Ua kom cov viscosity ntawm cellulose ethers feem ntau txo qhov ntws ntawm cov tshuaj. Cellulose ethers yog ib pab pawg ntawm cov dej-soluble polymers muab los ntawm cellulose uas feem ntau siv nyob rau hauv ntau yam kev lag luam, nrog rau cov kws kho mob, zaub mov, thiab kev tsim kho. Lub viscosity ntawm cov tshuaj yog ib qho kev ntsuas ntawm nws cov tsis kam mus ntws thiab cuam tshuam los ntawm tej yam xws li concentration, kub, thiab molecular hnyav ntawm cellulose ether.
Nov yog cov lus piav qhia ntxaws ntxiv ntawm yuav ua li cas nce cellulose ether viscosity cuam tshuam tus nqi ntws:
Kev sib raug zoo ntawm viscosity thiab flow rate:
Viscosity yog kev sib txhuam sab hauv hauv cov kua dej uas tawm tsam nws cov dej ntws. Nws yog ntsuas hauv units xws li centipoise (cP) lossis pascal vib nas this (Pa·s).
Tus nqi ntws ntawm cov tshuaj yog inversely proportional rau nws viscosity. Cov viscosity siab dua txhais tau tias muaj kev tiv thaiv ntau dua rau kev ntws, ua rau qis qis qis.
Cellulose ether muaj nuj nqi:
Cellulose ethers feem ntau ntxiv rau kev daws teeb meem los hloov nws cov khoom rheological. Cov hom muaj xws li methylcellulose (MC), hydroxypropylcellulose (HPC), thiab carboxymethylcellulose (CMC).
Lub viscosity ntawm cellulose ether daws nyob ntawm tej yam xws li concentration, kub thiab shear npaum li cas.
Concentration effect:
Ua kom cov concentration ntawm cellulose ethers feem ntau nce viscosity. Qhov no yog vim hais tias ib tug ntau dua concentration txhais tau hais tias ntau polymer chains nyob rau hauv cov kev daws, uas ua rau muaj zog txaus tsis kam.
Cov nyhuv kub:
Qhov kub thiab txias cuam tshuam rau viscosity ntawm cellulose ethers. Qee zaum, thaum kub nce, viscosity txo. Txawm li cas los xij, qhov kev sib raug zoo no yuav txawv nyob ntawm seb hom cellulose ether thiab nws cov khoom siv.
Shear rate dependence:
Lub viscosity ntawm cellulose ether daws feem ntau nyob ntawm tus nqi shear. Ntawm cov nqi shear ntau dua (piv txwv li, thaum siv los yog sib tov), viscosity yuav txo qis vim yog shear thinning tus cwj pwm.
Kev cuam tshuam rau tsheb:
Kev nce cellulose ether viscosity tuaj yeem ua rau txo qis hauv cov txheej txheem uas xav tau kev thauj mus los, kev siv, lossis kev daws teeb meem. Qhov no muaj feem xyuam rau daim ntawv thov xws li txheej, nplaum thiab tshuaj formulations.
Daim ntawv thov:
Txawm hais tias viscosities siab dua yuav tsum tau muaj nyob rau hauv qee qhov kev siv los txhim kho cov khoom lag luam lossis kev ruaj ntseg, qhov no yuav tsum sib npaug tiv thaiv cov tswv yim ntawm kev tuav thiab kev ua haujlwm.
Daim ntawv qhia optimization:
Formulators feem ntau optimize cellulose ether concentration thiab lwm yam formulation tsis mus cuag lub viscosity yuav tsum tau rau ib tug tshwj xeeb daim ntawv thov yam tsis cuam tshuam flowability mus rau ib tug tsis txaus degree.
Kev nce cellulose ether viscosity feem ntau ua rau txo qis ntawm cov dej ntws vim muaj zog txaus. Txawm li cas los xij, kev sib raug zoo raug cuam tshuam los ntawm cov yam ntxwv xws li concentration, kub thiab shear tus nqi, thiab cov kev hloov kho tuaj yeem ua kom ua tiav qhov xav tau qhov sib npaug ntawm viscosity thiab flowability.
Post lub sij hawm: Jan-20-2024