HPMC (Hydroxypropyl methylcellulose)yog ib hom dej-soluble cellulose derivative, uas yog dav siv nyob rau hauv kev tsim kho, tshwj xeeb tshaj yog nyob rau hauv kev hloov kho ntawm pob zeb. Nws muaj ntau yam zoo heev, xws li thickening, dej tuav, thiab txhim kho rheology. Nws tuaj yeem txhim kho kev ua haujlwm tau zoo thiab ua haujlwm ntev ntawm cov pob zeb, thiab tswj kev ua haujlwm ruaj khov nyob rau hauv ib puag ncig sib txawv.
1. Cov yam ntxwv tseem ceeb thiab kev siv ntawm HPMC
HPMC tau txais los ntawm kev hloov kho tshuaj ntawm cov cellulose ntuj, nrog rau cov dej solubility zoo thiab cov yeeb yaj kiab zoo heev. Nws lub luag haujlwm tseem ceeb yog txhawm rau txhim kho lub cev cov khoom ntawm pob zeb los ntawm kev tsim cov tshuaj colloidal ruaj khov. Hauv pob zeb, HPMC feem ntau yog siv los ua ib qho ntxiv los txhim kho nws txoj haujlwm, txhim kho nws cov dej tsis kam, thiab txo qhov porosity, yog li txhim kho kev ua haujlwm ntev ntawm pob zeb.
2. Mechanism ntawm kev txiav txim ntawm HPMC hauv pob zeb
2.1 Txhim kho kev ua haujlwm ntawm pob zeb
HPMC muaj cov nyhuv thickening. Tom qab ntxiv qhov tsim nyog ntawm HPMC rau pob zeb, nws tuaj yeem txhim kho qhov adhesion thiab fluidity ntawm pob zeb. Los ntawm kev tsim ib qho kev faib khoom sib xws, HPMC tuaj yeem txo qhov kev sib cuam tshuam ntawm cov cement particles thiab ua rau lawv zoo ib yam thaum lub sij hawm sib tov. Nyob rau hauv txoj kev no, nws tuaj yeem tsis tsuas yog txhim kho kev ua haujlwm ntawm pob zeb, tab sis kuj zam cov nag lossis daus ntawm cov cement hais thaum lub sijhawm tsim kho, kom ntseeg tau tias kev tsim kho zoo ntawm pob zeb.
2.2 Txhim kho qhov ua tau zoo ntawm cov tshuaj tiv thaiv dej
Lub durability ntawm pob zeb yog feem ntau ze ze rau qhov degree ntawm nws cov tshuaj tiv thaiv hydration. Raws li qhov tsim nyog piv ntawm cov cement rau dej, HPMC tuaj yeem ua kom cov dej khaws cia, ua kom cov dej ntws qeeb qeeb, thiab muab cov cement nrog lub voj voog ntev dua. Qhov no pab cov cement particles kom muaj kev cuam tshuam nrog dej, txhawb kev tsim cov cement pob zeb, thiab txhim kho qhov ceev thiab compressive lub zog ntawm pob zeb, yog li txhim kho lub durability ntawm pob zeb.
2.3 Txhim kho impermeability
Qhov porosity thiab pore loj hauv pob zeb ncaj qha cuam tshuam rau nws cov impermeability. Vim tias HPMC muaj qhov nqus dej zoo thiab khaws cia dej, nws tuaj yeem tsim cov txheej txheem dej tsis sib xws hauv cov pob zeb kom tiv thaiv kom tsis txhob poob dej sai. Los ntawm kev txhim kho microstructure ntawm pob zeb, HPMC tuaj yeem txo cov naj npawb thiab cov porosity ntawm capillaries, yog li txhim kho cov impermeability thiab te kuj ntawm cov pob zeb. Cov yam ntxwv no tseem ceeb tshwj xeeb tshaj yog nyob rau thaj tsam txias, vim nws tuaj yeem tiv thaiv cov ntaub ntawv cement-based los ntawm kev tawg vim yog qhov cuam tshuam khov-thaw thiab txhim kho cov kab nrib pleb thiab kav ntev ntawm cov pob zeb.
2.4 Txhim kho cov khoom tiv thaiv kev laus ntawm pob zeb
Nyob rau tib lub sijhawm, pob zeb yuav muaj kev ntxhov siab ib puag ncig, suav nrog kev hloov pauv kub, av noo hloov pauv, thiab tshuaj lom neeg yaig, uas yuav ua rau muaj kev laus. HPMC tuaj yeem txhim kho lub peev xwm tiv thaiv kev laus ntawm pob zeb los ntawm kev txhim kho nws cov microstructure. Tshwj xeeb tshaj yog, HPMC tuaj yeem ua kom cov dej hauv cov pob zeb ua kom muaj zog, ua kom cov dej tsis txaus ntawm cov cement, yog li txo qhov tawg ntawm cov cement pob zeb thiab ncua cov txheej txheem kev laus ntawm cov pob zeb. Tsis tas li ntawd, HPMC tseem tuaj yeem ua kom qeeb ntawm kev nkag mus rau cov ntsev thiab cov khoom tsis zoo rau hauv cov pob zeb, ntxiv dag zog rau cov pob zeb ua haujlwm.
