Mapangidwe awirima cellulose ethersZaperekedwa mu Zithunzi 1.1 ndi 1.2. Mphesa iliyonse ya β-D-dehydrate ya molekyulu ya cellulose
Gawo la shuga (gawo lobwerezabwereza la cellulose) limalowetsedwa ndi gulu limodzi la ether aliyense pamalo a C (2), C (3) ndi C (6), mwachitsanzo, mpaka atatu.
gulu la ether. Chifukwa cha kukhalapo kwa magulu a hydroxyl, ma cellulose macromolecules ali ndi ma intramolecular ndi intermolecular hydrogen bond, omwe ndi ovuta kusungunuka m'madzi.
Ndipo n'zovuta kupasuka pafupifupi onse organic solvents. Komabe, pambuyo pa etherification ya cellulose, magulu a ether amalowetsedwa mu unyolo wa maselo,
Mwanjira iyi, zomangira za haidrojeni mkati ndi pakati pa mamolekyu a cellulose zimawonongeka, ndipo hydrophilicity yake imapangidwanso bwino, kuti kusungunuka kwake kukhale bwino.
bwino kwambiri. Pakati pawo, Chithunzi 1.1 ndi mawonekedwe a mayunitsi awiri a anhydroglucose a cellulose ether molecular chain, R1-R6=H.
kapena organic m'malo. 1.2 ndi chidutswa cha carboxymethyl hydroxyethyl cellulose cellulose unyolo, digiri ya m'malo carboxymethyl ndi 0.5,4
Digiri yolowa m'malo ya hydroxyethyl ndi 2.0, ndipo digiri ya molar m'malo ndi 3.0.
Pa cholowa chilichonse cha cellulose, kuchuluka kwa etherification yake kumatha kufotokozedwa ngati digiri ya m'malo (DS). zopangidwa ndi ulusi
Zitha kuwoneka kuchokera pamapangidwe a molekyulu yayikulu kuti kuchuluka kwa m'malo kumayambira 0-3. Ndiye kuti, mphete iliyonse ya anhydroglucose ya cellulose
, chiwerengero cha magulu a hydroxyl omwe amalowetsedwa ndi magulu a etherifying a agent. Chifukwa cha gulu la hydroxyalkyl la cellulose, m'malo mwake
Etherification iyenera kuyambikanso kuchokera ku gulu latsopano laulere la hydroxyl. Choncho, mlingo wa m'malo mwa mtundu uwu wa cellulose ether akhoza kufotokozedwa mu moles.
digiri ya kusintha (MS). Zomwe zimatchedwa molar degree of substitution zikuwonetsa kuchuluka kwa etherifying agent yomwe imawonjezeredwa pagawo lililonse la anhydroglucose la cellulose.
Unyinji wapakati wa reactants.
1 Kapangidwe kake ka glucose unit
2 Zidutswa za cellulose ether unyolo wa maselo
1.2.2 Gulu la cellulose ethers
Kaya ma cellulose ether ndi ma ether amodzi kapena ma ether osakanikirana, mawonekedwe ake ndi osiyana. Ma cellulose macromolecules
Ngati gulu la hydroxyl la mphete ya unit lilowa m'malo ndi gulu la hydrophilic, mankhwalawa amatha kukhala ndi digirii yocheperako m'malo ocheperako.
Ili ndi kusungunuka kwamadzi kwina; ngati imalowetsedwa m'malo ndi gulu la hydrophobic, mankhwalawa ali ndi mlingo wina woloweza m'malo pokhapokha pamene chiwerengero cha m'malo chimakhala chochepa.
Zosungunuka m'madzi, zosinthidwa pang'ono m'malo mwa cellulose etherification zimatha kutupa m'madzi, kapena kusungunula muzosakaniza zocheperako za alkali.
pakati.
Malinga ndi mitundu ya zinthu zolowa m'malo, ma cellulose ethers amatha kugawidwa m'magulu atatu: magulu a alkyl, monga methyl cellulose, ethyl cellulose;
Hydroxyalkyls, monga hydroxyethyl cellulose, hydroxypropyl cellulose; ena, monga carboxymethyl mapadi, etc. Ngati ionization
Gulu, ma cellulose ethers amatha kugawidwa kukhala: ionic, monga carboxymethyl cellulose; osakhala ionic, monga hydroxyethyl cellulose; wosakanizidwa
mtundu, monga hydroxyethyl carboxymethyl cellulose. Malinga ndi gulu la solubility, mapadi amatha kugawidwa kukhala: osungunuka m'madzi, monga carboxymethyl cellulose,
Hydroxyethyl cellulose; madzi osasungunuka, monga methyl cellulose, etc.
