qhia
Cellulose ethers yog anionic dej-soluble polymers muab los ntawm cellulose. Cov polymers no muaj ntau daim ntawv thov hauv ntau yam lag luam xws li zaub mov, tshuaj, tshuaj pleev ib ce, thiab kev tsim kho vim lawv cov khoom xws li thickening, gelling, film-forming, thiab emulsifying. Ib qho ntawm cov khoom tseem ceeb tshaj plaws ntawm cellulose ethers yog lawv cov thermal gelation kub (Tg), qhov kub thiab txias ntawm cov polymer mus rau theem hloov ntawm sol mus rau gel. Cov cuab yeej no yog qhov tseem ceeb hauv kev txiav txim siab kev ua haujlwm ntawm cellulose ethers hauv ntau daim ntawv thov. Hauv tsab xov xwm no, peb tham txog cov thermal gelation kub ntawm hydroxypropyl methylcellulose (HPMC), yog ib qho ntawm feem ntau siv cellulose ethers hauv kev lag luam.
Thermal gelation kub ntawm HPMC
HPMC yog ib tug semi-synthetic cellulose ether dav siv nyob rau hauv ntau yam kev siv vim nws cov yam ntxwv tshwj xeeb. HPMC yog soluble nyob rau hauv dej, tsim kom meej viscous daws ntawm tsawg concentrations. Ntawm qhov siab dua, HPMC tsim cov gels uas thim rov qab thaum cua sov thiab txias. Thermal gelation ntawm HPMC yog txheej txheem ob-kauj ruam uas muaj kev tsim cov micelles ua raws li kev sib sau ntawm micelles los tsim ib lub gel network (Daim duab 1).
Lub thermal gelation kub ntawm HPMC nyob ntawm ntau yam xws li kev hloov pauv (DS), qhov hnyav molecular, concentration, thiab pH ntawm cov tshuaj. Feem ntau, qhov siab dua ntawm DS thiab molecular hnyav ntawm HPMC, qhov siab dua qhov thermal gelation kub. Qhov concentration ntawm HPMC hauv kev daws kuj cuam tshuam Tg, qhov siab dua qhov concentration, qhov siab dua Tg. Cov pH ntawm cov tshuaj kuj tseem cuam tshuam rau Tg, nrog rau cov kua qaub uas ua rau Tg qis dua.
Thermal gelation ntawm HPMC yog thim rov qab thiab tuaj yeem cuam tshuam los ntawm ntau yam sab nraud xws li shear force, kub, thiab ntsev concentration. Shear rhuav tshem cov qauv gel thiab txo Tg, thaum nce kub ua rau cov gel yaj thiab txo Tg. Ntxiv ntsev rau cov tshuaj kuj tseem cuam tshuam Tg, thiab muaj cov cations xws li calcium thiab magnesium tsub kom Tg.
Daim ntawv thov sib txawv Tg HPMC
Tus cwj pwm thermogelling ntawm HPMC tuaj yeem tsim kho rau ntau daim ntawv thov. Tsawg Tg HPMCs yog siv rau hauv daim ntawv thov uas yuav tsum tau ceev gelation, xws li instant khoom qab zib, ntses thiab kua zaub formulations. HPMC nrog Tg siab yog siv rau hauv daim ntawv thov uas yuav tsum tau ncua sij hawm lossis ncua sij hawm gelation, xws li kev tsim cov tshuab xa tshuaj, cov ntsiav tshuaj tso tawm, thiab kev hnav khaub ncaws.
Hauv kev lag luam khoom noj khoom haus, HPMC yog siv los ua cov thickener, stabilizer thiab gelling tus neeg sawv cev. Tsawg Tg HPMC yog siv rau hauv cov khoom qab zib instant formulations uas yuav tsum tau ceev gelation los muab qhov xav tau kev ntxhib los mos thiab qhov ncauj. HPMC nrog Tg siab yog siv nyob rau hauv cov roj tsawg kis formulations uas ncua los yog ntev gelation yog xav tau los tiv thaiv syneresis thiab tswj kev sib kis qauv.
Hauv kev lag luam kws tshuaj, HPMC yog siv los ua ib qho kev sib khi, disintegrant thiab ruaj khov tso tawm tus neeg sawv cev. HPMC nrog Tg siab yog siv rau hauv kev tsim cov tshuaj txuas ntxiv-tso tawm, qhov twg ncua sij hawm lossis ntev gelation yuav tsum tso cov tshuaj nyob rau lub sijhawm ntev. Tsawg Tg HPMC yog siv rau hauv kev tsim cov ntsiav tshuaj ntawm qhov ncauj disintegrating, qhov twg sai sai disintegration thiab gelation yuav tsum tau muab lub qhov ncauj xav tau thiab yooj yim ntawm nqos.
nyob rau hauv xaus
Lub thermal gelation kub ntawm HPMC yog cov cuab yeej tseem ceeb uas txiav txim siab nws tus cwj pwm hauv ntau daim ntawv thov. HPMC tuaj yeem kho nws Tg los ntawm qib kev hloov pauv, qhov hnyav molecular, concentration thiab pH tus nqi ntawm cov tshuaj kom haum rau cov kev siv sib txawv. HPMC nrog Tg qis yog siv rau cov ntawv thov uas xav tau gelation ceev, thaum HPMC nrog Tg siab yog siv rau cov ntawv thov uas yuav tsum tau ncua sijhawm lossis ntev gelation. HPMC yog ntau yam thiab ntau yam cellulose ether nrog ntau yam kev siv hauv ntau yam lag luam.
Post lub sij hawm: Aug-24-2023