HydroxyPropyyl methylulose (HPMC) yog lub cellulose dav siv nyob rau hauv cov teb ntawm cov ntaub ntawv hauv tsev, cov chaw muag tshuaj, zaub mov thiab tshuaj pleev ib ce. Lub viscos ntawm HPMC yog ib qho ntawm nws cov txuj ci tseem ceeb vim cuam tshuam rau lub fluidity, txheej khoom thiab lwm yam ntxwv ntawm cov khoom. Yog li, nkag siab qhov cuam tshuam rau cov visccosity ntawm HPMC yog qhov tseem ceeb rau nws daim ntawv thov thiab cov khoom tsim hauv ntau thaj teb.
1. Cov nyhuv ntawm molecular hnyav
Lub cev hnyav molecular ntawm HPMC muaj qhov cuam tshuam tseem ceeb rau lub viscosity. Qhov loj dua cov molecular hnyav, ntau dua viscosity ntawm kev daws. Qhov no yog vim HPMC nrog lub cev loj molecular hnyav cov qauv molecular saw hauv kev daws teeb meem thiab ua rau muaj kev nce qib hauv viscosposity. Nyob rau tib lub sijhawm, qhov hnyav loj molecular yuav ua rau muaj kev hloov pauv rheological muaj kev tswj hwm, uas yog ib qho tseem ceeb rau kev ua tau zoo ntawm cov txheej txheem, cov nplaum thiab lwm yam kev siv. Ob txoj kev sim thiab theoretical kev tshawb fawb tau qhia tias qhov hnyav viscosity thiab molecular qhov hnyav ntawm HPMC thav duab tsis nce linarly raws li cov phaus molecular nce.
2. Hwj Chim ntawm cov qib ntawm kev hloov pauv
Cov qib degree hloov chaw ntawm hydroxypropyl (-ch3chohch2-) thiab methyl (-ch3) pawg hauv HPMC yog qhov tseem ceeb cuam tshuam rau nws solubility thiab viscosity. Cov degree ntawm kev hloov pauv yog hais txog kev faib ua feem ntawm hydroxyl pawg (-h) ntawm HOLMC molecypropyl thiab methyl pawg. Thaum cov degree ntawm cov pab pawg hydroxypropyl nce ntxiv, thiab cov molecular txuas ntxiv, thiab cov tshuaj molecular yuav muaj zog, thiab cov tshuaj molecular yuav muaj zog, thiab kev nce qib ntawm kev daws teeb meem; Thaum nce cov methyl pab pawg yuav zoo li nce hydrophobicity ntawm kev daws teeb meem, ua rau solubility txo qis, yog li cuam tshuam viscosity. Feem ntau, HPMC nrog cov qib siab hloov chaw muaj siab solubility thiab viscosity, thiab tuaj yeem ntsib viscosity xav tau ntawm ntau daim teb.
3. Cov nyhuv ntawm kev daws teeb meem
Lub viscosity ntawm HPMC kev daws teeb meem yog ze rau nws txoj kev xav. Raws li cov concentration ntawm cov kev daws teeb meem, kev sib cuam tshuam ntawm cov lwg me me nce siab, ua rau muaj kev tawm tsam kom nce siab. Ntawm cov qis dua, hpmc molecules muaj nyob rau hauv daim ntawv ntawm ib txoj saw hlau, thiab viscosity hloov tau yooj yim heev. Thaum lub siab xav ncav cuag ib qho tseem ceeb tus nqi, HPMC lwg me me yuav ua rau lwm tus, sib sau ua ke, ua rau viscosity kom nce sai. Ib qho ntxiv, qhov nce hauv kev daws teeb meem yuav ua rau HPMC los ua kom muaj kev cuam tshuam shear thickening,, tus viscosity yuav nce ntxiv rau hauv qhov kev txiav txim ntawm kev quab yuam loj.
