Kev tsim cov hydroxyethyl cellulose (HEC) muaj ntau yam tshuaj lom neeg los hloov cov cellulose, ib qho polymer ntuj tsim los ntawm cov nroj tsuag. HEC siv dav hauv ntau yam lag luam, suav nrog tshuaj, tshuaj pleev ib ce, khoom noj, thiab kev tsim kho, vim nws cov khoom ua kom tuab, ruaj khov, thiab khaws dej.
Kev Taw Qhia Txog Hydroxyethyl Cellulose (HEC)
Hydroxyethyl cellulose (HEC) yog ib qho polymer uas tsis yog ionic, yaj hauv dej uas tau los ntawm cellulose los ntawm kev hloov kho tshuaj lom neeg. Nws yog siv dav ua tus neeg sawv cev thickening, gelling, thiab stabilizing hauv ntau yam lag luam.
Cov Khoom Siv Raw
Cellulose: Cov khoom siv raw tseem ceeb rau HEC tsim. Cellulose tuaj yeem tau los ntawm ntau yam khoom siv cog xws li ntoo pulp, paj rwb, lossis cov khoom seem ua liaj ua teb.
Ethylene Oxide (EO): Ib yam tshuaj tseem ceeb uas siv los ua kom cov pab pawg hydroxyethyl nkag mus rau hauv cov cellulose backbone.
Alkali: Feem ntau sodium hydroxide (NaOH) lossis potassium hydroxide (KOH) yog siv los ua catalyst hauv cov tshuaj tiv thaiv.
Cov Txheej Txheem Tsim Khoom
Kev tsim cov HEC suav nrog kev sib xyaw ntawm cellulose nrog ethylene oxide nyob rau hauv alkaline mob.
Cov kauj ruam hauv qab no piav qhia txog cov txheej txheem:
1. Kev kho mob ua ntej ntawm Cellulose
Ua ntej, cellulose raug ntxuav kom huv si kom tshem tawm cov khoom tsis huv xws li lignin, hemicellulose, thiab lwm yam khoom rho tawm. Tom qab ntawd, cov cellulose uas tau ntxuav lawm yuav raug ziab kom qhuav rau qhov dej noo.
2. Kev Ua Haujlwm Etherification
Kev Npaj Cov Tshuaj Alkaline: Ib qho tshuaj aqueous ntawm sodium hydroxide (NaOH) lossis potassium hydroxide (KOH) raug npaj. Qhov concentration ntawm cov tshuaj alkali yog qhov tseem ceeb thiab yuav tsum tau ua kom zoo tshaj plaws raws li qib kev hloov pauv (DS) ntawm cov khoom kawg.
Kev Teeb Tsa Cov Tshuaj: Cov cellulose ntshiab raug faib rau hauv cov kua alkali. Cov khoom sib tov raug cua sov rau qhov kub tshwj xeeb, feem ntau nyob ib puag ncig 50-70 ° C, kom ntseeg tau tias cov cellulose o tag thiab nkag tau rau cov tshuaj.
Ntxiv Ethylene Oxide (EO): Ethylene oxide (EO) maj mam ntxiv rau hauv lub thawv tshuaj thaum tswj qhov kub thiab do tas li. Qhov tshuaj tiv thaiv yog exothermic, yog li kev tswj qhov kub yog qhov tseem ceeb kom tiv thaiv kev kub dhau.
Kev Soj Ntsuam Cov Tshuaj Tiv Thaiv: Kev nce qib ntawm cov tshuaj tiv thaiv raug saib xyuas los ntawm kev tshuaj xyuas cov qauv ntawm lub sijhawm tsis tu ncua. Cov txheej txheem zoo li Fourier-transform infrared spectroscopy (FTIR) tuaj yeem siv los txiav txim siab qib ntawm kev hloov pauv (DS) ntawm hydroxyethyl pawg ntawm cov cellulose backbone.
Kev Ua Kom Tsis Muaj Zog thiab Ntxuav: Thaum twg tau txais DS raws li qhov xav tau, qhov kev ua kom tsis muaj zog los ntawm kev ua kom cov kua qaub alkaline tsis muaj zog nrog cov kua qaub, feem ntau yog acetic acid. Tom qab ntawd, HEC uas tshwm sim los ntawm kev ntxuav kom huv si nrog dej kom tshem tawm cov tshuaj reagents thiab cov khoom tsis huv uas tsis tau ua haujlwm.
