1. Cov khoom tseem ceeb ntawm HPMC
Hydroxypropyl methylcellulose (HPMC)yog ib qho cellulose ether nonionic siv dav hauv cov ntaub ntawv siv hauv kev tsim kho, tshuaj, khoom noj, tshuaj pleev ib ce thiab lwm yam lag luam. Nws cov yam ntxwv tshwj xeeb ntawm lub cev thiab tshuaj lom neeg, xws li solubility, thickening, zaj duab xis-tsim thiab thermal gelation, ua rau nws yog ib qho khoom xyaw tseem ceeb hauv ntau daim ntawv thov kev lag luam. Kub yog ib qho ntawm cov yam tseem ceeb uas cuam tshuam rau kev ua tau zoo ntawm HPMC, tshwj xeeb tshaj yog nyob rau hauv cov nqe lus ntawm solubility, viscosity, thermal gelation thiab thermal stability.
2. Qhov cuam tshuam ntawm qhov kub thiab txias rau qhov solubility ntawm HPMC
HPMC yog ib qho polymer uas yaj tau yooj yim, thiab nws qhov solubility hloov pauv nrog qhov kub thiab txias:
Qhov kub qis (dej txias): HPMC yooj yim yaj hauv dej txias, tab sis nws yuav nqus dej thiab o thaum nws thawj zaug kov dej los ua cov khoom me me. Yog tias do tsis txaus, cov pob yuav tsim. Yog li ntawd, feem ntau nws raug pom zoo kom ntxiv HPMC qeeb qeeb thaum do kom txhawb kev sib kis zoo ib yam.
Kub nruab nrab (20-40 ℃): Hauv qhov kub no, HPMC muaj solubility zoo thiab viscosity siab, thiab nws tsim nyog rau ntau lub tshuab uas xav tau thickening lossis stabilization.
Kub siab (saum toj no 60 ° C): HPMC feem ntau yuav tsim cov gel kub ntawm qhov kub siab. Thaum qhov kub ncav cuag qhov kub gel tshwj xeeb, cov tshuaj yuav dhau los ua opaque lossis txawm tias coagulate, cuam tshuam rau cov nyhuv ntawm daim ntawv thov. Piv txwv li, hauv cov ntaub ntawv tsim kho xws li mortar lossis putty hmoov, yog tias qhov kub ntawm dej siab dhau, HPMC yuav tsis yaj zoo, yog li cuam tshuam rau qhov zoo ntawm kev tsim kho.
3. Cov nyhuv ntawm qhov kub thiab txias rau HPMC viscosity
Qhov viscosity ntawm HPMC raug cuam tshuam los ntawm qhov kub thiab txias:
Kub nce, viscosity txo qis: Qhov viscosity ntawm HPMC kua feem ntau txo qis nrog qhov kub nce. Piv txwv li, qhov viscosity ntawm qee yam kua HPMC yuav siab ntawm 20 ° C, thaum ntawm 50 ° C, nws cov viscosity yuav poob qis heev.
Kub txo qis, viscosity rov qab los: Yog tias cov tshuaj HPMC txias tom qab cua sov, nws cov viscosity yuav rov qab los ib nrab, tab sis nws yuav tsis tuaj yeem rov qab mus rau lub xeev pib tag nrho.
HPMC ntawm cov qib viscosity sib txawv coj tus cwj pwm txawv: HPMC uas muaj viscosity siab dua yog qhov rhiab heev rau kev hloov pauv kub, thaum HPMC uas muaj viscosity qis muaj viscosity hloov pauv tsawg dua thaum qhov kub hloov pauv. Yog li ntawd, nws yog qhov tseem ceeb tshwj xeeb los xaiv HPMC nrog viscosity zoo hauv cov xwm txheej thov sib txawv.
