Hauv kev lag luam niaj hnub no, txhawm rau txhim kho cov khoom rheological, kev ruaj khov cia thiab kev ua haujlwm ntawm cov txheej, nws feem ntau tsim nyog ntxiv qee cov khoom siv polymer ua haujlwm. Ntawm lawv,Hydroxyethyl Cellulose (HEC)thiabHydroxypropyl methylcellulose (HPMC)yog ob qho cellulose ether thickeners thiab stabilizers uas siv dav. Txawm hais tias lawv ob leeg yog non-ionic cellulose ethers, muaj qhov sib txawv pom tseeb hauv cov qauv tshuaj lom neeg, cov yam ntxwv kev ua tau zoo thiab cov teebmeem ntawm kev siv hauv cov txheej txheem.
1. Cov qauv tshuaj lom neeg thiab kev yaj
HEC yog cov polymer uas yaj tau hauv dej uas tsis yog ionic ua los ntawm cov cellulose ntuj los ntawm kev qhia cov pab pawg hydroxyethyl los ntawm kev sib xyaw ua ke. Nws cov qauv molecular nplua nuj nyob rau hauv cov hydrophilic hydroxyl thiab hydroxyethyl pawg, uas ua rau nws muaj cov dej solubility zoo. HEC tuaj yeem yaj sai sai hauv dej txias los ua cov kua nplaum pob tshab.
HPMC yog ib qho polymer tsim los ntawm kev qhia txog hydroxypropyl thiab methyl substituents rau ntawm cov cellulose molecules. Vim muaj nws cov hydrophobic methyl pawg, nws muaj kev ua haujlwm zoo dua ntawm qhov chaw thiab cov khoom tsim zaj duab xis dua li HEC. HPMC swells qeeb hauv dej txias, siv sijhawm me ntsis kom yaj tag, thiab cuam tshuam loj heev los ntawm qhov kub thiab txias.
2. Kev sib piv ntawm cov khoom rheological
HEC muaj tus cwj pwm rheological linear, qhia pseudoplasticity, uas yog, shear-thinning yam ntxwv, thiab yog tsim rau cov txheej txheem txheej uas xav tau kev sib npaug zoo. Lub viscosity ntawm HEC kua txo qis hauv qab kev sib npaug siab, uas pab nrog txhuam, txheej txheej roller thiab kev sib npaug thaum lub sijhawm tsim kho.
Cov tshuaj HPMC qhia tau tias muaj tus cwj pwm pseudoplastic muaj zog dua, nrog rau viscosity siab dua nyob rau hauv qis shear, uas pab tiv thaiv kev sedimentation thiab sagging; qhov viscosity txo qis ntau nyob rau hauv high shear, uas yog qhov zoo rau kev txhim kho kev tsim kho. Yog li ntawd, HPMC ua tau zoo dua hauv cov ntawv thov txheej facade uas xav tau cov khoom tiv thaiv sagging muaj zog.
3. Kev khaws dej thiab kev ua haujlwm ntawm kev tsim kho
HPMC muaj kev khaws cia dej zoo dua li HEC, tshwj xeeb tshaj yog nyob rau hauv qhov chaw qhuav lossis qhov kub thiab txias, HPMC tuaj yeem ncua qhov dej evaporation thiab tiv thaiv kev tawg lossis ntsws ntawm cov zaj duab xis txheej. Qhov no ua rau HPMC kuj siv dav hauv putty, gypsum thiab cement-based coatings, tshwj xeeb tshaj yog haum rau kev pleev xim rau lub caij ntuj sov lossis huab cua qhuav.
Txawm hais tias HEC kuj muaj qee yam kev ua haujlwm khaws dej, qhov cuam tshuam no me ntsis qis dua HPMC, tshwj xeeb tshaj yog nyob rau hauv qhov kub thiab txias thiab cua ceev. Nws qhov kev khaws dej tsis txaus yuav ua rau qhuav sai tom qab kev tsim kho, yog li cuam tshuam rau qhov ceev thiab qhov tiaj tus ntawm cov txheej.
4. Kev tiv thaiv enzyme thiab biodegradability
HEC muaj cov ntsiab lus siab ntawm cov hydroxyethyl pawg hauv nws cov qauv thiab yooj yim rau kev puas tsuaj los ntawm cov kab mob me me. Yog li ntawd, nws cov enzyme tsis zoo, tshwj xeeb tshaj yog thaum khaws cia ntev, nws yuav ua rau puas tsuaj, thiab cov tshuaj preservatives yuav tsum tau ntxiv kom ntev lub sijhawm khaws cia.
HPMC muaj kev tiv thaiv enzyme zoo dua li HEC thiab ruaj khov dua. Nws yog qhov tshwj xeeb tshaj yog rau cov txheej txheem kev lag luam uas muaj kev ruaj khov cia khoom siab.
5. Tus nqi thiab kev siv ua lag luam
Los ntawm qhov pom ntawm tus nqi, HEC pheej yig dua thiab tsim nyog rau cov khoom siv loj, pheej yig. Nws cov nyhuv thickening zoo thiab fluidity ua rau nws muaj feem ntau hauv kev lag luam hauv cov ntawv thov xws li cov txheej txheem phab ntsa sab hauv thiab cov xim latex qis.
Txawm hais tias HPMC kim dua me ntsis, nws qhov kev ua tau zoo heev ua rau nws siv dav hauv nruab nrab mus rau qib siab, tshwj xeeb tshaj yog thaum muaj kev xav tau siab rau kev ua haujlwm ntawm kev tsim kho, tiv thaiv kev sagging thiab khaws dej, xws li cov txheej txheem phab ntsa sab nraud, cov txheej txheem elastic, thiab cov txheej txheem tiv thaiv huab cua.
6. Ib puag ncig thiab kev nyab xeeb
Ob qho tib si yog cov non-ionic cellulose ethers, muaj kev sib raug zoo rau ib puag ncig thiab biodegradability, tsis muaj cov organic compounds volatile (VOCs), thiab yog nyob rau hauv kab nrog kev loj hlob ntawm ntsuab thiab ib puag ncig zoo coatings. Txawm li cas los xij, thaum lub sijhawm siv, yuav tsum tau them sai sai rau nws cov plua plav thiab hygroscopicity, thiab yuav tsum tau ua kom muaj kev tiv thaiv kev ua haujlwm tsim nyog.
HECthiabHPMCtxhua tus muaj lawv tus kheej qhov zoo hauv kev siv txheej. HEC yog qhov tsim nyog dua rau cov khoom txheej uas tsom mus rau kev tswj tus nqi thiab muaj cov kev xav tau siab rau kev ua haujlwm ntawm kev tsim kho; thaum HPMC siv dav hauv cov txheej txheem nruab nrab-rau-siab kawg nrog cov kev xav tau kev ua tau zoo dua vim nws cov dej khaws cia zoo dua, tiv thaiv kev poob qis thiab kev ua haujlwm ntawm kev tsim kho. Hauv cov ntawv thov tiag tiag, HEC lossis HPMC yuav tsum tau xaiv raws li cov yam ntxwv xws li cov kev xav tau kev ua tau zoo ntawm cov mis txheej, cov txheej txheem tsim kho thiab cov huab cua, thiab tuaj yeem siv ua ke raws li qhov xav tau kom ua tiav kev ua tau zoo dua.
Lub sijhawm tshaj tawm: Tsib Hlis-27-2025