Methylcellulose (MC)
Maselo a methylcellulose (MC) ndi awa:
[C6H7O2(OH)3-h(OCH3)n\]x
Njira yopangira ndi kupanga cellulose ether kudzera muzochita zingapo pambuyo poti thonje loyengedwa limagwiritsidwa ntchito ndi alkali, ndipo methyl chloride imagwiritsidwa ntchito ngati etherification agent.Nthawi zambiri, kuchuluka kwa m'malo ndi 1.6 ~ 2.0, ndipo kusungunuka kwake kumasiyananso ndi magawo osiyanasiyana olowa m'malo.Ndi ya non-ionic cellulose ether.
Methylcellulose imasungunuka m'madzi ozizira, ndipo zimakhala zovuta kusungunuka m'madzi otentha.Njira yake yamadzimadzi imakhala yokhazikika pa pH = 3 ~ 12.
Iwo ali ngakhale bwino ndi wowuma, guar chingamu, etc. ndi surfactants ambiri.Pamene kutentha kufika kutentha kwa gelation, gelation imachitika.
Kusungidwa kwa madzi kwa methylcellulose kumadalira kuchuluka kwake, kukhuthala, kukongola kwa tinthu ndi kusungunuka kwake.
Nthawi zambiri, ngati kuchuluka kwake kuli kwakukulu, fineness ndi yaying'ono, ndipo mamasukidwe ake ndiakuluakulu, kuchuluka kwa kusunga madzi kumakhala kwakukulu.Pakati pawo, kuchuluka kwa kuwonjezera kumakhudza kwambiri kuchuluka kwa kusungirako madzi, ndipo msinkhu wa viscosity suli wofanana mwachindunji ndi mlingo wa kusunga madzi.The Kusungunuka mlingo makamaka zimadalira mlingo wa padziko kusinthidwa kwa mapadi particles ndi tinthu fineness.
Pakati pa ma cellulose ethers omwe ali pamwambawa, methyl cellulose ndi hydroxypropyl methyl cellulose ali ndi milingo yayikulu yosungira madzi.
Carboxymethylcellulose (CMC)
Carboxymethyl cellulose, yomwe imadziwikanso kuti sodium carboxymethyl cellulose, yomwe imadziwikanso kuti cellulose, cmc, ndi zina zambiri, ndi polymer ya anionic linear, mchere wa sodium wa cellulose carboxylate, ndipo ndi wongowonjezedwanso komanso wosatha.Chemical zopangira.
Amagwiritsidwa ntchito makamaka m'makampani otsukira, mafakitale azakudya komanso pobowola mafuta m'munda, ndipo kuchuluka kwa zodzoladzola kumangotengera pafupifupi 1%.
Ionic cellulose ether imapangidwa kuchokera ku ulusi wachilengedwe (thonje, etc.) pambuyo pa mankhwala a alkali, pogwiritsa ntchito sodium monochloroacetate monga etherification wothandizira, ndikulandira chithandizo chamankhwala angapo.
Mlingo wolowa m'malo nthawi zambiri ndi 0.4 ~ 1.4, ndipo magwiridwe ake amakhudzidwa kwambiri ndi kuchuluka kwa m'malo.
CMC ili ndi luso lomanga kwambiri, ndipo yankho lake lamadzi lili ndi luso loyimitsa, koma palibe phindu lenileni la pulasitiki.
CMC ikasungunuka, depolymerization imachitika.Kukhuthala kumayamba kuwuka pakutha, kumadutsa pamtunda, kenako kumatsikira kumtunda.Kukhuthala kwake kumakhudzana ndi depolymerization.
Mlingo wa depolymerization umagwirizana kwambiri ndi kuchuluka kwa zosungunulira zosauka (madzi) popanga.Mu dongosolo losasungunuka losungunulira, monga mankhwala otsukira m'mano okhala ndi glycerin ndi madzi, CMC sichitha kuwononga kwathunthu ndipo ifika pamlingo wofanana.
