1. Methylcellulose (MC)
Thonje loyengedwa likaphikidwa ndi alkali, cellulose ether imapangidwa kudzera mu njira zosiyanasiyana zomwe zimagwiritsidwa ntchito ndi methane chloride ngati etherification. Kawirikawiri, mlingo wa kusintha ndi 1.6 ~ 2.0, ndipo kusungunuka kumasiyananso ndi madigiri osiyanasiyana a kusintha. Ndi ya non-ionic cellulose ether.
(1) Methylcellulose imasungunuka m'madzi ozizira, ndipo zimakhala zovuta kusungunuka m'madzi otentha. Madzi ake ndi olimba kwambiri pa pH = 3 ~ 12. Imagwirizana bwino ndi starch, guar gum, ndi zina zotero. Kutentha kukafika pa kutentha kwa gelation, gelation imachitika.
(2) Kusunga madzi kwa methyl cellulose kumadalira kuchuluka kwake kowonjezera, kukhuthala, kusalala kwa tinthu tating'onoting'ono ndi kuchuluka kwa kusungunuka. Kawirikawiri, ngati kuchuluka kowonjezera kuli kwakukulu, kusalala kwake kuli kochepa, ndipo kukhuthala kwake kuli kwakukulu, kuchuluka kwa kusungunuka kwa madzi kumakhala kwakukulu. Pakati pawo, kuchuluka kwa kuwonjezeredwa kumakhudza kwambiri kuchuluka kwa kusungunuka kwa madzi, ndipo kuchuluka kwa kukhuthala sikufanana mwachindunji ndi kuchuluka kwa kusungunuka kwa madzi. Kusungunuka kwa madzi kumadalira makamaka kuchuluka kwa kusintha kwa pamwamba pa tinthu tating'onoting'ono ta cellulose ndi kusalala kwa tinthu tating'onoting'ono. Pakati pa ma cellulose ether omwe ali pamwambapa, methyl cellulose ndi hydroxypropyl methyl cellulose zili ndi kuchuluka kwa kusungunuka kwa madzi.
(3) Kusintha kwa kutentha kudzakhudza kwambiri kuchuluka kwa madzi omwe amasungidwa mu methyl cellulose. Nthawi zambiri, kutentha kukakhala kwakukulu, madzi omwe amasungidwa amakhala oipa kwambiri. Ngati kutentha kwa matope kupitirira 40°C, madzi omwe amasungidwa mu methyl cellulose adzachepa kwambiri, zomwe zidzakhudza kwambiri kapangidwe ka matopewo.
(4) Methyl cellulose imakhudza kwambiri kapangidwe ndi kumatirira kwa matope. "Kumatirira" apa kumatanthauza mphamvu yomatirira yomwe imamveka pakati pa chida chogwiritsira ntchito cha wantchito ndi khoma, ndiko kuti, kukana kukatira kwa matope. Kumatirira kwake ndi kwakukulu, kukana kukatira kwa matope ndi kwakukulu, ndipo mphamvu zomwe ogwira ntchito amafunikira pakugwiritsa ntchito matope ndi zazikulu, ndipo magwiridwe antchito a matope ndi otsika. Kumatirira kwa methyl cellulose kuli pamlingo wocheperako muzinthu zopangidwa ndi cellulose ether.
2. Hydroxypropylmethylcellulose (HPMC)
Hydroxypropyl methylcellulose ndi mtundu wa cellulose womwe kutulutsa ndi kugwiritsa ntchito kwake kwakhala kukukwera mofulumira m'zaka zaposachedwa. Ndi ether yosakanikirana ya cellulose yosakhala ionic yopangidwa kuchokera ku thonje loyengedwa pambuyo pa alkalization, pogwiritsa ntchito propylene oxide ndi methyl chloride ngati etherification, kudzera muzochita zingapo. Mlingo wa kusintha nthawi zambiri umakhala 1.2 ~ 2.0. Katundu wake ndi wosiyana chifukwa cha kusiyana kwa kuchuluka kwa methoxyl ndi kuchuluka kwa hydroxypropyl.
(1) Hydroxypropyl methylcellulose imasungunuka mosavuta m'madzi ozizira, ndipo imakumana ndi zovuta kusungunuka m'madzi otentha. Koma kutentha kwake kwa gelation m'madzi otentha ndi kwakukulu kwambiri kuposa kwa methyl cellulose. Kusungunuka m'madzi ozizira nakonso kumawonjezeka kwambiri poyerekeza ndi methyl cellulose.
(2) Kukhuthala kwa hydroxypropyl methylcellulose kumagwirizana ndi kulemera kwake kwa mamolekyulu, ndipo kulemera kwa mamolekyulu kukakhala kwakukulu, kukhuthala kumakhala kwakukulu. Kutentha kumakhudzanso kukhuthala kwake, pamene kutentha kukukwera, kukhuthala kumachepa. Komabe, kukhuthala kwake kwakukulu kumakhala ndi kutentha kochepa kuposa methyl cellulose. Yankho lake ndi lokhazikika likasungidwa kutentha kwa chipinda.
