Cellulose ether ndi gulu lofunika kwambiri la mankhwala a polima, omwe amagwiritsidwa ntchito kwambiri pakupanga, mankhwala, chakudya ndi zina. Pakati pawo, HPMC (hydroxypropyl methylcellulose), MC (methylcellulose), HEC (hydroxyethyl cellulose) ndi CMC (carboxymethyl cellulose) ndi ma ether anayi ofanana a cellulose.
Methyl cellulose (MC):
MC imasungunuka m'madzi ozizira ndipo imakhala yovuta kusungunuka m'madzi otentha. Madzi amadzimadzi amakhala okhazikika kwambiri pa pH = 3 ~ 12, amagwirizana bwino, ndipo amatha kusakanikirana ndi zinthu zosiyanasiyana monga starch ndi guar gum. Kutentha kukafika pa kutentha kwa gelation, gelation imachitika.
Kusunga madzi kwa MC kumadalira kuchuluka kwake kowonjezera, kukhuthala, kusalala kwa tinthu tating'onoting'ono ndi kuchuluka kwa kusungunuka. Kawirikawiri, kuchuluka kwa madzi komwe kumasungidwa kumakhala kwakukulu pamene kuchuluka kwa kuwonjezera kuli kwakukulu, tinthu tating'onoting'ono tomwe tili bwino komanso kukhuthala kuli kwakukulu. Pakati pawo, kuchuluka kwa kuwonjezera kumakhudza kwambiri kuchuluka kwa madzi komwe kumasungidwa, ndipo kuchuluka kwa kukhuthala sikufanana ndi kuchuluka kwa madzi komwe kumasungidwa. Kuchuluka kwa kusungunuka kumadalira makamaka pa mlingo wa kusintha kwa pamwamba ndi kusalala kwa tinthu ta cellulose.
Kusintha kwa kutentha kudzakhudza kwambiri kusunga madzi kwa MC. Nthawi zambiri, kutentha kukakwera, kusunga madzi kumaipiraipira. Ngati kutentha kwa MC kukapitirira 40°C, kusunga madzi kwa MC kudzachepa kwambiri, zomwe zidzakhudza kwambiri momwe MC imagwirira ntchito.
MC imakhudza kwambiri momwe ntchito yomanga imagwirira ntchito komanso momwe matope amamatirira. Pano, "kumatirira" kumatanthauza kugwirizana pakati pa zida zomangira za wogwira ntchito ndi khoma, ndiko kuti, kukana kukakamira kwa matope. Kumatirira kwakukulu, kukana kukakamira kwa matope kumakhala kwakukulu, mphamvu zomwe wogwira ntchito amafunikira panthawi yogwiritsa ntchito, komanso kusagwira bwino ntchito komanga kwa matope. Kumatirira kwa MC kuli pamlingo wapakati pakati pa zinthu zopangidwa ndi cellulose ether.
Hydroxypropyl methylcellulose (HPMC):
HPMC imasungunuka mosavuta m'madzi, koma ingakhale yovuta kusungunuka m'madzi otentha. Komabe, kutentha kwake kwa gelation m'madzi otentha kumakhala kwakukulu kwambiri kuposa kwa MC, ndipo kusungunuka kwake m'madzi ozizira nakonso kuli bwino kuposa kwa MC.
Kukhuthala kwa HPMC kumagwirizana ndi kulemera kwa mamolekyulu, ndipo kukhuthala kumakhala kwakukulu pamene kulemera kwa mamolekyulu kuli kwakukulu. Kutentha kumakhudzanso kukhuthala kwake, ndipo kukhuthala kumachepa pamene kutentha kukukwera, koma kutentha komwe kukhuthala kwake kumachepa kumakhala kotsika kuposa kwa MC. Yankho lake ndi lokhazikika kutentha kwa chipinda.
Kusunga madzi kwa HPMC kumadalira kuchuluka kwa madzi owonjezera ndi kukhuthala kwake, ndi zina zotero. Kuchuluka kwa madzi osungira madzi pa kuchuluka komweko kwa madzi owonjezera ndi kwakukulu kuposa kwa MC.
