Cellulose ether ndi polima wopangidwa ndi cellulose wachilengedwe monga zopangira posintha mankhwala.Ma cellulose ether amachokera ku cellulose yachilengedwe, kupanga cellulose ether ndi polima yopanga ndi yosiyana, zinthu zake zofunika kwambiri ndi mapadi, mankhwala a polima achilengedwe.Chifukwa cha mawonekedwe achilengedwe a cellulose, mapadi pawokha sangathe kuchitapo kanthu ndi etherifying agent.Koma pambuyo mankhwala a wothandizila kutupa, zomangira wamphamvu haidrojeni pakati unyolo maselo ndi unyolo anawonongedwa, ndi ntchito ya hydroxyl gulu anamasulidwa mu alkali mapadi ndi anachita luso, ndi mapadi efa anapezedwa mwa anachita wa etherifying wothandizila - OH gulu mu - KAPENA gulu.
Makhalidwe a cellulose ethers amadalira mtundu, chiwerengero ndi kugawa kwa zolowa m'malo.Magulu a cellulose ether amatengeranso mtundu wa zolowa m'malo, digiri ya etherification, solubility ndi ntchito yofananira imatha kugawidwa.Malinga ndi mtundu wa zolowa m'malo mwa unyolo wa mamolekyulu, imatha kugawidwa kukhala ether imodzi ndi ether yosakanikirana.MC nthawi zambiri imagwiritsidwa ntchito ngati etha imodzi, pomwe HPmc ndi ether yosakanikirana.Methyl cellulose etha MC ndi chilengedwe cellulose shuga wagawo pa hydroxyl ndi methoxide m'malo mankhwala dongosolo chilinganizo [CO H7O2 (OH) 3-H (OCH3) H] X, hydroxypropyl methyl cellulose etha HPmc ndi gawo pa hydroxyl ndi mbali. wa methoxide m'malo, gawo lina la mankhwala hydroxypropyl m'malo, The structural chilinganizo ndi [C6H7O2 (OH) 3-MN (OCH3) M [OCH2CH (OH) CH3] N] X ndi hydroxyethyl methyl cellulose etha HEmc, amene ankagwiritsa ntchito. ndi kugulitsidwa pamsika.
Kuchokera ku solubility akhoza kugawidwa mu mtundu wa ionic ndi mtundu wosakhala wa ionic.Madzi osungunuka omwe si a ionic cellulose ether amapangidwa makamaka ndi alkyl ether ndi hydroxyl alkyl ether mitundu iwiri ya mitundu.Ionic Cmc imagwiritsidwa ntchito kwambiri popangira zotsukira, nsalu, kusindikiza, chakudya ndi kugwiritsa ntchito mafuta.Non-ionic MC, HPmc, HEmc ndi zina zomwe zimagwiritsidwa ntchito makamaka pomanga, zokutira latex, mankhwala, chemistry tsiku ndi tsiku ndi zina.Monga thickening wothandizira, madzi posungira wothandizira, stabilizer, dispersant, filimu kupanga wothandizira.
Kusunga madzi a cellulose ether
Popanga zida zomangira, makamaka matope osakanikirana owuma, ether ya cellulose imagwira ntchito yosasinthika, makamaka popanga matope apadera (matope osinthidwa), ndi gawo lofunika kwambiri.
Ntchito yofunika kwambiri ya madzi sungunuka mapadi etero mu matope makamaka ali mbali zitatu, mmodzi ndi kwambiri madzi posungira luso, chachiwiri ndi chikoka cha matope kusasinthasintha ndi thixotropy, ndipo chachitatu ndi mogwirizana ndi simenti.
Kusungidwa kwa madzi a cellulose ether, kumadalira maziko a hydroscopicity, kapangidwe ka matope, makulidwe a matope, kufunikira kwa madzi amatope, nthawi yopumira.Kusungidwa kwamadzi kwa cellulose ether kumachokera ku kusungunuka ndi kutha kwa cellulose ether komweko.Ndizodziwika bwino kuti maunyolo a cellulose a cellulose, ngakhale ali ndi magulu ambiri a OH omwe ali ndi hydrated kwambiri, sasungunuka m'madzi chifukwa cha mawonekedwe awo a crystalline kwambiri.Mphamvu ya hydration ya magulu a hydroxyl okha sikokwanira kulipira ma intermolecular hydrogen bond ndi mphamvu za van der Waals.Pamene zolowa m'malo anadzetsa mu unyolo maselo, osati m'malo kuwononga unyolo haidrojeni, komanso interchain wa haidrojeni nsinga chifukwa wedging wa m'malo pakati moyandikana unyolo.Kukula kwa zolowa m'malo ndikokulirapo mtunda wapakati pa mamolekyu.The kwambiri chiwonongeko cha haidrojeni chomangira kwenikweni, mapadi latisi kukula, njira mu mapadi efa amakhala madzi sungunuka, mapangidwe mkulu mamasukidwe akayendedwe njira.Pamene kutentha kumakwera, hydration ya polima imachepa ndipo madzi pakati pa maunyolo amatulutsidwa.Pamene kuchepa kwa madzi m'thupi kumakhala kokwanira, mamolekyu amayamba kusonkhana ndipo gel osakaniza amapindika mumagulu atatu.Zomwe zimakhudza kusungidwa kwamadzi mumatope ndi monga cellulose ether viscosity, mlingo, fineness wa tinthu ndi kutentha kwa utumiki.
