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xov xwm

Viscosity Properties ntawm Hydroxypropyl Methyl Cellulose

Hydroxypropyl methylcellulose (HPMC) yog non-ionic, dej-soluble cellulose sib xyaw ether.Cov tsos mob yog dawb mus rau me ntsis daj hmoov los yog cov khoom siv granular, saj tsis qab, tsis muaj ntxhiab, tsis muaj tshuaj lom, tshuaj lom neeg ruaj khov, thiab yaj hauv dej los tsim cov kua nplaum, pob tshab thiab khov.Ib qho ntawm cov khoom tseem ceeb tshaj plaws ntawm hydroxypropyl methylcellulose hauv daim ntawv thov yog tias nws ua kom cov viscosity ntawm cov kua.Cov nyhuv thickening nyob ntawm qhov degree ntawm polymerization (DP) ntawm cov khoom, qhov concentration ntawm cellulose ether nyob rau hauv cov kua aqueous, shear npaum li cas, thiab cov tshuaj kub.Thiab lwm yam.

01

Cov kua hom HPMC aqueous tov

Feem ntau, qhov kev ntxhov siab ntawm cov kua hauv shear flow tuaj yeem qhia tau tias tsuas yog qhov kev ua haujlwm ntawm qhov shear rate ƒ (γ), tsuav nws tsis nyob ntawm lub sijhawm.Nyob ntawm daim ntawv ƒ(γ), cov kua dej tuaj yeem muab faib ua ntau hom, xws li: Newtonian kua, dilatant kua, pseudoplastic kua thiab Bingham cov kua yas.

Cellulose ethers tau muab faib ua ob pawg: ib qho yog non-ionic cellulose ether thiab lwm yam yog ionic cellulose ether.Rau rheology ntawm ob hom cellulose ethers.SC Naik et al.tau ua ib txoj kev tshawb fawb txog kev sib piv ntawm hydroxyethyl cellulose thiab sodium carboxymethyl cellulose daws.Cov txiaj ntsig tau pom tias ob qho kev daws teeb meem tsis yog ionic cellulose ether thiab ionic cellulose ether daws yog pseudoplastic.Flows, piv txwv li cov uas tsis yog-Newtonian ntws, mus rau Newtonian kua tsuas yog nyob rau hauv tsawg heev.Lub pseudoplasticity ntawm hydroxypropyl methylcellulose kua plays lub luag haujlwm tseem ceeb hauv daim ntawv thov.Piv txwv li, thaum siv nyob rau hauv coatings, vim lub shear thinning yam ntxwv ntawm aqueous tov, lub viscosity ntawm cov tshuaj txo nrog rau qhov nce ntawm shear npaum li cas, uas yog conducive mus rau lub uniform dispersion ntawm pigment hais, thiab kuj tsub kom lub fluidity ntawm txheej. .Cov nyhuv loj heev;Thaum so, lub viscosity ntawm cov tshuaj yog qhov loj, uas zoo tiv thaiv cov deposition ntawm pigment hais nyob rau hauv lub txheej.

02

HPMC Viscosity Test Method

Qhov taw qhia tseem ceeb los ntsuas cov nyhuv thickening ntawm hydroxypropyl methylcellulose yog qhov pom tseeb viscosity ntawm cov tshuaj aqueous.Cov kev ntsuas ntawm qhov pom tseeb viscosity feem ntau suav nrog txoj kev capillary viscosity, txoj kev tig viscosity thiab txoj kev poob pob viscosity.

qhov twg: yog qhov pom tseeb viscosity, mPa s;K yog qhov viscometer tas li;d yog qhov ntom ntawm cov qauv kev daws teeb meem ntawm 20/20 ° C;t yog lub sij hawm rau kev daws teeb meem los ntawm sab sauv ntawm lub viscometer mus rau hauv qab lub cim, s;Lub sij hawm uas tus qauv roj ntws los ntawm viscometer yog ntsuas.

Txawm li cas los xij, txoj kev ntsuas los ntawm capillary viscometer yog teeb meem ntau dua.Cov viscosities ntawm ntau cov cellulose ethers yog ib qho nyuaj rau kev soj ntsuam siv lub capillary viscometer vim hais tias cov kev daws teeb meem no muaj cov kab ntawm cov teeb meem insoluble uas tsuas yog kuaj tau thaum lub capillary viscometer raug thaiv.Yog li ntawd, feem ntau manufacturers siv viscometer rotational los tswj qhov zoo ntawm hydroxypropyl methylcellulose.Brookfield viscometers feem ntau siv nyob rau hauv txawv teb chaws, thiab NDJ viscometers yog siv nyob rau hauv Suav teb.

03

Kev cuam tshuam ntawm HPMC viscosity

3.1 Kev sib raug zoo nrog qib ntawm kev sib sau

Thaum lwm qhov tsis hloov pauv, qhov viscosity ntawm hydroxypropyl methylcellulose tov yog proportional rau qib ntawm polymerization (DP) los yog molecular hnyav los yog molecular saw ntev, thiab nce nrog qhov nce ntawm cov degree ntawm polymerization.Cov nyhuv no tau tshaj tawm nyob rau hauv cov ntaub ntawv ntawm cov qib qis ntawm polymerization dua li ntawm cov qib siab ntawm polymerization.

