Lub npe Suav ntawm HPMC yog hydroxypropyl methylulose. Nws tsis yog-ionic thiab feem ntau yog siv los ua cov dej-khaws cov neeg sawv cev hauv cov tshuaj khib nyiab qhuav. Nws yog qhov feem ntau siv dej-khaws cov khoom siv hauv kab cug.
Cov txheej txheem ntau lawm ntawm HPMC feem ntau yog cov khoom lag luam polysaccharide uas ua los ntawm kev sib tw thiab ci ntsa iab ntawm cov paj rwb fiber ntau (hauv tsev). Nws tsis tau them nqi nws tus kheej, tsis muaj kev tawm tsam nrog cov nqi them rau cov khoom siv loj, thiab muaj kev ua tau ruaj khov. Tus nqi kuj tseem qis dua lwm hom cellulose muaj kev hais ua neeg muaj kev hais ua, yog li nws tau siv dav hauv qhuav-mixeded cug.
Muaj nuj nqi ntawm hydroxypropylencellulose: nws tuaj yeem thicken cov tshuaj sib xyaw tshiab kom muaj cov viscosity thiab tiv thaiv cais. (Thickening) dej khaws cia kuj yog qhov tseem ceeb tshaj plaws, uas tau ua kom muaj cov tshuaj khib nyiab nyob rau hauv lub creattructed, cov khoom siv xis nyob kom muaj sijhawm ntau rau hydrate. (Dej khaws cia) Nws tau muaj huab cua-entraining cov khoom, uas tuaj yeem qhia cov kev hnav khaub ncaws thiab cov pa npuas zoo los txhim kho kev siv tshuaj khib.
Qhov siab tshaj lub viscosity ntawm hydroxypropyl methylculose ether, ua kom cov dej zoo dua. Viscosity yog qhov tseem ceeb parameter ntawm HPMC kev ua tau zoo. Tam sim no, sib txawv HPMC cov tuam ntxhab Siv cov qauv sib txawv thiab cov cuab yeej los ntsuas qhov viscosity ntawm HPMC. Cov hau kev tseem ceeb yog Haakerotovisovisko, Hoppller, Ubbelihde thiab Brookfield.
Rau tib cov khoom lag luam, cov viscosity tau ntsuas los ntawm cov qauv sib txawv yog qhov sib txawv heev, thiab qee tus txawm tau muaj ob npaug sib txawv. Yog li ntawd, thaum piv cov viscosity, nws yuav tsum tau nqa tawm ntawm tib txoj kev ntsuas, rotor, etcer hais txog particle loj, qhov zoo dua cov dej rov qab. Tom qab cov ntu loj ntawm cellulose ethows tuaj nkag mus rau hauv kev sib cuag nrog cov khoom los tiv thaiv cov roj av lwg me me los ntawm txuas ntxiv mus rau infiltrate. Qee lub sij hawm nws tsis tuaj yeem sib txawv dispersed thiab yaj txawm tias tom qab lub sij hawm ntev plhaw, sib sau cov huab nrog cov huab lossis agglomeration. Nws cuam tshuam heev ntawm cov dej tuav ntawm cellulose ether, thiab solubility yog ib qho ntawm cov cellulose ether.
Fineness tseem yog ib qho kev ua tau tseem ceeb ntsuas ntawm methyl cellulose ether. MC siv rau cov hmoov huv kom qhuav yuav tsum tau ua kom tau hmoov, nrog cov dej hauv dej qis, thiab 60% ntawm qhov me me kom tsawg dua 63um. Cov txiaj ntsig zoo rau cov solubility ntawm hydroxypropylopylulcellulose ether. Kev ntxhib feem ntau yog granular, thiab nws yog ib qho yooj yim kom yaj hauv dej yam tsis muaj agglomeration, tab sis nws tsis haum rau siv hauv cov hmoov av qhuav.
