Hydroxypropyl Methylcellulose (HPMC) yog non-ionic cellulose ether siv dav hauv cov khoom siv hauv tsev, zaub mov, tshuaj pleev ib ce, tshuaj thiab lwm yam haujlwm. Nws yog tsim los ntawm kev hloov kho tshuaj ntawm cellulose. Nws feem ntau tshwm li cov hmoov dawb los yog dawb dawb thiab yooj yim soluble hauv dej los tsim cov pob tshab lossis me ntsis turbid colloidal tov.
Cov qauv tshuaj thiab cov khoom ntawm HPMC
HPMC yog tau los ntawm methylation (qhia cov pab pawg methoxyl, -OCH₃) thiab hydroxypropylation (qhia cov pab pawg hydroxypropoxyl, -CH₂CHOHCH₃) ntawm pawg hydroxyl (-OH) ntawm cellulose. Cov methoxy thiab hydroxypropoxy moieties nyob rau hauv nws cov qauv txiav txim siab nws solubility thiab viscosity zog.
HPMC muaj cov yam ntxwv tseem ceeb hauv qab no:
Dej solubility: HPMC tuaj yeem yaj sai sai hauv dej txias los tsim cov kua dej viscosity siab.
Thermal gelation: HPMC cov kev daws teeb meem yuav tsim cov gels thaum cua sov.
Stability: Nws nyob ruaj khov nyob rau hauv ob qho tib si acidic thiab alkaline tej yam kev mob thiab tsis yooj yim degraded.
Thickening: tuaj yeem ua kom cov viscosity ntawm aqueous tov.
Zaj duab xis-forming zog: tuaj yeem tsim cov duab pob tshab thiab muaj zog.
Lubricity: tuaj yeem ua lub luag haujlwm lubricating hauv qee cov qauv.
Lub luag haujlwm ntawm HPMC hauv cov nplais nplaum
Pobzeb nplaum yog cov khoom siv hauv tsev siv los tso cov vuas luaj ceramic, thiab nws qhov kev ua tau zoo cuam tshuam ncaj qha rau qhov zoo thiab kav ntev ntawm cov paving. HPMC ua lub luag haujlwm tseem ceeb hauv cov nplaum nplaum, thiab nws qhov kev ua tau zoo yog raws li hauv qab no:
1. Txhim kho kev ua haujlwm
HPMC tuaj yeem ua kom lub sijhawm ua haujlwm ntawm cov pobzeb nplaum, ua kom yooj yim rau cov neeg ua haujlwm tsim kho kom kho qhov chaw ntawm cov vuas hauv ib lub sijhawm. Qhov no yog vim HPMC tuaj yeem ua kom cov dej khaws cia ntawm cov nplaum, yog li ncua cov dej evaporation.
2. Txhim khu kev tuav dej
Kev tuav dej yog ib qho ntawm cov khoom tseem ceeb ntawm cov nplais nplaum, uas txiav txim siab cov nplaum nplaum muaj peev xwm khaws cov dej noo thaum lub sijhawm kho. HPMC tiv thaiv kev poob dej sai sai los ntawm kev tsim cov yeeb yaj kiab dej khov thiab ua kom cov nplaum muaj dej txaus rau cov tshuaj tiv thaiv dej ua ntej kho. Cov cuab yeej no yog qhov tseem ceeb tshwj xeeb los xyuas kom muaj zog ntawm kev sib raug zoo thiab tiv thaiv kev tawg.
3. Txhim kho kev sib raug zoo
Los ntawm nws cov yeeb yaj kiab tsim thiab ua kom tuab, HPMC ua rau cov nplaum ua kom zoo dua rau ntawm cov vuas luaj ceramic thiab substrates, yog li txhim kho lub zog sib txuas. Nyob rau tib lub sijhawm, HPMC kuj tuaj yeem txhim kho qhov kev ua haujlwm ntawm cov nplaum nplaum los tiv thaiv cov vuas los ntawm kev hloov pauv thaum lub sijhawm tso.