3. Kev Ntxuav thiab Kev Ziab
Cov HEC uas ntxuav lawm ces raug lim kom huv dua los ntawm kev lim lossis centrifugation kom tshem tawm cov khoom tsis huv uas tseem tshuav. Cov HEC uas tau ntxuav lawm ces raug ziab kom qhuav rau cov dej noo tshwj xeeb kom tau txais cov khoom kawg.
Kev Tswj Xyuas Zoo
Kev tswj xyuas zoo yog qhov tseem ceeb thoob plaws hauv cov txheej txheem tsim khoom HEC kom ntseeg tau tias cov khoom kawg zoo sib xws thiab huv si. Cov yam ntxwv tseem ceeb uas yuav tsum tau saib xyuas suav nrog:
Qib ntawm kev hloov pauv (DS)
Qhov viscosity
Cov dej noo
pH
Kev huv (tsis muaj impurities)
Cov txheej txheem tshuaj xyuas xws li FTIR, kev ntsuas viscosity, thiab kev tshuaj xyuas elemental feem ntau yog siv rau kev tswj xyuas zoo.
Cov ntawv thov ntawm Hydroxyethyl Cellulose (HEC)
HEC pom cov ntawv thov hauv ntau yam lag luam vim nws cov khoom siv tau ntau yam:
Cov Tshuaj: Siv ua tus neeg sawv cev tuab hauv cov tshuaj haus, cov tshuaj pleev, thiab cov txheej txheem xa tshuaj uas tswj tau.
Cov Tshuaj Pleev Xim: Feem ntau siv rau hauv cov tshuaj pleev, tshuaj pleev, thiab tshuaj zawv plaub hau ua cov khoom ua kom tuab thiab ruaj khov.
Khoom Noj: Ntxiv rau cov khoom noj ua tus neeg sawv cev thickening thiab gelling, emulsifier, thiab stabilizer.
Kev Tsim Kho: Siv rau hauv cov cement-based mortars thiab grouts los txhim kho kev ua haujlwm thiab kev khaws dej.
Kev Xav Txog Ib puag ncig thiab Kev Nyab Xeeb
Kev Cuam Tshuam Ib Puag Ncig: Kev tsim cov HEC suav nrog kev siv cov tshuaj xws li ethylene oxide thiab alkalis, uas tuaj yeem muaj kev cuam tshuam rau ib puag ncig. Kev tswj cov khib nyiab kom zoo thiab kev ua raws li cov cai yog qhov tseem ceeb kom txo qis kev cuam tshuam rau ib puag ncig.
Kev Nyab Xeeb: Ethylene oxide yog ib qho roj uas ua rau kub hnyiab thiab ua rau muaj kev pheej hmoo thaum tuav thiab khaws cia. Yuav tsum muaj cua nkag, khoom siv tiv thaiv tus kheej (PPE), thiab cov txheej txheem kev nyab xeeb kom ntseeg tau tias cov neeg ua haujlwm muaj kev nyab xeeb.
Hydroxyethyl cellulose (HEC) yog ib qho polymer muaj nqis nrog ntau yam kev siv hauv kev lag luam xws li tshuaj mus rau kev tsim kho. Nws cov khoom tsim tawm cuam tshuam nrog kev sib xyaw ntawm cellulose nrog ethylene oxide nyob rau hauv alkaline tej yam kev mob. Kev ntsuas kev tswj xyuas zoo yog qhov tseem ceeb kom ntseeg tau tias qhov sib xws thiab kev huv ntawm cov khoom kawg. Kev xav txog ib puag ncig thiab kev nyab xeeb kuj yuav tsum tau hais txog thoob plaws hauv cov txheej txheem ntau lawm. Los ntawm kev ua raws li cov txheej txheem thiab cov txheej txheem kom raug, HEC tuaj yeem tsim tau zoo thaum txo qis kev cuam tshuam rau ib puag ncig thiab ua kom muaj kev nyab xeeb ntawm cov neeg ua haujlwm.
Phau ntawv qhia no qhia txog cov txheej txheem tsim cov hydroxyethyl cellulose (HEC) kom meej, txij li cov khoom siv raw mus rau kev tswj xyuas zoo thiab kev siv, muab kev nkag siab zoo txog cov txheej txheem tsim cov polymer tseem ceeb no.
Lub sijhawm tshaj tawm: Plaub Hlis-10-2024