Kuchuluka kwa mamasukidwe a cellulose ether, kumapangitsa kuti madzi asungidwe bwino, kukhuthala kwa njira ya polima.Kulemera kwa maselo (digiri ya polymerization) ya polima imatsimikiziridwanso ndi kutalika ndi maonekedwe a maselo a unyolo, ndipo kugawidwa kwa chiwerengero cha olowa m'malo kumakhudzanso kukhuthala kwa ma viscosity osiyanasiyana.[eta] = Km alpha
Intrinsic viscosity ya mayankho a polima
M polima molekyulu kulemera
α polima khalidwe mosasintha
K kukhuthala kwamphamvu kokwanira
The mamasukidwe akayendedwe a polima njira zimadalira maselo kulemera kwa polima.The mamasukidwe akayendedwe ndi ndende ya mapadi ether mayankho zikugwirizana ntchito zosiyanasiyana.Choncho, aliyense mapadi efa zambiri zosiyanasiyana kukhuthala kukhuthala, kukhuthala malamulo komanso makamaka mwa kuwonongeka kwa mapadi alkali, ndicho kuthyoka kwa mapadi maselo unyolo kukwaniritsa.
Pa kukula kwa tinthu tating'onoting'ono, tinthu tating'onoting'ono timasunga bwino madzi.Large particles wa mapadi etere kukhudzana ndi madzi, pamwamba yomweyo kupasuka ndi kupanga gel osakaniza kukulunga zinthu kuteteza madzi mamolekyu kupitiriza kudutsa, nthawi zina yaitali yogwira ntchito sangathe wogawana omwazika kusungunuka, mapangidwe matope flocculent njira kapena agglomerate.Kusungunuka kwa cellulose ether ndi chimodzi mwazinthu zomwe mungasankhe cellulose ether.
Kukula ndi thixotropy wa cellulose ether
Zotsatira zachiwiri za cellulose ether - thickening zimadalira: cellulose ether polymerization degree, solution ndende, shear rate, kutentha ndi zina.Katundu wa gelation wa yankho ndi wapadera kwa alkyl cellulose ndi zotuluka zake zosinthidwa.Makhalidwe a gelation amakhudzana ndi kuchuluka kwa kusintha, ndende ya yankho ndi zowonjezera.Pazinthu zosinthidwa za hydroxyl alkyl, katundu wa gel amalumikizananso ndi kuchuluka kwa kusinthidwa kwa hydroxyl alkyl.Pakuti yankho ndende ya otsika mamasukidwe akayendedwe MC ndi HPmc akhoza kukonzekera 10% -15% ndende njira, sing'anga mamasukidwe akayendedwe MC ndi HPmc akhoza kukonzekera 5% -10% njira ndi mkulu mamasukidwe akayendedwe MC ndi HPmc akhoza kukhala okonzeka 2% -3% yankho, ndipo kawirikawiri mamasukidwe akayendedwe a mapadi efa komanso graded ndi 1% -2% njira.Maselo apamwamba a cellulose ether thickener dzuwa, ndende yofanana ya yankho, ma polima osiyanasiyana olemera a maselo ali ndi kukhuthala kosiyana, kukhuthala kwa ma cell ndi kulemera kwa maselo kumatha kufotokozedwa motere, [η] = 2.92 × 10-2 (DPn) 0.905, DPn ndi avareji. polymerization digiri yapamwamba.Otsika maselo olemera mapadi efa kuwonjezera zambiri kukwaniritsa chandamale mamasukidwe akayendedwe.Kukhuthala kwake sikudalira kumeta ubweya wa ubweya, kukhuthala kwakukulu kuti akwaniritse kukhuthala kwa chandamale, kuchuluka komwe kumafunikira kuwonjezera pang'ono, kukhuthala kumadalira kukhuthala kwamphamvu.Chifukwa chake, kuti mukwaniritse kusasinthika kwina, kuchuluka kwa cellulose ether (concentration of solution) ndi ma viscosity yankho ziyenera kutsimikiziridwa.Kutentha kwa gelation kwa yankho kunachepa mofanana ndi kuwonjezeka kwa ndende ya yankho, ndipo gelation inachitika kutentha kwa firiji itatha kufika pamtundu wina.HPmc imakhala ndi ma gelation ambiri kutentha kutentha.