1.2.3 Katundu ndi kagwiritsidwe ntchito ka cellulose ethers
Cellulose ether ndi mtundu wa mankhwala pambuyo pa kusintha kwa cellulose etherification, ndipo cellulose ether ili ndi zinthu zambiri zofunika kwambiri. monga
Ili ndi mawonekedwe abwino opanga mafilimu; monga phala yosindikizira, imakhala ndi kusungunuka kwamadzi kwabwino, kusungunuka kwa madzi, kusungirako madzi ndi kukhazikika;
5
Plain ether alibe fungo, alibe poizoni, ndipo ali ndi biocompatibility yabwino. Mwa iwo, carboxymethyl cellulose (CMC) ili ndi "industrial monosodium glutamate"
dzina lotchulidwira.
1.2.3.1 Kupanga mafilimu
Mlingo wa etherification wa cellulose ether uli ndi chikoka chachikulu pakupanga filimu monga luso lopanga filimu ndi mphamvu yolumikizana. Cellulose ether
Chifukwa cha mphamvu zake zamakina komanso zogwirizana bwino ndi utomoni wosiyanasiyana, zitha kugwiritsidwa ntchito m'mafilimu apulasitiki, zomatira ndi zinthu zina.
kukonzekera zinthu.
1.2.3.2 Kusungunuka
Chifukwa cha kukhalapo kwa magulu ambiri a hydroxyl pa mphete ya glucose wokhala ndi mpweya, ma cellulose ethers amakhala ndi kusungunuka kwamadzi bwino. ndi
Kutengera cellulose etha m'malo ndi mlingo wa m'malo, palinso kusankha kusankha kwa zosungunulira organic.
1.2.3.3 Kukhuthala
Ma cellulose ether amasungunuka mu njira yamadzimadzi ngati colloid, momwe kuchuluka kwa ma polymerization a cellulose ether kumatsimikizira cellulose.
Kukhuthala kwa ether solution. Mosiyana ndi madzi a Newtonian, kukhuthala kwa ma cellulose ether solution kumasintha ndi kukameta ubweya wa ubweya, ndi
Chifukwa cha mapangidwe a macromolecules, kukhuthala kwa yankho kudzawonjezeka mofulumira ndi kuwonjezeka kwa zinthu zolimba za cellulose ether, komabe kukhuthala kwa njirayo.
Viscosity imachepanso mofulumira ndi kutentha kwakukulu [33].
1.2.3.4 Kutsika
The mapadi ether njira kusungunuka m'madzi kwa kanthawi adzakula mabakiteriya, potero kubala mabakiteriya enzyme ndi kuwononga mapadi ether gawo.
Magulu oyandikana nawo osalowa m'malo a glucose, potero amachepetsa kuchuluka kwa ma macromolecule. Chifukwa chake, ma cellulose ethers
Kusungidwa kwa njira zamadzimadzi kumafuna kuwonjezeredwa kwazinthu zina zotetezera.
Kuphatikiza apo, ma cellulose ethers ali ndi zina zambiri zapadera monga zochitika zapamtunda, ntchito ya ionic, kukhazikika kwa thovu ndi zowonjezera.
gel zochita. Chifukwa cha zinthuzi, ma cellulose ethers amagwiritsidwa ntchito mu nsalu, kupanga mapepala, zotsukira zopangira, zodzola, chakudya, mankhwala,
Amagwiritsidwa ntchito kwambiri m'madera ambiri.
1.3 Chiyambi chobzala zida zopangira
Kuchokera pakuwunika kwa 1.2 cellulose ether, zitha kuwoneka kuti zopangira zopangira mapadi a cellulose makamaka thonje mapadi, ndi chimodzi mwazomwe zili pamutuwu.
Ndi kugwiritsa ntchito cellulose yotengedwa muzopangira zopangira m'malo mwa thonje ya thonje kuti akonze cellulose ether. Zotsatirazi ndizofotokozera mwachidule za zomera
zakuthupi.
Pamene zinthu zomwe zimagwiritsidwa ntchito monga mafuta, malasha ndi gasi zikuchepa, chitukuko cha zinthu zosiyanasiyana zochokera pa iwo, monga ulusi wopangira ndi mafilimu a fiber, zidzakhalanso zoletsedwa. Ndi chitukuko chosalekeza cha anthu ndi mayiko padziko lonse lapansi (makamaka
Ndi dziko lotukuka) amene amasamalira kwambiri vuto la kuipitsidwa kwa chilengedwe. Ma cellulose achilengedwe ali ndi biodegradability komanso kugwirizanitsa chilengedwe.
Pang'onopang'ono idzakhala gwero lalikulu la zinthu za fiber.
Nthawi yotumiza: Sep-26-2022