3.2 Kev sib raug zoo ntawm viscosity thiab concentration

Lub viscosity ntawm hydroxypropyl methylcellulose nce nrog qhov nce ntawm cov concentration ntawm cov khoom nyob rau hauv cov kua aqueous.Txawm tias ib qho kev hloov me me yuav ua rau muaj kev hloov pauv loj hauv viscosity.Nrog rau qhov nominal viscosity ntawm hydroxypropyl methylcellulose Cov nyhuv ntawm kev hloov ntawm cov tshuaj concentration ntawm cov viscosity ntawm cov tshuaj yog ntau thiab ntau pom tseeb.

3.3 Kev sib raug zoo ntawm viscosity thiab shear rate

Hydroxypropyl methylcellulose aqueous kua muaj cov cuab yeej ntawm shear thinning.Hydroxypropyl methylcellulose ntawm txawv nominal viscosity yog npaj rau hauv 2% aqueous tov, thiab nws viscosity ntawm txawv shear tus nqi yog ntsuas raws.Cov txiaj ntsig tau raws li hauv qab no Raws li pom hauv daim duab.Thaum qis shear npaum li cas, viscosity ntawm hydroxypropyl methylcellulose tov tsis hloov pauv loj.Nrog rau qhov nce ntawm shear npaum li cas, lub viscosity ntawm hydroxypropyl methylcellulose tov nrog siab dua nominal viscosity poob ntau pom tseeb, thaum cov tshuaj uas tsis muaj viscosity tsis txo kom pom tseeb.

3.4 Kev sib raug zoo ntawm viscosity thiab kub

Lub viscosity ntawm hydroxypropyl methylcellulose tov yog heev cuam tshuam los ntawm qhov kub thiab txias.Raws li qhov kub thiab txias, qhov viscosity ntawm cov tshuaj txo.Raws li pom nyob rau hauv daim duab, nws yog npaj rau hauv ib tug aqueous tov nrog ib tug concentration ntawm 2%, thiab qhov kev hloov ntawm lub viscosity nrog rau qhov nce ntawm kub yog ntsuas.

3.5 Lwm yam cuam tshuam

Lub viscosity ntawm aqueous tov ntawm hydroxypropyl methylcellulose kuj cuam tshuam los ntawm additives nyob rau hauv cov tshuaj, pH nqi ntawm cov tshuaj, thiab microbial degradation.Feem ntau, txhawm rau kom tau txais kev ua tau zoo dua viscosity lossis txo tus nqi ntawm kev siv, nws yog ib qho tsim nyog yuav tsum tau ntxiv rheology modifiers, xws li av nplaum, hloov kho av nplaum, polymer hmoov, hmoov txhuv nplej siab ether thiab aliphatic copolymer, rau cov tshuaj aqueous ntawm hydroxypropyl methylcellulose., thiab electrolytes xws li chloride, bromide, phosphate, nitrate, thiab lwm yam kuj tuaj yeem muab ntxiv rau hauv cov tshuaj aqueous.Cov additives no yuav tsis tsuas cuam tshuam cov viscosity ntawm cov kua aqueous, tab sis kuj cuam tshuam rau lwm cov khoom siv ntawm hydroxypropyl methylcellulose xws li dej tuav., sag resistance, thiab lwm yam.

Lub viscosity ntawm aqueous daws ntawm hydroxypropyl methylcellulose yuav luag tsis cuam tshuam los ntawm acid thiab alkali, thiab feem ntau ruaj khov nyob rau hauv thaj tsam ntawm 3 mus rau 11. Nws tuaj yeem tiv taus qee qhov tsis muaj zog acids, xws li formic acid, acetic acid, phosphoric acid. , boric acid, citric acid, thiab lwm yam. Txawm li cas los xij, concentrated acid yuav txo cov viscosity.Tab sis caustic soda, poov tshuaj hydroxide, dej txiv qaub, thiab lwm yam tsis muaj txiaj ntsig rau nws.Piv nrog rau lwm cov cellulose ethers, hydroxypropyl methylcellulose aqueous tov muaj cov tshuaj tiv thaiv kab mob zoo, lub ntsiab yog vim li cas hydroxypropyl methylcellulose muaj cov pab pawg hydrophobic nrog qib siab ntawm kev hloov pauv thiab steric hindrance ntawm pab pawg, Txawm li cas los xij, txij li qhov hloov pauv cov tshuaj tiv thaiv feem ntau tsis zoo li qub, lub unsubstituted anhydroglucose unit. yog yooj yim tshaj plaws eroded los ntawm cov kab mob, uas ua rau degradation ntawm cellulose ether molecules thiab saw scission.Qhov kev ua tau zoo yog tias qhov pom tseeb viscosity ntawm cov tshuaj aqueous txo qis.Yog tias tsim nyog los khaws cov tshuaj aqueous ntawm hydroxypropyl methylcellulose rau lub sijhawm ntev, nws raug nquahu kom ntxiv cov kab ntawm cov tshuaj tiv thaiv kab mob kom cov viscosity tsis hloov pauv ntau.Thaum xaiv cov tshuaj tiv thaiv kab mob, tshuaj tua kab mob lossis tshuaj tua kab mob, koj yuav tsum tau xyuam xim rau kev nyab xeeb, thiab xaiv cov khoom uas tsis muaj tshuaj lom rau tib neeg lub cev, muaj cov khoom ruaj khov thiab tsis muaj ntxhiab, xws li DOW Chem's AMICAL fungicides, CANGUARD64 preservatives, FUELSAVER cov kab mob. thiab lwm yam khoom.tuaj yeem ua lub luag haujlwm sib xws.


Post lub sij hawm: Oct-20-2022