HPMC ndi yokhazikika ku asidi ndi alkali, ndipo yankho lake lamadzi ndi lokhazikika kwambiri pa pH ya 2 ~ 12. Caustic soda ndi madzi a laimu sizikhudza kwambiri magwiridwe ake, koma alkali imatha kufulumizitsa kusungunuka kwake ndikuwonjezera kukhuthala. HPMC ndi yokhazikika ku mchere wamba, koma pamene kuchuluka kwa mchere kuli kwakukulu, kukhuthala kwa yankho la HPMC kumawonjezeka.
HPMC ikhoza kusakanizidwa ndi mankhwala a polima osungunuka m'madzi kuti apange yankho lofanana komanso lokhuthala kwambiri, monga polyvinyl alcohol, starch ether, vegetable gum, ndi zina zotero.
HPMC ili ndi kukana kwa ma enzyme bwino kuposa MC, ndipo yankho lake silimakhudzidwa kwambiri ndi kuwonongeka kwa ma enzyme kuposa MC. HPMC imamatira bwino ku matope kuposa MC.
Hydroxyethyl cellulose (HEC):
HEC imasungunuka m'madzi ozizira ndipo imakhala yovuta kusungunuka m'madzi otentha. Yankho lake ndi lokhazikika pa kutentha kwambiri ndipo silikhala ndi mphamvu ya gel. Itha kugwiritsidwa ntchito mu matope kwa nthawi yayitali pa kutentha kwambiri, koma kusunga kwake madzi ndi kochepa kuposa MC.
HEC ndi yokhazikika ku ma acid ndi ma alkali ambiri, alkali imatha kufulumizitsa kusungunuka kwake ndikuwonjezera kukhuthala pang'ono, ndipo kufalikira kwake m'madzi ndikotsika pang'ono poyerekeza ndi MC ndi HPMC.
HEC ili ndi ntchito yabwino yoyimitsa matope, koma simentiyo imakhala ndi nthawi yayitali yochedwetsa ntchito.
HEC yopangidwa ndi mabizinesi ena am'nyumba imakhala ndi magwiridwe antchito otsika kuposa MC chifukwa cha kuchuluka kwa madzi ndi phulusa.
Carboxymethyl cellulose (CMC):
CMC ndi ionic cellulose ether yokonzedwa ndi njira zosiyanasiyana zochiritsira pambuyo poti ulusi wachilengedwe (monga thonje) wachiritsidwa ndi alkali ndipo chloroacetic acid imagwiritsidwa ntchito ngati etherifying agent. Mlingo wa kusintha nthawi zambiri umakhala pakati pa 0.4 ndi 1.4, ndipo magwiridwe antchito ake amakhudzidwa kwambiri ndi kuchuluka kwa kusintha.
CMC ili ndi mphamvu zolimbitsa thupi komanso kulimbitsa thupi, ndipo ingagwiritsidwe ntchito mu zakumwa zomwe zili ndi mafuta ndi mapuloteni kuti igwire ntchito yolimbitsa thupi.
CMC imasunga madzi. Mu nyama, buledi, ma buns ophikidwa ndi nthunzi ndi zakudya zina, imatha kukhala ndi gawo pakuwongolera minofu, ndipo ingapangitse madzi kukhala osasinthasintha, kuwonjezera kuchuluka kwa zinthu, komanso kuwonjezera kukoma.
CMC ili ndi mphamvu yopangira jelly ndi jamu.
CMC imatha kupanga filimu pamwamba pa chakudya, yomwe imateteza zipatso ndi ndiwo zamasamba ndipo imawonjezera nthawi yogwiritsira ntchito zipatso ndi ndiwo zamasamba.
Ma cellulose ether awa ali ndi makhalidwe awoawo komanso malo ogwiritsira ntchito. Kusankha zinthu zoyenera kuyenera kutsimikiziridwa malinga ndi zofunikira zinazake zogwiritsira ntchito komanso momwe zinthu zilili.
Nthawi yotumizira: Okutobala-29-2024