li pobzeb adhesives pom zoo kev tsim kho thiab kev sib raug zoo ntev. Thaum lub sij hawm kev tsim kho, cov nplaum nplaum tsis yooj yim kom poob dej sai sai, kom ntseeg tau qhov smoothness ntawm kev tsim kho thiab lub tiaj tus ntawm cov vuas.
2. Sab nrauv phab ntsa rwb thaiv tsev
HPMC-enhanced adhesives kuj tau siv dav hauv cov kab hluav taws xob sab nraud. Nws cov dej tuav tau zoo thiab adhesion ua kom muaj kev sib raug zoo ntawm cov rwb thaiv tsev thiab cov phab ntsa, yog li txhim kho cov kav ntev thiab kev ruaj ntseg ntawm cov phab ntsa sab nraud.
Daim ntawv thov ntawm HPMC nyob rau hauv cov cement-raws li pobzeb adhesives ho txhim kho cov kev ua tau zoo ntawm cov nplaum. Los ntawm kev txhim kho cov dej tuav, txhim kho kev tsim kho kev ua haujlwm thiab txhim kho cov kav ntev, HPMC ua rau cov cement-raws li cov nplaum nplaum tsim nyog rau kev tsim kho niaj hnub no. Nrog rau kev txhim kho thev naus laus zis thiab kev xav tau ntau ntxiv rau cov khoom siv hauv tsev ua tau zoo, daim ntawv thov kev cia siab ntawm HPMC yuav dav dua.
Post lub sij hawm: Jun-26-2024