Hauv cov hmoov chot, MC tau tawg ntawm cov khoom siv cov txiv ntoo xws li ua kom zoo nkauj thiab ua kom zoo nkauj thiab tsw qab, thiab tsuas yog siv metyl cellulose agglomeration thaum sib xyaw nrog dej. Thaum MC tau ntxiv nrog dej kom yaj lub agglomerates, nws yog qhov nyuaj heev rau kev ntiab tawm thiab yaj. Ntxhoo Zoo ntawm MC tsis yog tsuas yog khib, tab sis kuj tseem txo lub zog ntawm lub tshuaj khib. Thaum xws li cov hmoov av qhuav tau thov rau hauv thaj chaw loj, tshuaj kho kom txo qis, thiab cov kab nrib pleb yuav tshwm sim vim kev kho tus nqi sib txawv. Rau cov tshuaj khib kab kuab nrog kev tsim kho tshuab, qhov yuav tsum muaj rau kev zoo kawg nkaus yog siab dua vim muaj lub sijhawm sib xyaw luv luv. Feem ntau hais lus, ntau dua cov viscosity, qhov zoo dua cov dej khaws cov nyhuv khaws cia. Txawm li cas los xij, qhov siab tshaj plaws viscosity thiab ntau dua cov molecular hnyav ntawm MC, cov kev coj ua tsis zoo rau lub zog thiab kev tsim kho ntawm lub tshuaj khib.
Qhov siab tshaj lub viscosity, qhov pom ntau ntxiv rau cov nyhuv tuab rau ntawm lub tshuaj khib, tab sis nws tsis ncaj ncaj ncaj. Qhov siab tshaj lub viscosity, ntau ntau ntau lub cug cug cug yuav ua, uas yog, thaum lub sijhawm tsim, nws yog manifested raws li straper thiab siab adhesion rau lub substrate. Tab sis nws tsis muaj txiaj ntsig zoo rau kev nce cov txheej txheem lub zog ntawm lub txiv ntoo qhuav nws tus kheej. Ntawd yog, thaum kev tsim kho, kev ua haujlwm los tiv thaiv tsis pom zoo tsis pom tseeb. Ntawm qhov tsis sib xws, qee qhov nruab nrab thiab qis viscosity tab sis hloov kho metyl cellulose cellulose kev ua tau zoo tshaj plaws hauv kev txhim kho lub zog ntawm cov tshuaj khib nyiab ntub dej.
Cov dej khaws cia ntawm HPMC kuj tseem cuam tshuam nrog qhov kub siv, thiab cov dej tuav tseg ntawm methyl cellulose nrog qhov kub ntawm kub. Txawm li cas los xij, hauv cov ntawv thov cov khoom siv tiag tiag, muab cov hmoov txhuam kom qhuav rau lub hnub sov Tshuaj Khib Dej Qhuav. Kev poob qis ntawm cov dej tuav cia ua rau pom tseeb tias ob qho tib si ua haujlwm thiab tawg tau cuam tshuam yog cuam tshuam rau cov khoom siv kub hauv qab no.
Hauv qhov no, methyl hydrotyl cellulose cellulose etheritive tam sim no tau txiav txim siab ua ntej thev naus laus zis ua ntej. Txawm hais tias tus nqi ntawm methyl hydrothethyl cellulose muaj nce (lub caij ntuj sov formula), kev ua haujlwm lub caij ntuj sov), kev ua haujlwm tsis tuaj yeem ua tau raws li qhov xav tau ntawm kev siv. Los ntawm qee qhov kev kho mob tshwj xeeb rau ntawm MC, xws li nce qib etherification, thiab lwm yam, kom nws tuaj yeem muab kev ua haujlwm zoo hauv qab.
Qhov ntau npaum li cas ntawm HPMC yuav tsum tsis txhob siab dhau, txwv tsis pub nws yuav ua rau cov dej khib nyiab, nws yuav cuam tshuam lub sijhawm ntev, uas yuav cuam tshuam rau kev tsim nyog. Txawv cov khoom lag luam txawv siv hpmc nrog cov viscosities sib txawv, thiab tsis txhob siv high-viscosity HPMC ua ke. Yog li ntawd, txawm hais tias hydroxypropal methylropen cov khoom yog qhov zoo, lawv tau qhuas thaum lawv siv tau zoo. Xaiv lub npe HPMC yog lub luag haujlwm tseem ceeb ntawm cov neeg ua haujlwm hauv kev lag luam. Tam sim no, ntau tus tswv lag luam tsis tau muaj ntau tus HPMC, thiab qhov zoo yog qhov tsis zoo heev. Thaum xaiv ib qho kev xaiv qee yam, chav kuaj yuav tsum ua txoj haujlwm zoo hauv kev sim kom ntseeg tau tias cov khoom siv tshuaj khib, thiab tsis txhob ua kom poob siab.
Lub Sijhawm Post: Lub Tsib Hlis-04-2023