1.Hydroxypropyl methylcellulose (HPMC)ndi cellulose ether yofunikira, yomwe imagwiritsidwa ntchito kwambiri pomanga, mankhwala, chakudya, zodzoladzola ndi zina. HPMC ali thickening zabwino, filimu kupanga, emulsifying, kuyimitsidwa ndi madzi posungira katundu, kotero imagwira ntchito yofunika kwambiri m'mafakitale ambiri. Kupanga kwa HPMC makamaka kumadalira njira zosinthira mankhwala. M'zaka zaposachedwa, ndi kupita patsogolo kwa sayansi ya zamankhwala, njira zopangira zotengera kuwira kwa tizilombo tating'onoting'ono zayambanso kukopa chidwi.
2. Mfundo yopangira mphamvu ya HPMC
Njira yopangira HPMC yachikhalidwe imagwiritsa ntchito mapadi achilengedwe ngati zida zopangira ndipo amapangidwa ndi njira zama mankhwala monga alkalization, etherification ndi kuyenga. Komabe, njirayi imaphatikizapo kuchuluka kwa organic solvents ndi reagents mankhwala, zomwe zimakhudza kwambiri chilengedwe. Choncho, kugwiritsa ntchito tizilombo toyambitsa matenda kuti tipange cellulose ndikuwonjezeranso etherify kwakhala njira yochepetsera zachilengedwe komanso yokhazikika.
Microbial synthesis of cellulose (BC) yakhala nkhani yovuta kwambiri m'zaka zaposachedwa. Mabakiteriya kuphatikizapo Komagataeibacter (monga Komagataeibacter xylinus) ndi Gluconacetobacter amatha kupanga cellulose yoyera kwambiri kudzera mu fermentation. Mabakiteriyawa amagwiritsa ntchito shuga, glycerol kapena magwero ena a kaboni monga gawo laling'ono, kupesa pansi pamikhalidwe yoyenera, ndikutulutsa ma cellulose nanofibers. Ma cellulose a bakiteriya amatha kusinthidwa kukhala HPMC pambuyo pa hydroxypropyl ndi methylation kusinthidwa.
3. Njira yopangira
3.1 Njira yowotchera ya cellulose ya bakiteriya
Kukhathamiritsa kwa njira yowotchera ndikofunikira kuti pakhale zokolola komanso mtundu wa cellulose ya bakiteriya. Njira zazikulu ndi izi:
Kuwunika kwa zovuta ndi kulima: Sankhani mitundu ya cellulose yokolola kwambiri, monga Komagataeibacter xylinus, kuti muwetedwe ndi kukulitsa bwino.
Sing'anga nayonso mphamvu: Perekani magwero a mpweya (shuga, sucrose, xylose), magwero a nayitrogeni (tinthu ta yisiti, peptone), mchere wa inorganic (phosphates, mchere wa magnesium, etc.) ndi owongolera (acetic acid, citric acid) kuti alimbikitse kukula kwa bakiteriya ndi kaphatikizidwe ka cellulose.
Kuwongolera mkhalidwe wa Fermentation: kuphatikiza kutentha (28-30 ℃), pH (4.5-6.0), mulingo wa okosijeni wosungunuka (chikhalidwe choyambitsa kapena chokhazikika), etc.
Kusonkhanitsa ndi kuyeretsa: Pambuyo pa kupesa, cellulose ya bakiteriya imasonkhanitsidwa ndi kusefa, kuchapa, kuyanika ndi masitepe ena, ndipo mabakiteriya otsalira ndi zonyansa zina zimachotsedwa.
3.2 Hydroxypropyl methylation kusinthidwa kwa cellulose
Ma cellulose a bakiteriya omwe adapezedwa amafunika kusinthidwa kuti akhale ndi mawonekedwe a HPMC. Njira zazikulu ndi izi:
Chithandizo cha alkaliization: zilowerereni mulingo woyenera wa yankho la NaOH kuti muwonjezere unyolo wa cellulose ndikuwongolera zomwe zimachitika pambuyo pa etherification.
Etherification reaction: pansi pa kutentha kwapadera ndi mikhalidwe yochititsa chidwi, onjezani propylene oxide (hydroxypropylation) ndi methyl chloride (methylation) kuti m'malo mwa cellulose hydroxyl gulu kupanga HPMC.
Neutralization ndi kuyenga: kuchepetsa ndi asidi pambuyo zimene anachita kuchotsa unreagent mankhwala reagents, ndi kupeza chomaliza pochapa, kusefa ndi kuyanika.
Kuphwanya ndi kuyika: phwanya HPMC kukhala tinthu ting'onoting'ono tomwe timagwirizana ndi zomwe mukufuna, ndikujambula ndikuziyika molingana ndi ma viscosity osiyanasiyana.
4. Njira zamakono zamakono ndi njira zowonjezera
Kuwongolera kwamavuto: sinthani zokolola za cellulose ndi mtundu kudzera muumisiri wama genetic wa tizilombo tating'onoting'ono.
Kukhathamiritsa kwa njira ya Fermentation: gwiritsani ntchito ma bioreactors kuti muwongolere mwamphamvu kuti muwonjezere kupanga kwa cellulose.
Green etherification process: kuchepetsa kugwiritsa ntchito zosungunulira organic ndikupanga matekinoloje oteteza zachilengedwe, monga kusintha kwa ma enzyme catalytic.
Kuwongolera kwamtundu wazinthu: posanthula digirii yolowa m'malo, kusungunuka, mamasukidwe akayendedwe ndi zizindikiro zina za HPMC, kuwonetsetsa kuti ikukwaniritsa zofunikira pakugwiritsa ntchito.
The nayonso mphamvu zochokeraMtengo wa HPMCkupanga njira ali ndi ubwino kukhala zongowonjezwdwa, zachilengedwe wochezeka ndi kothandiza, zomwe zikugwirizana ndi mchitidwe wa umagwirira wobiriwira ndi chitukuko zisathe. Ndi kupita patsogolo kwa biotechnology, ukadaulo uwu ukuyembekezeka kusintha pang'onopang'ono njira zama mankhwala azikhalidwe ndikulimbikitsa kugwiritsa ntchito kwambiri kwa HPMC pantchito yomanga, chakudya, mankhwala, ndi zina zambiri.
Nthawi yotumiza: Apr-11-2025