(3) Kusunga madzi kwa hydroxypropyl methylcellulose kumadalira kuchuluka kwake kowonjezera, kukhuthala kwake, ndi zina zotero, ndipo kuchuluka kwake kosungira madzi pansi pa kuchuluka komweko kowonjezera kumakhala kwakukulu kuposa kwa methyl cellulose.
(4) Hydroxypropyl methylcellulose ndi yokhazikika ku asidi ndi alkali, ndipo yankho lake lamadzi ndi lokhazikika kwambiri pa pH = 2 ~ 12. Caustic soda ndi madzi a laimu sizikhudza kwambiri magwiridwe ake, koma alkali imatha kufulumizitsa kusungunuka kwake ndikuwonjezera kukhuthala kwake. Hydroxypropyl methylcellulose ndi yokhazikika ku mchere wamba, koma pamene kuchuluka kwa mchere kuli kwakukulu, kukhuthala kwa yankho la hydroxypropyl methylcellulose kumawonjezeka.
(5) Hydroxypropyl methylcellulose ikhoza kusakanikirana ndi mankhwala a polymer osungunuka m'madzi kuti apange yankho lofanana komanso lokhuthala kwambiri. Monga polyvinyl alcohol, starch ether, vegetable gum, ndi zina zotero.
(6) Hydroxypropyl methylcellulose ili ndi kukana bwino kwa ma enzyme kuposa methylcellulose, ndipo yankho lake silingathe kuwonongeka ndi ma enzyme kuposa methylcellulose. Kugwirizana kwa hydroxypropyl methylcellulose ku matope ndi kwakukulu kuposa kwa methylcellulose.
3. Hydroxyethyl cellulose (HEC)
Imapangidwa kuchokera ku thonje loyengedwa bwino lomwe limaphikidwa ndi alkali, ndipo imayatsidwa ndi ethylene oxide ngati etherification ngati pali acetone. Mlingo wa kusintha nthawi zambiri umakhala 1.5 ~ 2.0. Ili ndi hydrophilicity yamphamvu ndipo imayamwa mosavuta chinyezi.
(1) Hydroxyethyl cellulose imasungunuka m'madzi ozizira, koma imakhala yovuta kusungunuka m'madzi otentha. Yankho lake ndi lokhazikika kutentha kwambiri popanda gelling. Itha kugwiritsidwa ntchito kwa nthawi yayitali kutentha kwambiri mu mortar, koma kusunga kwake madzi ndi kochepa kuposa kwa methyl cellulose.
(2) Hydroxyethyl cellulose imakhala yokhazikika ku asidi wamba ndi alkali. Alkali imatha kufulumizitsa kusungunuka kwake ndikuwonjezera kukhuthala kwake pang'ono. Kufalikira kwake m'madzi ndikoipa pang'ono kuposa kwa methyl cellulose ndi hydroxypropyl methyl cellulose.
(3) Hydroxyethyl cellulose ili ndi mphamvu yabwino yoletsa kutsika kwa matope, koma simenti imachedwa kutsika nthawi yayitali.
(4) Kagwiridwe ka ntchito ka hydroxyethyl cellulose komwe kamapangidwa ndi mabizinesi ena am'nyumba n'kotsika poyerekeza ndi ka methyl cellulose chifukwa cha kuchuluka kwa madzi ndi phulusa.
4. Carboxymethyl cellulose (CMC)
Ionic cellulose ether imapangidwa kuchokera ku ulusi wachilengedwe (thonje, ndi zina zotero) wothiridwa ndi alkali ndipo imagwiritsidwa ntchito ngati etherification kudzera mu njira zingapo zochiritsira. Mlingo wa kusintha nthawi zambiri umakhala 0.4 ~ 1.4, ndipo magwiridwe antchito ake amakhudzidwa kwambiri ndi kuchuluka kwa kusintha.
(1) Carboxymethyl cellulose ndi yopyapyala kwambiri, ndipo imakhala ndi madzi ambiri ikasungidwa bwino.
(2) Madzi a Carboxymethyl cellulose sapanga gel, ndipo kukhuthala kudzachepa kutentha kukakwera. Kutentha kukapitirira 50°C, kukhuthala sikungasinthe.
(3) Kukhazikika kwake kumakhudzidwa kwambiri ndi pH. Kawirikawiri, ingagwiritsidwe ntchito mu matope opangidwa ndi gypsum, koma osati mu matope opangidwa ndi simenti. Ikakhala ndi alkaline yambiri, imataya kukhuthala.
(4) Kusunga kwake madzi ndi kotsika kwambiri kuposa kwa methyl cellulose. Kumachedwetsa ntchito ya matope okhala ndi gypsum ndipo kumachepetsa mphamvu yake. Komabe, mtengo wa carboxymethyl cellulose ndi wotsika kwambiri kuposa wa methyl cellulose.
Nthawi yotumizira: Januwale-10-2023