qhia
Hydroxypropyl methylcellulose (HPMC) yog ib qho nonionic cellulose ether uas tau siv dav hauv ntau lub lag luam vim nws cov khoom zoo heev xws li dej solubility, zaj duab xis-tsim khoom, thiab adhesion.Nws lub peev xwm los hloov viscosity ua rau nws zoo tagnrho rau ntau daim ntawv thov, suav nrog zaub mov, tshuaj thiab xim.HPMC yog muab los ntawm natural polymer cellulose, uas yog glycosylated los tsim ib tug cellulose-oxygen network qauv.Cov khoom thiab viscosity ntawm HPMC nyob ntawm seb cov yam ntxwv xws li qhov hnyav molecular, qib kev hloov pauv, concentration, hnyav hom, pH, kub thiab ionic zog.
Hauv tsab xov xwm no, peb yuav tham txog yam uas cuam tshuam rau HPMC viscosity thiab lawv cov txheej txheem.
molecular hnyav
Qhov hnyav molecular ntawm HPMC feem ntau txiav txim siab nws cov viscosity.Obviously, qhov siab dua qhov hnyav molecular, qhov viscous ntau dua.Qhov hnyav molecular ntawm HPMC yog li ntawm 10^3 txog 10^6 Da.Raws li qhov hnyav molecular nce, tus naj npawb ntawm entanglements ntawm HPMC chains kuj nce, uas ua rau muaj kev nce hauv viscosity.
Degree ntawm kev hloov
Qhov degree ntawm kev hloov pauv (DS) ntawm HPMC txiav txim siab txog cov pawg hydroxypropyl thiab methyl hauv nws cov qauv.HPMC nrog DS siab dua yog ntau hydrophobic thiab dej-soluble tsawg dua HPMC nrog qis dua DS.Qib ntawm kev hloov pauv cuam tshuam rau kev solubility ntawm HPMC hauv dej, uas cuam tshuam rau nws lub peev xwm los tsim cov tes hauj lwm sib txuas thiab nce viscosity.
tsom
Concentration yog ib qho tseem ceeb tshaj plaws uas cuam tshuam rau HPMC viscosity.Feem ntau, cov viscosity ntawm HPMC cov kev daws teeb meem nce nrog nce concentration.Tus cwj pwm no raug ntaus nqi los ntawm kev cuam tshuam ntawm HPMC chains ntawm ntau dua.
Hom kuab tshuaj
Hom hnyav ua lub luag haujlwm tseem ceeb hauv viscosity ntawm HPMC.Qee zaum, HPMC muaj viscosity ntau dua hauv dej dua li hauv qee cov kuab tshuaj organic.Qhov laj thawj yuav yog vim muaj kev cuam tshuam sib txawv ntawm cov kuab tshuaj thiab HPMC molecules.
pH
Cov pH ntawm cov tshuaj tuaj yeem cuam tshuam qhov viscosity ntawm HPMC.Ntawm acidic pH, HPMC tuaj yeem tsim cov ntawv cog lus hydrogen nrog cov kuab tshuaj, ua rau muaj kev nce ntxiv hauv viscosity.Tsis tas li ntawd, pH cuam tshuam rau qib ntawm ionization ntawm hydroxypropyl thiab methyl pawg, uas cuam tshuam rau electrostatic thiab hydrophobic kev sib cuam tshuam ntawm HPMC chains.
kub
Kub kuj muaj qhov cuam tshuam rau viscosity ntawm HPMC.Ntawm qhov kub siab dua, HPMC cov molecules muaj kev txav mus los ntau dua, ua rau txo qis kev sib cuam tshuam hauv nruab nrab.Qhov kev coj cwj pwm no feem ntau ua rau txo qis hauv cov tshuaj viscosity.Qhov xwm txheej sib txawv yog pom ntawm qhov kub thiab txias.Vim lub rigidity ntawm HPMC molecules, lub viscosity ntawm cov tshuaj nce nrog txo kub.
ionic zog
Ionic lub zog yog lwm yam uas cuam tshuam rau HPMC viscosity.Qhov kev ntsuas no hais txog qhov concentration ntawm ions hauv cov tshuaj.Cov ntsev xws li sodium chloride tuaj yeem cuam tshuam qhov viscosity ntawm HPMC los ntawm kev ua kom muaj kev hloov pauv hauv lub xeev ionization ntawm hydroxypropyl thiab methyl pawg.Qhov kev hloov pauv no hloov pauv kev sib cuam tshuam ntawm HPMC cov molecules, yog li cuam tshuam rau viscosity ntawm cov tshuaj.
nyob rau hauv xaus
Lub viscosity ntawm HPMC cuam tshuam los ntawm ntau yam, nrog rau qhov hnyav molecular, qib ntawm kev hloov pauv, concentration, hnyav hom, pH, kub thiab ionic zog.Thaum tsim cov khoom uas muaj HPMC, nws yog ib qho tseem ceeb uas yuav tau xav txog tag nrho cov yam ntxwv no kom ntseeg tau tias qhov xav tau viscosity tiav.Kev txhim kho kom zoo ntawm cov xwm txheej no tuaj yeem ua rau kev tsim cov khoom lag luam zoo thiab ruaj khov uas ua tau raws li nws lub hom phiaj.
Post lub sij hawm: Sep-12-2023