Pankhani ya ndende yamadzi yomwe yapatsidwa, CMC yolowetsedwa kwambiri ndi hydrophilic ndiyosavuta kuyichotsa kuposa CMC yolowa m'malo.
Hydroxyethyl cellulose (HEC)
HEC imapangidwa pochiza thonje loyengedwa ndi alkali, kenako ndikuchita ndi ethylene oxide ngati etherification agent pamaso pa acetone.Mlingo wolowa m'malo nthawi zambiri ndi 1.5 ~ 2.0.Ili ndi hydrophilicity yamphamvu ndipo ndiyosavuta kuyamwa chinyezi.
Hydroxyethyl cellulose imasungunuka m'madzi ozizira, koma ndizovuta kusungunuka m'madzi otentha.Yankho lake ndi khola pa kutentha popanda gelling.
Ndiwokhazikika ku ma acid wamba ndi maziko.Alkalis amatha kufulumizitsa kusungunuka kwake ndikuwonjezera kukhuthala kwake pang'ono.Kuwonongeka kwake m'madzi kumakhala koyipa pang'ono kuposa methyl cellulose ndi hydroxypropyl methyl cellulose.
Hydroxypropyl Methyl Cellulose (HPMC)
The molecular formula of HPMC ndi:
\[C6H7O2(OH)3-mn(OCH3)m,OCH2CH(OH)CH3\]n\]x
Hydroxypropyl methylcellulose ndi mitundu yosiyanasiyana ya cellulose yomwe kutulutsa kwake komanso kumwa kwake kukuchulukirachulukira.
Ndi cellulose yopanda ionic yosakaniza ether yopangidwa kuchokera ku thonje woyengedwa pambuyo pa alkalization, pogwiritsa ntchito propylene oxide ndi methyl chloride monga etherification agent, kupyolera muzotsatira zingapo.Mlingo wolowa m'malo nthawi zambiri ndi 1.2 ~ 2.0.
Katundu wake ndi wosiyana chifukwa cha kuchuluka kwa methoxyl ndi hydroxypropyl.
Hydroxypropyl methylcellulose imasungunuka mosavuta m'madzi ozizira, koma imakumana ndi zovuta pakusungunuka m'madzi otentha.Koma kutentha kwake kwa gelation m'madzi otentha ndikokwera kwambiri kuposa kwa methyl cellulose.Kusungunuka m'madzi ozizira kumakhalanso bwino kwambiri poyerekeza ndi methyl cellulose.
Kukhuthala kwa hydroxypropyl methylcellulose kumakhudzana ndi kulemera kwake kwa maselo, ndipo kukula kwake kwa molekyulu kumapangitsa kukhuthala kwamphamvu.Kutentha kumakhudzanso kukhuthala kwake, pamene kutentha kumawonjezeka, kukhuthala kumachepa.Komabe, kukhuthala kwake kwakukulu kumakhala ndi kutentha kochepa kuposa methyl cellulose.Yankho lake ndi lokhazikika likasungidwa kutentha.
Kusungidwa kwa madzi kwa hydroxypropyl methylcellulose kumadalira kuchuluka kwake, kukhuthala kwake, ndi zina zambiri, komanso kuchuluka kwa madzi omwe amasungidwa pamlingo womwewo ndi wapamwamba kuposa wa methyl cellulose.
Hydroxypropyl methylcellulose ndi yokhazikika ku asidi ndi alkali, ndipo njira yake yamadzimadzi imakhala yokhazikika pa pH = 2 ~ 12.Madzi a caustic ndi laimu sakhala ndi zotsatira zochepa pa ntchito yake, koma alkali amatha kufulumizitsa kusungunuka kwake ndikuwonjezera kukhuthala kwake.
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 mankhwala osungunuka a polima osungunuka m'madzi kuti apange njira yofananira komanso yapamwamba kwambiri.Monga polyvinyl mowa, wowuma ether, masamba chingamu, etc.
Hydroxypropyl methylcellulose imakhala ndi kukana bwino kwa enzyme kuposa methylcellulose, ndipo yankho lake silingawonongeke kwambiri kuposa methylcellulose.
Nthawi yotumiza: Feb-14-2023