Methyl Cellulose (MC) Molecular formula \[C6H7O2(OH)3-h(OCH3)n1] x thonje yoyengedwa imapangidwa ndi alkali, ndipo methyl chloride imagwiritsidwa ntchito ngati etherification agent. Pambuyo pazochitika zingapo, chithandizo cha cellulose ether chikuchitika. Nthawi zambiri, digiri yoloweza m'malo ndi 1.6 ~ 2.0, ndipo kuchuluka kwa m'malo kumakhala kosiyana. Ndi ya non-ionic cellulose ether.
1. Methylcellulose imasungunuka m'madzi ozizira, madzi otentha amakumana ndi zovuta, ndipo pH yamtundu wamadzimadzi imakhala yokhazikika pakati pa 3/12. Wowuma, chingamu ndi zina zambiri zopangira ma surfactants zimagwirizana kwambiri. Gelation imachitika pamene kutentha kufika kutentha kwa gelation.
Kusungidwa kwa madzi kwa methylcellulose kumadalira kuchuluka kwake, kukhuthala, kukongola kwa tinthu ndi kusungunuka kwake. Nthawi zambiri anakulitsa, yaing'ono, mkulu mamasukidwe akayendedwe, mkulu madzi posungira. Pakati pawo, kusungirako madzi kumakhudza kwambiri, ndipo msinkhu wa viscosity suli wofanana mwachindunji ndi kusungirako madzi. The Kusungunuka mlingo makamaka zimadalira mlingo wa padziko kusinthidwa kwa mapadi particles ndi fineness wa particles. Pakati pa ma cellulose ethers omwe ali pamwambawa, methyl cellulose ndi hydroxypropyl methyl cellulose ali ndi kusungirako madzi kwambiri.
Kusintha kwa kutentha kumatha kukhudza kwambiri kusungidwa kwa madzi a methyl cellulose. - Kutentha kwapamwamba, kumapangitsa kuti madzi asungidwe kwambiri. Ngati kutentha kwa matope kupitirira 40 ° C, kusungirako madzi kwa methyl cellulose kudzachepetsedwa kwambiri, zomwe zimakhudza kwambiri kupanga matope.
Methylcellulose amakhudza kwambiri workability ndi adhesion wa matope. "Kumamatira" apa kumatanthauza kumamatira pakati pa chida chopangira ntchito ndi gawo lapansi la khoma, ndiko kuti, kukana kukameta ubweya wa matope. Viscosity, mphamvu yometa ubweya wamatope, ndi mphamvu zomwe ogwira ntchito omwe akugwiritsa ntchito ndizofunikira kwambiri, ndipo kupanga matope sikwabwino. Methylcellulose amamatira pamlingo wocheperako muzinthu za cellulose ether.
2. Hydroxypropyl methylcellulose (HPMC) [C 6 H 7 O 2 (OH) 3-mn (OCH 3 ) m, OCH 2 CH (OH) CH 3 ] n]] hydroxypropyl methyl cellulose M'zaka zaposachedwapa, mitundu ya cellulose ili ndi chinawonjezeka mofulumira. Ndi cellulose yopanda ionic yosakanikirana ndi ether yokonzedwa ndi machitidwe angapo pambuyo pa alkalization ya alkali yoyengedwa ya thonje, momwe propylene oxide ndi methyl chloride amagwiritsidwa ntchito ngati etherification agents. Mlingo wolowa m'malo nthawi zambiri ndi 1.2 / 2.0. Makhalidwe ake amasiyana malinga ndi kuchuluka kwa methoxyl ndi hydroxypropyl.
1. Hydroxypropyl methylcellulose imagawidwa mumtundu wotentha-wosungunuka ndi mtundu wanthawi yomweyo. Kutentha kwake kwa gelation m'madzi otentha ndipamwamba kwambiri kuposa methylcellulose. Ikuwonetsanso kusintha kwakukulu pa methylcellulose ikasungunuka m'madzi ozizira.
Kukhuthala kwa hydroxypropyl methylcellulose kumakhudzana ndi kulemera kwa maselo, ndipo kulemera kwa maselo ndikokwera. Kutentha kumakhudzanso kukhuthala kwake, pamene kutentha kumawonjezeka, kukhuthala kumachepa. Komabe, mphamvu ya kutentha pa viscosity ndiyotsika kuposa ya methyl cellulose. Yankho lake ndi kusunga khola kutentha firiji.
3. Kusungidwa kwa madzi kwa hydroxypropyl methylcellulose kumadalira kuchuluka kwake, kukhuthala kwake, ndi zina zotero, ndipo madzi osungira madzi omwewo ndi apamwamba kuposa a methyl cellulose.