4. Dab tsi ntawm cov kuab tshuaj hom
Hom tshuaj tiv thaiv kuj tseem muaj qhov cuam tshuam tseem ceeb rau cov solubility thiab viscosity ntawm HPMC. HPMC tuaj yeem yaj nyob hauv dej thiab qee cov kuab tshuaj organic (xws li Methanol, acetone), tab sis txawv cov kuab tshuaj muaj txawv solubility thiab dispersibility. Hauv dej, HPMC feem ntau muaj nyob rau hauv daim ntawv viscosity viscosity, thaum nyob rau hauv cov kuab tshuaj yeeb yaj kiab nws cov khoom pov thawj qis viscosity. Lub polarity ntawm cov kuab tshuaj muaj ntau dua kev cuam tshuam rau kev viscosity ntawm HPMC. Cov kuab tshuaj nrog cov dej polarity siab dua (xws li dej) yuav txhim kho cov hydration ntawm hpmc lwg me me, yog li nce lub viscosity ntawm kev daws. Tsis-polar cov kuab tshuaj tsis tuaj yeem yaj HPMC, ua rau kev daws teeb meem rau kev nthuav tawm viscosity lossis tsis tiav kev txiav txim siab. Ib qho ntxiv, xaiv thiab piv ntawm cov kuab tshuaj sib xyaw kuj tseem yuav cuam tshuam rau qhov kev ua tau zoo ntawm HPMC.
5. Cov nyhuv ntawm kub
Qhov kub yog ib qho ntawm ib puag ncig ib puag ncig cuam tshuam rau cov viscosity ntawm HPMC. Feem ntau, cov viscosity ntawm HPMC txo raws li qhov kub nce ntxiv. Qhov no yog vim qhov kub siab yuav rhuav tshem cov hydrogen bonds thiab lwm yam kev sib cuam tshuam ntawm HPMC molecular swb yooj yim, yog li txo lub viscosity ntawm kev daws. Ntawm qee qhov kub siab, HPMC kuj tseem tuaj yeem dhau los ua cov gelation los ua cov qauv gel ruaj khov. Qhov no thermal gelling cuab yeej tau siv dav hauv cov ntaub ntawv hauv tsev thiab kev lag luam khoom noj raws li nws muab kev txhawb nqa viscosity thiab cov qauv kev txhawb nqa. Tsis tas li ntawd, kub muaj cov teebmeem sib txawv ntawm kev visccosity ntawm hpmcos nrog hnyav thiab hnyav hloov chaw. Feem ntau, HPMCS nrog hnyav molecular hnyav thiab qib siab ntawm kev hloov pauv tau ntau dua qhov hloov kom sov.
6. Cov nyhuv ntawm tus nqi
Txawm hais tias HPMC yog ib qho nruab nrab polymer thiab feem ntau tsis txaus siab rau PH / nws tuaj yeem cuam tshuam nyob rau hauv cov teeb meem acid los yog alkaline ib puag ncig). Qhov no yog vim hais tias ib puag ncig acid los yog alkali ib puag ncig yuav rhuav tshem cov qauv molecular ntawm HPMC thiab txo qis nws qhov ruaj khov, ua rau muaj kev txo qis. Rau qee cov ntawv thov, xws li kev npaj khoom lag luam thiab khoom noj ntxiv, PT kev tswj hwm yog qhov tshwj xeeb yog qhov tshwj xeeb yog HPMC viscosity tseem ruaj khov nyob rau hauv cov ntau yam tsim nyog.
7. Cov nyhuv ntawm ionic lub zog
Lub khoos kas ionic hauv kev daws teeb meem tseem cuam tshuam rau kev coj tus cwj pwm viscos ntawm HPMC. Ib puag ncig zoo ionic yuav pov hwm cov nqi ntawm HPMC molecular rins, ua rau nws yooj yim rau cov kev ua tiav, yog li txo lub viscosity. Feem ntau, thaum npaj HPMC aqueous kev daws teeb meem, lub ion siab yuav tsum tau tswj hwm viscosity thiab qhov tshwj xeeb tshaj plaws hauv cov tshuaj thiab chaw pleev tshuaj kom zoo nkauj.
Lub visccosity ntawm HPMC cuam tshuam los ntawm ntau yam, suav nrog txoj kev hnyav, qib siab, kev daws hom, ntsuas kub thiab ionic lub zog. Molecular hnyav thiab qib kawm hloov pauv feem ntau txiav txim siab rau kev siv viscosity xws li kev daws teeb meem thiab qhov kub thiab txias rau nws. Hauv kev siv cov tswv yim, tsim nyog HPMC uas tsim nyog rau cov neeg mob yuav tsum tau xaiv raws li cov kev xav tau tshwj xeeb kom ua tiav qhov kev ua tau zoo tshaj plaws. Qhov kev sib cuam tshuam ntawm cov yam ntxwv kev ua tau zoo thiab siv cov chaw ua haujlwm ntawm HPMC, muab kev txhawb nqa theoretical rau nws cov ntaub ntawv dav, kws tshuaj, zaub mov thiab lwm yam kev lag luam.
Lub sijhawm Post: Feb-15-2025