Focus on Cellulose ethers

Kodi hydroxypropylcellulose imapangidwa bwanji?

Hydroxypropylcellulose (HEC) ndi chochokera ku cellulose, polima wachilengedwe wopezeka m'makoma a cellulose.HPC imagwiritsidwa ntchito kwambiri m'mafakitale osiyanasiyana monga opanga mankhwala, zodzoladzola ndi mafakitale azakudya chifukwa cha mawonekedwe ake abwino kwambiri opangira mafilimu komanso kukhuthala.The synthesis wa hydroxypropylcellulose kumafuna angapo masitepe ndi ndondomeko kungakhale kovuta.

Chiyambi cha hydroxypropylcellulose:

1. Kugwiritsa ntchito cellulose poyambira:

Magwero akuluakulu a cellulose ndi zinthu zakubzala monga zamkati zamatabwa kapena thonje.Ma cellulose ndi mzere wa polima wopangidwa ndi mayunitsi a shuga olumikizidwa ndi β-1,4-glycosidic bond.Ili ndi kuchuluka kwa polymerization, yokhala ndi mayunitsi masauzande a glucose omwe amapanga unyolo wautali.

2. Etherification reaction:

Kaphatikizidwe ka hydroxypropylcellulose kumaphatikizapo kuyambitsa magulu a hydroxypropyl mu cellulose backbone kudzera etherification.Izi zimaphatikizapo kugwiritsa ntchito propylene oxide ngati alkylating agent.

Cellulose + propylene oxide → alkali-catalyzed hydroxypropyl cellulose + by-product cellulose + propylene oxide alkali-catalyzed hydroxypropyl cellulose + by-product

Base catalysis ndiyofunikira kulimbikitsa zomwe zimachitika pakati pamagulu a cellulose hydroxyl ndi propylene oxide.Izi nthawi zambiri zimachitika molamulidwa kuti zitsimikizire kuchuluka komwe kumafunikira (DS) kwamagulu a hydroxypropyl pa unyolo wa cellulose.

3. Hydroxypropylation:

Hydroxypropylation imaphatikizapo kuwonjezera magulu a hydroxypropyl ku msana wa cellulose.Kusintha kumeneku kumapereka kusungunuka kwabwino ndi zinthu zina zofunika ku cellulosic polima.Zomwe zimachitika, kuphatikiza kutentha, kupanikizika ndi nthawi yochitira, zimayendetsedwa bwino kuti zikwaniritse zomwe mukufuna.

4. Chithandizo cha alkali:

Pambuyo pa hydroxypropylation, mankhwala amchere nthawi zambiri amagwiritsidwa ntchito kuti achepetse zonyansa zilizonse zotsalira za acidic ndikusintha pH ya zomwe osakaniza.Njira imeneyi ndi yofunika kwambiri pa ntchito yoyeretsera.

5. Njira zoyeretsera:

Pambuyo pa etherification, njira zingapo zoyeretsera nthawi zambiri zimachitidwa kuti apeze hydroxypropylcellulose yapamwamba kwambiri.Izi zingaphatikizepo:

Sambani: Sambani zomwe zimasakanikirana kuti muchotse zotsalira zotsalira, zotsalira ndi mapadi osakhudzidwa.

Sefa: Kusefera kumagwiritsidwa ntchito kulekanitsa zodetsa zolimba ndi zomwe zimasakanikirana.

Kuyanika: Ma cellulose onyowa a hydroxypropyl amawumitsidwa kuti achotse chinyezi chilichonse.

6. Kuwongolera kulemera kwa maselo:

The molecular kulemera kwa hydroxypropylcellulose akhoza lizilamuliridwa pa kaphatikizidwe kuti zigwirizane ndi katundu wake kuti ntchito yeniyeni.Izi zimatheka ndi kusintha anachita zinthu, monga kuchuluka kwa reagents ndi anachita nthawi.

Kupanga mafakitale:

1. Njira yapakatikati kapena yopitilira:

Kupanga kwa cellulose ya hydroxypropyl kumatha kuchitika mumtanda kapena mosalekeza.Njira ya batch ndiyoyenera kupanga pang'ono, pomwe njira yopitilira ndiyoyenera kupanga zazikulu.

2. Kuwongolera khalidwe:

Njira zowongolera zabwino zimayendetsedwa pazigawo zonse zakupanga kuti zitsimikizire kusasinthika komanso kuyera kwa chinthu chomaliza.Njira zowunikira monga chromatography, spectroscopy ndi maphunziro a rheological amagwiritsidwa ntchito poyesa magawo ofunikira monga kuchuluka kwa m'malo, kulemera kwa maselo ndi chiyero.

Ntchito ya Hydroxypropyl Cellulose:

1. Makampani opanga mankhwala:

Hydroxypropylcellulose amagwiritsidwa ntchito kwambiri pokonzekera mankhwala monga binder, disintegrant and controlled release agent.Kugwirizana kwake ndi mitundu yosiyanasiyana ya mankhwala ndi kusakhazikika kwake kumapangitsa kuti ikhale yothandiza mosiyanasiyana.

2. Makampani opanga zodzoladzola:

M'makampani opanga zodzoladzola, hydroxypropylcellulose imagwiritsidwa ntchito popanga zinthu zosamalira tsitsi, zopaka pakhungu ndi zinthu zina zosamalira anthu.Mawonekedwe ake opanga mafilimu amapangitsa kuti ikhale yamtengo wapatali muzinthu zosamalira tsitsi.

3. Makampani azakudya:

M'makampani azakudya, hydroxypropylcellulose imagwiritsidwa ntchito ngati thickener ndi gelling agent.Zimapezeka muzakudya zosiyanasiyana ndipo zimathandiza kukonza kamangidwe kake ndi kukhazikika.

Kaphatikizidwe ka hydroxypropylcellulose kumaphatikizapo etherification ya cellulose powonjezera magulu a hydroxypropyl.Zomwe zimachitika nthawi zambiri zimayendetsedwa ndi maziko, ndikutsatiridwa ndi njira zoyeretsera kuti mupeze chinthu choyera kwambiri.Kupanga mafakitale kumatha kuchitidwa ndi batch kapena njira zopitilira ndi njira zowongolera bwino.Hydroxypropylcellulose ili ndi ntchito zambiri m'makampani opanga mankhwala, zodzoladzola ndi zakudya chifukwa chapadera komanso kusinthasintha kwake.Kuwongolera kosalekeza kwa njira zopangira komanso kupanga mapulogalamu atsopano kumatsindika


Nthawi yotumiza: Dec-26-2023
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