2.5 Txhim kho cov tshuaj erosion tsis kam ntawm pob zeb
Hauv thaj chaw muaj kev lag luam, ib puag ncig hauv hiav txwv lossis lwm thaj chaw uas muaj cov tshuaj corrosive, cov pob zeb feem ntau raug rau cov khoom corrosive xws li acids, alkalis, thiab chloride ions. HPMC pab txo qis kev sib cuag ntawm cov tshuaj no thiab cov pob zeb ua ke thiab txo lawv cov kev yaig los ntawm kev tiv thaiv zaj duab xis uas nws tsim. Nyob rau tib lub sijhawm, HPMC tuaj yeem txhim kho qhov compactness ntawm pob zeb, txo qhov porosity, ntxiv txo txoj kev nkag mus ntawm cov khoom tsis zoo, thiab txhim kho corrosion kuj ntawm pob zeb.
3. Cov teebmeem tshwj xeeb ntawm HPMC rau kev ua haujlwm ruaj khov
3.1 Txhim kho khov-thaw tsis kam
Cov pob zeb yuav cuam tshuam los ntawm kev khov-thaw mus rau hauv cov huab cua txias, ua rau tawg thiab txo lub zog. HPMC tuaj yeem txhim kho nws qhov khov-thaw tiv thaiv los ntawm kev txhim kho microstructure ntawm pob zeb. Los ntawm kev txo cov porosity thiab nce qhov ntom ntawm cov pob zeb, HPMC pab txo cov dej tuav thiab txo kev puas tsuaj los ntawm kev khov kho. Tsis tas li ntawd, HPMC txhim kho qhov impermeability ntawm pob zeb, ua kom nws tiv taus dej nkag mus rau hauv lub voj voog khov-thaw, yog li txhim kho qhov ua tau zoo ntawm cov pob zeb.
3.2 Txhim kho sulfate tsis kam
Sulfate yaig yog ib qho tseem ceeb ntawm kev hem thawj rau kev ua kom ruaj khov, tshwj xeeb tshaj yog nyob rau hauv ntug dej hiav txwv lossis thaj chaw muaj kev lag luam. HPMC tuaj yeem txhim kho cov pob zeb sulfate tsis kam, tiv thaiv kev nkag mus ntawm cov tshuaj xws li sulfates los ntawm kev txo cov porosity thiab txhim kho impermeability. Tsis tas li ntawd, qhov sib ntxiv ntawm HPMC tuaj yeem txhawb kev sib sau ua ke ntawm cov qauv sab hauv ntawm cov khoom siv cement, ua rau nws nyuaj rau sulfate ions nkag mus thiab hnov mob nrog calcium aluminate hauv cov cement, yog li txo qhov nthuav dav thiab tawg los ntawm qhov no.
3.3 Txhim kho lub sij hawm ntev
Lub sij hawm ntev ntawm kev ua vaj tse feem ntau cuam tshuam los ntawm ib puag ncig sab nraud, xws li los nag, kev hloov pauv huab cua, thiab tshuaj yaig. HPMC tuaj yeem txuas txoj haujlwm lub neej ntawm cov pob zeb ua los ntawm kev txhim kho qhov ceev ceev thiab condermeability ntawm cov kub thiab txias, av noo, thiab salinity. Nws tuaj yeem txhim kho qhov ua tau zoo ntawm cov pob zeb hauv kev siv mus ntev los ntawm kev txo cov dej evaporation, txo cov porosity, thiab txhim kho cov tshuaj lom neeg ruaj khov.
Raws li ib qho kev hloov kho pob zeb zoo,HPMCtuaj yeem txhim kho qhov ua tau zoo ntawm cov pob zeb los ntawm kev txhim kho kev ua haujlwm ntawm pob zeb, txhim kho cov tshuaj tiv thaiv hydration, txhim kho impermeability thiab tiv thaiv cov tshuaj yaig. Hauv daim ntawv thov kev tsim kho yav tom ntej, HPMC xav kom dhau los ua cov khoom tseem ceeb rau kev txhim kho kev ruaj ntseg mus ntev thiab kev ntseeg siab ntawm cov vaj tse pob zeb. Nrog rau kev nce qib ntawm kev tshawb fawb thiab thev naus laus zis tsis tu ncua, kev thov ntawm HPMC hauv kev ua vaj tse yuav nthuav dav ntxiv, pab txhawb ntxiv rau kev txhim kho kev tsim kho kom ruaj khov.
Post lub sij hawm: Nov-08-2024