Kusasinthasintha kungasinthidwenso posankha kukula kwa tinthu ndi ma cellulose ethers ndi magawo osiyanasiyana a kusinthidwa.Zomwe zimatchedwa kusinthidwa ndikuyambitsa gulu la hydroxyl alkyl mumlingo wina wolowa m'malo mwa mafupa a MC.Posintha zikhalidwe zolowa m'malo mwazolowa m'malo awiri, ndiko kuti, DS ndi MS m'malo mwa magulu a methoxy ndi hydroxyl.Makhalidwe osiyanasiyana a cellulose ether amafunikira posintha mitundu iwiri ya zolowa m'malo.
mgwirizano pakati pa kusasinthasintha ndi kusintha.Mu Chithunzi 5, kuwonjezera kwa cellulose ether kumakhudza kumwa madzi kwa matope ndikusintha chiŵerengero cha madzi-binder cha madzi ndi simenti, chomwe ndi mphamvu yowonjezereka.Mlingo wokwera kwambiri, m'pamenenso amamwa madzi ambiri.
Ma cellulose ethers omwe amagwiritsidwa ntchito muzomangamanga zaufa ayenera kusungunuka mwachangu m'madzi ozizira ndikupangitsa kuti dongosololi likhale logwirizana.Ngati kumeta ubweya woperekedwa kukadali kosunthika komanso kosalala ndi chinthu chotsika kwambiri kapena chotsika.
Palinso liniya ubale wabwino pakati pa simenti slurry kusasinthasintha ndi mlingo wa mapadi etere, mapadi ether akhoza kwambiri kuonjezera mamasukidwe akayendedwe matope, waukulu mlingo, ndi zoonekeratu zotsatira.
Ma cellulose etere amadzimadzi njira ndi mkulu mamasukidwe akayendedwe ali mkulu thixotropy, amene ndi chimodzi mwa makhalidwe a mapadi efa.Amadzimadzi njira za Mc mtundu ma polima zambiri pseudoplastic, sanali thixotropic fluidity m'munsimu awo gel osakaniza kutentha, koma Newtonian otaya katundu pa otsika kukameta ubweya mitengo.Pseudoplasticity imawonjezeka ndi kuchuluka kwa kulemera kwa maselo kapena kuchuluka kwa cellulose ether ndipo sizidalira mtundu ndi digirii yolowa m'malo.Choncho, ma cellulose ethers a kalasi yofanana ya viscosity, kaya MC, HPmc kapena HEmc, nthawi zonse amasonyeza zofanana za rheological malinga ngati ndende ndi kutentha kumakhalabe kosasintha.Kutentha kumawonjezeka, gel osakaniza amapangidwa ndipo kuthamanga kwa thixotropic kumachitika.Ma cellulose ether okhala ndi ndende yayikulu komanso mawonekedwe otsika amawonetsa thixotropy ngakhale pansi pa kutentha kwa gel osakaniza.Katunduyu ndiwopindulitsa kwambiri pakumanga matope omangira kuti asinthe mayendedwe ake ndi kutuluka kwake komwe kumapachikidwa.Payenera kufotokozedwa apa kuti kukwezeka kwa kukhuthala kwa cellulose ether kumapangitsa kuti madzi asungidwe bwino, koma kukhuthala kwake kumapangitsa kuti pakhale kuchuluka kwa maselo a cellulose ether, kuchepetsedwa kofananira kwa kusungunuka kwake, komwe kumakhudza kwambiri. kuchuluka kwa matope ndi ntchito yomanga.The apamwamba mamasukidwe akayendedwe, zoonekeratu kwambiri thickening zotsatira za matope, koma si wathunthu kufanana ubale.Ena otsika mamasukidwe akayendedwe, koma kusinthidwa mapadi efa kuwongolera structural mphamvu ya chonyowa matope ali ndi ntchito yabwino kwambiri, ndi kuwonjezeka mamasukidwe akayendedwe, mapadi etere madzi posungira bwino.
Nthawi yotumiza: Mar-30-2022