Hydroxypropyl methylcellulose (HPMC)yog ib qho non-ionic, dej-soluble cellulose sib xyaw ether. Qhov tsos yog dawb rau me ntsis daj hmoov lossis cov khoom siv granular, tsis muaj saj, tsis muaj ntxhiab, tsis muaj tshuaj lom, ruaj khov tshuaj lom neeg, thiab yaj hauv dej los ua ib qho du, pob tshab thiab viscous kua. Ib qho ntawm cov khoom tseem ceeb tshaj plaws ntawm hydroxypropyl methylcellulose hauv daim ntawv thov yog tias nws ua rau kom cov kua viscosity. Cov nyhuv thickening nyob ntawm qib ntawm polymerization (DP) ntawm cov khoom, qhov concentration ntawm cellulose ether hauv cov kua dej, qhov shear rate, thiab qhov kub ntawm cov kua. Thiab lwm yam.
01
Hom kua ntawm HPMC aqueous kua
Feem ntau, qhov kev ntxhov siab ntawm cov kua dej hauv kev ntws shear tuaj yeem qhia ua haujlwm ntawm tsuas yog qhov nrawm shear ƒ (γ), tsuav yog nws tsis nyob ntawm lub sijhawm. Nyob ntawm daim ntawv ntawm ƒ (γ), cov kua dej tuaj yeem faib ua ntau hom, uas yog: Newtonian kua dej, dilatant kua dej, pseudoplastic kua dej thiab Bingham yas kua dej.
Cov cellulose ethers raug muab faib ua ob pawg: ib qho yog non-ionic cellulose ether thiab lwm qhov yog ionic cellulose ether. Rau qhov rheology ntawm ob hom cellulose ethers no. SC Naik et al. tau ua ib qho kev tshawb fawb sib piv thiab kev sib txuas lus ntawm hydroxyethyl cellulose thiab sodium carboxymethyl cellulose cov kua. Cov txiaj ntsig tau qhia tias ob qho tib si non-ionic cellulose ether cov kua thiab ionic cellulose ether cov kua yog pseudoplastic. Cov dej ntws, piv txwv li cov dej ntws tsis-Newtonian, mus rau Newtonian kua tsuas yog ntawm qhov tsawg heev concentration. Lub pseudoplasticity ntawm hydroxypropyl methylcellulose kua ua lub luag haujlwm tseem ceeb hauv daim ntawv thov. Piv txwv li, thaum siv rau hauv cov txheej, vim yog cov yam ntxwv shear thinning ntawm cov kua dej, qhov viscosity ntawm cov kua txo qis nrog qhov nce ntawm shear tus nqi, uas yog conducive rau qhov sib xws ntawm cov xim pigment, thiab kuj ua rau kom cov kua ntawm cov txheej. Cov nyhuv yog loj heev; thaum so, qhov viscosity ntawm cov kua yog qhov loj heev, uas zoo tiv thaiv kev tso cov xim pigment hauv cov txheej.
02
Txoj Kev Ntsuas Viscosity HPMC
Ib qho cim qhia tseem ceeb los ntsuas qhov ua kom tuab ntawm hydroxypropyl methylcellulose yog qhov pom tseeb viscosity ntawm cov kua dej. Cov txheej txheem ntsuas ntawm qhov pom tseeb viscosity feem ntau suav nrog capillary viscosity txoj kev, rotational viscosity txoj kev thiab poob pob viscosity txoj kev.
qhov twg: yog qhov pom tseeb viscosity, mPa s; K yog viscometer tas mus li; d yog qhov ceev ntawm cov qauv kua ntawm 20/20 ° C; t yog lub sijhawm rau cov kua hla dhau qhov sab saud ntawm viscometer mus rau qhov cim qis tshaj, s; Lub sijhawm uas cov roj txheem ntws los ntawm viscometer raug ntsuas.
Txawm li cas los xij, txoj kev ntsuas los ntawm capillary viscometer yog qhov teeb meem ntau dua. Cov viscosities ntawm ntaucov cellulose ethersnyuaj rau kev soj ntsuam siv lub capillary viscometer vim tias cov tshuaj no muaj cov khoom me me uas tsis yaj uas tsuas yog pom thaum lub capillary viscometer raug thaiv. Yog li ntawd, feem ntau cov chaw tsim khoom siv cov rotational viscometers los tswj qhov zoo ntawm hydroxypropyl methylcellulose. Brookfield viscometers feem ntau siv hauv cov tebchaws txawv teb chaws, thiab NDJ viscometers siv hauv Suav teb.
03
Cov yam cuam tshuam rau HPMC viscosity
3.1 Kev sib raug zoo nrog qib kev sib sau ua ke
Thaum lwm cov kev ntsuas tseem tsis tau hloov pauv, qhov viscosity ntawm hydroxypropyl methylcellulose kua yog proportional rau qib ntawm polymerization (DP) lossis molecular hnyav lossis molecular saw ntev, thiab nce nrog qhov nce ntawm qib ntawm polymerization. Cov nyhuv no yog qhov pom tseeb dua hauv cov ntaub ntawv ntawm qib qis ntawm polymerization dua li hauv cov ntaub ntawv ntawm qib siab ntawm polymerization.
