Cellulose ether ndi polima wopangidwa kuchokera ku cellulose wachilengedwe kudzera mukusintha kwamankhwala.Cellulose ether ndi chochokera ku cellulose yachilengedwe.Kupanga kwa cellulose ether ndikosiyana ndi ma polima opangira.Zinthu zake zofunika kwambiri ndi cellulose, gulu lachilengedwe la polima.Chifukwa cha mawonekedwe achilengedwe a cellulose, cellulose palokha sangathe kuchitapo kanthu ndi etherification agents.Komabe, pambuyo pochiza chotupa chotupa, zomangira zamphamvu za haidrojeni pakati pa unyolo wa maselo ndi unyolo zimawonongeka, ndipo kutulutsa kogwira kwa gulu la hydroxyl kumakhala cellulose yotakata.Pezani cellulose ether.
Mu okonzeka kusakaniza matope, kuwonjezera kuchuluka kwa mapadi ether ndi otsika kwambiri, koma akhoza kwambiri kusintha ntchito ya chonyowa matope, ndipo ndi chowonjezera chachikulu chimene chimakhudza ntchito yomanga matope.Kusankhidwa koyenera kwa ma cellulose ethers amitundu yosiyanasiyana, ma viscosity osiyanasiyana, makulidwe osiyanasiyana a tinthu, magawo osiyanasiyana a mamasukidwe akayendedwe ndi kuchuluka kowonjezera kudzakhala ndi zotsatira zabwino pakuchita bwino kwa matope owuma a ufa.Pakalipano, matope ambiri omanga ndi pulasitala sakhala ndi ntchito yabwino yosungira madzi, ndipo matope amadzi amalekanitsidwa pakangopita mphindi zochepa.
Kusungirako madzi ndi ntchito yofunikira ya methyl cellulose ether, komanso ndikuchitanso komwe opanga matope ambiri am'nyumba, makamaka omwe ali kumadera akum'mwera komwe kumatentha kwambiri, amalabadira.Zomwe zimakhudza momwe madzi amasungiramo matope owuma akuphatikizapo kuchuluka kwa MC yowonjezeredwa, kukhuthala kwa MC, kununkhira kwa tinthu tating'ono komanso kutentha kwa chilengedwe.
Makhalidwe a cellulose ethers amadalira mtundu, chiwerengero ndi kugawa kwa zolowa m'malo.Magulu a cellulose ethers amatengeranso mtundu wa zolowa m'malo, digiri ya etherification, solubility ndi ntchito zofananira.Malinga ndi mtundu wa zolowa m'malo pa unyolo wa maselo, zitha kugawidwa mu monoether ndi ether wosakanikirana.MC yomwe timagwiritsa ntchito nthawi zambiri ndi monoether, ndipo HPMC ndi ether yosakanikirana.Methyl cellulose ether MC ndi chinthu chopangidwa pambuyo poti gulu la hydroxyl pagawo la shuga la cellulose wachilengedwe lilowe m'malo ndi methoxy.Kapangidwe kake ndi [COH7O2(OH)3-h(OCH3)h ]x.Gawo la gulu la hydroxyl pa unit limalowetsedwa ndi gulu la methoxy, ndipo gawo lina limasinthidwa ndi gulu la hydroxypropyl, mawonekedwe ake ndi [C6H7O2(OH)3-mn(OCH3)m[OCH2CH(OH)CH3] n] x Ethyl methyl cellulose ether HEMC, iyi ndi mitundu ikuluikulu yomwe imagwiritsidwa ntchito kwambiri ndikugulitsidwa pamsika.
Pankhani ya solubility, imatha kugawidwa kukhala ionic ndi non-ionic.Ma etha osungunuka m'madzi omwe si a ionic cellulose amapangidwa makamaka ndi ma alkyl ethers ndi ma hydroxyalkyl ethers.Ionic CMC imagwiritsidwa ntchito makamaka mu zotsukira zopangira, kusindikiza nsalu ndi utoto, kufufuza zakudya ndi mafuta.Non-ionic MC, HPMC, HEMC, etc. amagwiritsidwa ntchito makamaka muzomangamanga, zokutira latex, mankhwala, mankhwala tsiku ndi tsiku, etc. Amagwiritsidwa ntchito ngati thickener, madzi kusunga wothandizira, stabilizer, dispersant ndi filimu kupanga wothandizira.
Kusungirako madzi a cellulose ether: Popanga zida zomangira, makamaka matope a ufa wowuma, ether ya cellulose imagwira ntchito yosasinthika, makamaka popanga matope apadera (matope osinthidwa), ndi gawo lofunikira komanso lofunikira .Ntchito yofunikira ya cellulose ether yosungunuka m'madzi mumatope imakhala ndi mbali zitatu:
1. Mphamvu yabwino yosungira madzi
2. Mmene matope kusasinthasintha ndi thixotropy
3. Kulumikizana ndi simenti.
Mphamvu yosungira madzi ya cellulose ether imatengera kuyamwa kwamadzi kwa gawo loyambira, kapangidwe ka matope, makulidwe a matope, kuchuluka kwa madzi amatope, komanso nthawi yoyikapo.Kusungidwa kwamadzi kwa cellulose ether komweko kumachokera ku kusungunuka ndi kutaya madzi m'thupi kwa cellulose ether yokha.Monga ife tonse tikudziwa, ngakhale cellulose maselo unyolo muli ambiri hydratable OH magulu kwambiri hydratable, si sungunuka m'madzi, chifukwa mapadi kapangidwe ndi mkulu digiri crystallinity.Mphamvu ya hydration yamagulu a hydroxyl yokha sikokwanira kuphimba zomangira zamphamvu za haidrojeni ndi mphamvu za van der Waals pakati pa mamolekyu.Choncho, zimangotupa koma sizisungunuka m'madzi.Pamene cholowa m'malo anadzetsa mu unyolo maselo, osati m'malo kuwononga haidrojeni unyolo, komanso interchain wa haidrojeni chomangira anawonongedwa chifukwa wedging wa m'malo pakati moyandikana unyolo.Cholowa m'malo chimakhala chachikulu, ndiye kuti mtunda wapakati pa mamolekyu ndi waukulu.Kuchuluka kwa mtunda.Zotsatira zazikulu za kuwononga zomangira za haidrojeni, cellulose ether imakhala yosungunuka m'madzi pambuyo poti latisi ya cellulose ikukula ndipo yankho limalowa, ndikupanga yankho lapamwamba kwambiri.Kutentha kukakwera, hydration ya polima imafooka, ndipo madzi pakati pa maunyolo amathamangitsidwa.Pamene kuchepa kwa madzi m'thupi kumakhala kokwanira, mamolekyu amayamba kusonkhana, kupanga gel osakaniza maukonde atatu ndi kupindidwa.
Nthawi yotumiza: Dec-06-2022