HPMC lossis hydroxypropyl methylcellulose yog ib yam khoom siv tau ntau yam hauv ntau yam lag luam suav nrog tshuaj, tshuaj pleev ib ce thiab khoom noj. Nws yog siv dav ua cov khoom ua kom tuab thiab emulsifier, thiab nws cov viscosity hloov pauv nyob ntawm qhov kub uas nws raug. Hauv tsab xov xwm no, peb yuav tsom mus rau kev sib raug zoo ntawm viscosity thiab kub hauv HPMC.
Viscosity yog txhais tias yog qhov ntsuas ntawm cov kua dej tsis kam rau ntws. HPMC yog ib yam khoom semi-khoom uas nws qhov kev ntsuas tsis kam nyob ntawm ntau yam, suav nrog qhov kub. Txhawm rau kom nkag siab txog kev sib raug zoo ntawm viscosity thiab kub hauv HPMC, peb yuav tsum paub ua ntej tias cov tshuaj no tsim li cas thiab nws yog dab tsi.
HPMC yog los ntawm cellulose, ib qho polymer uas muaj nyob hauv cov nroj tsuag. Yuav kom tsim tau HPMC, cellulose yuav tsum tau hloov kho nrog propylene oxide thiab methyl chloride. Qhov kev hloov kho no ua rau muaj hydroxypropyl thiab methyl ether pawg hauv cov saw cellulose. Qhov tshwm sim yog ib qho khoom semi-solid uas tuaj yeem yaj hauv dej thiab cov kuab tshuaj organic thiab siv rau ntau yam kev siv, suav nrog ua ib txheej rau cov ntsiav tshuaj thiab ua ib qho thickening rau cov khoom noj, thiab lwm yam.
Qhov viscosity ntawm HPMC nyob ntawm qhov concentration ntawm cov tshuaj thiab qhov kub uas nws raug. Feem ntau, qhov viscosity ntawm HPMC txo qis nrog rau qhov concentration nce ntxiv. Qhov no txhais tau tias qhov concentration siab dua ntawm HPMC ua rau muaj viscosities qis dua thiab rov qab los.
Txawm li cas los xij, qhov kev sib raug zoo ntawm viscosity thiab kub yog qhov nyuaj dua. Raws li tau hais ua ntej, viscosity ntawm HPMC nce nrog qhov kub txo qis. Qhov no txhais tau tias thaum HPMC raug rau qhov kub qis, nws lub peev xwm ntws txo qis thiab nws dhau los ua viscous dua. Ib yam li ntawd, thaum HPMC raug rau qhov kub siab, nws lub peev xwm ntws nce thiab nws viscosity txo qis.
Muaj ntau yam uas cuam tshuam rau kev sib raug zoo ntawm qhov kub thiab viscosity hauv HPMC. Piv txwv li, lwm cov solutes uas muaj nyob rau hauv cov kua tuaj yeem cuam tshuam rau viscosity, ib yam li pH ntawm cov kua. Feem ntau, txawm li cas los xij, muaj kev sib raug zoo rov qab ntawm viscosity thiab kub hauv HPMC vim yog qhov cuam tshuam ntawm qhov kub thiab txias rau hydrogen bonding thiab molecular interactions ntawm cellulose saw hauv HPMC.
Thaum HPMC raug rau qhov kub qis, cov saw hlau cellulose yuav tawv dua, uas ua rau muaj kev sib txuas hydrogen ntau ntxiv. Cov hydrogen bonds no ua rau cov tshuaj tsis kam ntws, yog li ua rau nws cov viscosity nce ntxiv. Ntawm qhov tod tes, thaum HPMCs raug rau qhov kub siab, cov saw hlau cellulose yuav yoog tau ntau dua, uas ua rau muaj cov hydrogen bonds tsawg dua. Qhov no txo cov tshuaj tsis kam ntws, ua rau viscosity qis dua.
Nws yog ib qho tsim nyog sau tseg tias thaum feem ntau muaj kev sib raug zoo rov qab ntawm viscosity thiab kub ntawm HPMC, qhov no tsis yog ib txwm muaj rau txhua hom HPMC. Qhov kev sib raug zoo tseeb ntawm viscosity thiab kub yuav txawv nyob ntawm cov txheej txheem tsim khoom thiab qib tshwj xeeb ntawm HPMC siv.
HPMC yog ib yam khoom siv ntau yam uas siv dav hauv ntau yam lag luam rau nws cov khoom ua kom tuab thiab emulsifying. Qhov viscosity ntawm HPMC nyob ntawm ntau yam, suav nrog qhov concentration ntawm cov khoom thiab qhov kub uas nws raug. Feem ntau, qhov viscosity ntawm HPMC yog inversely proportional rau qhov kub, uas txhais tau tias thaum qhov kub txo qis, qhov viscosity nce. Qhov no yog vim qhov cuam tshuam ntawm qhov kub ntawm hydrogen bonding thiab molecular interactions ntawm cellulose saw hauv HPMC.
Lub sijhawm tshaj tawm: Cuaj hlis-08-2023