4. Txhim kho kev tsim kho kev ua haujlwm
Txij li thaum HPMC tuaj yeem txhim kho qhov sib xws thiab rheology ntawm cov nplais nplaum, cov nplaum tuaj yeem sib kis tau tusyees thaum lub sij hawm tsim kho, ua rau kev tsim kho ntau zog-txuag. Tsis tas li ntawd, nws lubricity tuaj yeem ua rau cov txheej txheem paving smoother thiab txo cov teeb meem kev tsim kho.
Lwm yam kev siv ntawm HPMC hauv kev tsim kho chemistry
Ntxiv nrog rau nws siv hauv cov nplais nplaum, HPMC muaj ntau yam kev siv hauv kev tsim kho chemistry:
1. Cement mortar
Hauv cov cement-based mortars, HPMC yog siv los ua cov thickener thiab dej-retaining agent. Nws tuaj yeem txhim kho kev tsim kho ntawm mortar, ua kom nws smoother thiab yooj yim rau kev thov. Nws tseem tuaj yeem txuas ntxiv lub sijhawm qhib thiab txhim kho lub zog thiab ua haujlwm ntev tom qab teeb tsa thiab tawv.
2. Plastering system
Hauv plastering mortars, HPMC txhim kho kev tsim kho kev ua haujlwm thiab kev tuav dej, ua rau cov mortar zoo dua rau kev tsim kho nyob rau hauv qhov kub thiab txias. Tsis tas li ntawd, HPMC tuaj yeem txo qhov shrinkage thiab tawg thaum lub sij hawm plastering.
3. Self-leveling mortar
Self-leveling mortar yuav tsum tsis tshua muaj siab fluidity thiab adhesion. Los ntawm kev tswj xyuas qhov sib xws thiab rheology ntawm lub mortar, HPMC ua rau nws tus kheej-leveling mortar yuav cia li kis tau thaum lub sij hawm tsim kho los tsim ib tug du nto, txo cov kev xav tau ntawm phau ntawv kev cuam tshuam.
4. Sab nrauv phab ntsa rwb thaiv tsev
Nyob rau sab nrauv phab ntsa rwb thaiv tsev, HPMC ua hauj lwm raws li cov thickening thiab dej-retaining tivthaiv ntawm lub binder, kom ntseeg tau tias lub rwb thaiv tsev board yuav ruaj khov adhered rau phab ntsa thaum txhim kho huab cua tsis kam thiab durability ntawm lub system.
Kev ceev faj rau kev siv HPMC
Txawm hais tias HPMC muaj ntau qhov zoo, cov ntsiab lus hauv qab no yuav tsum tau sau tseg hauv cov ntawv thov siv tau:
Kev tswj kev noj tshuaj: Kev noj ntau dhau ntawm HPMC tuaj yeem ua rau cov kua nplaum ntawm cov nplaum txo qis thiab cuam tshuam rau kev tsim kho. Cov koob tshuaj tsim nyog yuav tsum tau hloov kho raws li cov qauv xav tau.
Uniform dispersion: Thaum tsim cov nplaum nplaum, HPMC yuav tsum tau tawg tag nrho kom ntseeg tau tias nws qhov kev ua tau zoo tuaj yeem sib npaug. Nws feem ntau yog yaj hauv dej ua ntej thiab tom qab ntawd ntxiv lwm cov khoom xyaw ntxiv.
Kev cuam tshuam ib puag ncig: HPMC kuj tseem ceeb rau qhov kub thiab txias, thiab qhov cuam tshuam ntawm qhov sib txawv ntawm kev tsim kho yuav tsum tau txiav txim siab thaum tsim cov qauv.
Lub luag haujlwm ntawm HPMC hauv pobzeb adhesives thiab lwm yam khoom siv tshuaj lom neeg tsis tuaj yeem tsis quav ntsej. Nws cov dej tuav tau zoo heev, thickening, adhesion thiab txhim kho kev tsim kho vaj tse tau ua kom zoo dua ntawm cov khoom siv hauv tsev thiab kev tsim kho kom zoo. Nrog rau kev tsim qauv tsim thiab daim ntawv thov, HPMC tuaj yeem txhim kho qhov ua tau zoo thiab kev ruaj ntseg ntev ntawm kev tsim kho.
Post lub sij hawm: Jun-25-2024