3.2 Kev sib raug zoo ntawm viscosity thiab concentration
Qhov viscosity ntawm hydroxypropyl methylcellulose nce nrog rau qhov nce ntawm qhov concentration ntawm cov khoom hauv cov kua dej. Txawm tias qhov kev hloov pauv me me ntawm qhov concentration yuav ua rau muaj kev hloov pauv loj hauv viscosity. Nrog rau qhov nominal viscosity ntawm hydroxypropyl methylcellulose Cov nyhuv ntawm qhov kev hloov pauv ntawm qhov concentration ntawm cov kua rau qhov viscosity ntawm cov kua yog qhov pom tseeb ntau dua.
3.3 Kev sib raug zoo ntawm viscosity thiab shear rate
Hydroxypropyl methylcellulose aqueous solution muaj cov yam ntxwv ntawm shear thinning. Hydroxypropyl methylcellulose ntawm cov nominal viscosity sib txawv yog npaj rau hauv 2% aqueous kua, thiab nws cov viscosity ntawm cov shear rates sib txawv yog ntsuas feem. Cov txiaj ntsig yog raws li nram no Raws li qhia hauv daim duab. Ntawm qhov shear rate qis, qhov viscosity ntawm hydroxypropyl methylcellulose kua tsis hloov pauv ntau. Nrog rau kev nce ntawm shear rate, qhov viscosity ntawm hydroxypropyl methylcellulose kua nrog nominal viscosity siab dua txo qis dua, thaum cov kua nrog viscosity qis tsis txo qis.
3.4 Kev sib raug zoo ntawm viscosity thiab kub
Qhov viscosity ntawm cov kua hydroxypropyl methylcellulose raug cuam tshuam loj heev los ntawm qhov kub thiab txias. Thaum qhov kub nce ntxiv, qhov viscosity ntawm cov kua txo qis. Raws li pom hauv daim duab, nws tau npaj rau hauv cov kua dej nrog qhov concentration ntawm 2%, thiab qhov kev hloov pauv ntawm viscosity nrog qhov nce ntawm qhov kub thiab txias raug ntsuas.
3.5 Lwm yam uas cuam tshuam rau
Qhov viscosity ntawm cov kua dej ntawm hydroxypropyl methylcellulose kuj raug cuam tshuam los ntawm cov additives hauv cov kua, pH tus nqi ntawm cov kua, 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 qhov tsim nyog los ntxiv rheology modifiers, xws li av nplaum, hloov kho av nplaum, polymer hmoov, hmoov txhuv nplej siab ether thiab aliphatic copolymer, rau hauv cov kua dej ntawm hydroxypropyl methylcellulose. , thiab electrolytes xws li chloride, bromide, phosphate, nitrate, thiab lwm yam kuj tuaj yeem ntxiv rau hauv cov kua dej. Cov additives no yuav tsis tsuas yog cuam tshuam rau cov khoom viscosity ntawm cov kua dej, tab sis kuj cuam tshuam rau lwm yam khoom siv ntawm hydroxypropyl methylcellulose xws li dej khaws cia. , sag tsis kam, thiab lwm yam.
Qhov viscosity ntawm cov kua dej ntawm hydroxypropyl methylcellulose yuav luag tsis cuam tshuam los ntawm cov kua qaub thiab alkali, thiab feem ntau ruaj khov nyob rau hauv qhov ntau ntawm 3 txog 11. Nws tuaj yeem tiv taus qee qhov ntawm cov kua qaub tsis muaj zog, xws li formic acid, acetic acid, phosphoric acid, boric acid, citric acid, thiab lwm yam. Txawm li cas los xij, cov kua qaub concentrated yuav txo qhov viscosity. Tab sis caustic soda, potassium hydroxide, lime water, thiab lwm yam muaj me ntsis cuam tshuam rau nws. Piv nrog rau lwm cov cellulose ethers,hydroxypropyl methylcelluloseCov kua dej muaj kev ruaj khov zoo antimicrobial, qhov laj thawj tseem ceeb yog tias hydroxypropyl methylcellulose muaj cov pab pawg hydrophobic nrog qib siab ntawm kev hloov pauv thiab steric hindrance ntawm cov pab pawg Txawm li cas los xij, txij li thaum qhov kev hloov pauv feem ntau tsis sib xws, lub unit unsubstituted anhydroglucose yooj yim tshaj plaws los ntawm cov kab mob me me, ua rau muaj kev puas tsuaj ntawm cellulose ether molecules thiab saw hlau scission. Qhov kev ua tau zoo yog tias qhov pom tseeb viscosity ntawm cov kua dej txo qis. Yog tias nws tsim nyog khaws cov kua dej ntawm hydroxypropyl methylcellulose rau lub sijhawm ntev, nws raug pom zoo kom ntxiv ib qho me me ntawm cov neeg sawv cev antifungal kom qhov viscosity tsis hloov pauv ntau. Thaum xaiv cov neeg sawv cev tiv thaiv fungal, preservatives lossis fungicides, koj yuav tsum tau them sai sai 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 bacteria agents thiab lwm yam khoom. tuaj yeem ua lub luag haujlwm sib xws.
Lub sijhawm tshaj tawm: Plaub Hlis-28-2024