4. Hydroxypropyl methylcellulose ndi yokhazikika kwa asidi ndi alkali, ndipo njira yake yamadzimadzi imakhala yokhazikika kwambiri mu pH ya 2/12. Kuchita kwa caustic koloko ndi madzi a mandimu alibe mphamvu zambiri, koma zamchere zimatha kufulumizitsa kusungunuka kwake, ndipo kukhuthala kumawonjezeka. Hydroxypropyl methylcellulose ndi yokhazikika ku mchere wamba, koma pamene mchere wa mchere uli wambiri, kukhuthala kwa hydroxypropyl methylcellulose solution kumawonjezeka.
Hydroxypropyl methylcellulose imatha kusakanikirana ndi ma polima osungunuka ndi madzi kuti apange njira yofananira, yowoneka bwino kwambiri. Monga polyvinyl mowa, wowuma ether, masamba chingamu, etc.
Hydroxypropyl methylcellulose imakhala ndi kukana bwino kwa enzyme kuposa methylcellulose, kuthekera kwa kuwonongeka kwa enzymatic kwa yankho lake ndikotsika kuposa methylcellulose, ndipo kumamatira kwa hydroxypropylmethylcellulose kumapangidwe amatope ndikokwera kuposa methylcellulose. cellulose yoyambira.
Chachitatu, hydroxyethyl cellulose (HEC) amapangidwa kuchokera ku thonje loyengedwa ndi alkali, pamaso pa acetone, ndi ethylene oxide ngati etherification agent. Madigiri ake olowa m'malo nthawi zambiri amakhala 1.5 / 2.0. Ili ndi hydrophilicity yamphamvu ndipo ndiyosavuta kuyamwa chinyezi.
1. Hydroxyethyl cellulose imasungunuka m'madzi ozizira, koma ndizovuta kusungunuka m'madzi otentha. Njira yothetsera vutoli imakhala yokhazikika pa kutentha kwakukulu ndipo ilibe katundu wa gel. Ikhoza kugwiritsidwa ntchito kwa nthawi yaitali mumatope otentha kwambiri, koma kusungirako madzi kumakhala kochepa kusiyana ndi methyl cellulose.
2. Ma cellulose a Hydroxyethyl ndi okhazikika ku asidi ambiri ndi zamchere. Alkali imathandizira kusungunuka kwake, ndipo kukhuthala kwake kumawonjezeka pang'ono. Kubalalika kwake m'madzi ndikoyipa pang'ono kuposa methyl cellulose ndi hydroxypropyl methyl cellulose.
3. Hydroxyethyl cellulose imakhala ndi ntchito yabwino yoletsa kupachikidwa pamatope, koma kwa nthawi yaitali, hydroxyethyl cellulose yomwe imapangidwa m'nyumba imakhala yochepa kwambiri kuposa methyl cellulose chifukwa cha madzi ake ambiri komanso phulusa lambiri.
4. Carboxymethyl cellulose (CMC) \ [C6H7O2 (OH) 2och2COONa] (thonje, etc.) ya fiber yachilengedwe imathandizidwa ndi alkali, ndipo sodium chloroacetate imagwiritsidwa ntchito ngati etherification agent, pambuyo pochita chithandizo chamankhwala, imapangidwa kukhala ionic. cellulose ether. Mlingo wolowa m'malo nthawi zambiri umakhala 0.4 / 1.4, ndipo kuchuluka kwa kulowetsa kumakhudza kwambiri magwiridwe antchito.
Carboxymethyl cellulose imakhala ndi hygroscopicity yayikulu, ndipo malo osungira amakhala ndi madzi ambiri.
2. Carboxymethyl cellulose amadzimadzi amadzimadzi samatulutsa gel osakaniza, mamasukidwe akayendedwe amachepetsa pamene kutentha kukwera, ndipo mamasukidwe akayendedwe ndi wosasinthika pamene kutentha kuposa 50 ° C.
Kukhazikika kwake kumakhudzidwa kwambiri ndi pH. Nthawi zambiri amagwiritsidwa ntchito ngati matope a gypsum, osati matope a simenti. Pankhani ya high alkalinity, idzataya mamasukidwe ake.
Kusungidwa kwa madzi ake ndikotsika kwambiri kuposa methyl cellulose. Mtondo wa Gypsum umachepetsa mphamvu, umachepetsa mphamvu. Koma mtengo wa carboxymethyl cellulose ndi wotsika kwambiri kuposa wa methyl cellulose.
Nthawi yotumiza: Jan-13-2023