4. Qhov cuam tshuam ntawm qhov kub thiab txias rau qhov thermal gelation ntawm HPMC
Ib qho tseem ceeb ntawm HPMC yog thermal gelation, uas yog, thaum qhov kub nce mus txog qee qib, nws cov kua yuav hloov mus ua gel. Qhov kub no feem ntau hu ua qhov kub gelation. Ntau hom HPMC muaj qhov kub gelation sib txawv, feem ntau ntawm 50-80 ℃.
Hauv kev lag luam khoom noj thiab tshuaj, tus yam ntxwv no ntawm HPMC yog siv los npaj cov tshuaj tso tawm tas mus li lossis cov khoom noj colloids.
Hauv kev siv rau kev tsim kho, xws li cov cement mortar thiab putty hmoov, cov thermal gelation ntawm HPMC tuaj yeem khaws dej, tab sis yog tias qhov kub ntawm qhov chaw tsim kho siab dhau, gelation yuav cuam tshuam rau kev ua haujlwm tsim kho.
5. Qhov cuam tshuam ntawm qhov kub thiab txias rau qhov ruaj khov ntawm HPMC
Cov qauv tshuaj ntawm HPMC ruaj khov nyob rau hauv qhov kub thiab txias tsim nyog, tab sis kev raug kub ntev ntev yuav ua rau muaj kev puas tsuaj.
Kub siab luv luv (xws li cua sov tam sim ntawd mus rau saum 100 ℃): tej zaum yuav tsis cuam tshuam rau cov khoom siv tshuaj lom neeg ntawm HPMC, tab sis yuav ua rau muaj kev hloov pauv ntawm cov khoom siv lub cev, xws li viscosity txo qis.
Kub siab ntev (xws li cua sov tas mus li saum 90 ℃): yuav ua rau cov saw hlau molecular ntawm HPMC tawg, ua rau viscosity txo qis tsis rov qab, cuam tshuam rau nws cov thickening thiab cov khoom ua zaj duab xis.
Kub heev (ntau tshaj 200 ℃): HPMC yuav raug rhuav tshem los ntawm cua sov, tso cov tshuaj volatile xws li methanol thiab propanol, thiab ua rau cov khoom siv hloov xim lossis txawm tias carbonize.
6. Cov lus qhia rau daim ntawv thov rau HPMC hauv cov chaw kub sib txawv
Yuav kom muab kev ua si tag nrho rau kev ua tau zoo ntawm HPMC, yuav tsum tau ua raws li qhov chaw kub sib txawv:
Hauv qhov kub tsawg (0-10 ℃): HPMC yaj qeeb qeeb, thiab nws raug pom zoo kom yaj ua ntej hauv dej sov (20-40 ℃) ua ntej siv.
Hauv qhov kub thiab txias ib txwm muaj (10-40 ℃): HPMC muaj kev ua haujlwm ruaj khov thiab haum rau feem ntau daim ntawv thov, xws li cov tshuaj pleev xim, cov tshuaj khib nyiab, cov khoom noj thiab cov tshuaj ntxiv.
Hauv qhov chaw kub siab (saum toj no 40 ℃): Tsis txhob ntxiv HPMC ncaj qha rau hauv cov kua kub siab. Nws raug pom zoo kom yaj nws hauv dej txias ua ntej ua kom sov, lossis xaiv HPMC uas tiv taus kub siab kom txo qhov cuam tshuam ntawm thermal gelation rau daim ntawv thov.
Kub muaj qhov cuam tshuam loj rau qhov solubility, viscosity, thermal gelation thiab thermal stability ntawmHPMCThaum lub sijhawm thov, nws yog qhov tsim nyog los xaiv tus qauv thiab txoj kev siv HPMC raws li qhov kub tshwj xeeb kom ntseeg tau tias nws ua tau zoo tshaj plaws. Kev nkag siab txog qhov kub thiab txias ntawm HPMC tsis tsuas yog txhim kho cov khoom zoo xwb, tab sis kuj zam kev poob tsis tsim nyog los ntawm kev hloov pauv kub thiab txhim kho kev ua haujlwm zoo thiab cov txiaj ntsig kev lag luam.
Lub sijhawm tshaj tawm: Lub Peb Hlis-28-2025