Focus on Cellulose ethers

Kodi kupanga ma cellulose ether ndi chiyani?

Mfundo ya cellulose ether hydroxypropyl methyl cellulose: kupanga HPMC hydroxypropyl methyl cellulose amagwiritsa ntchito methyl chloride ndi propylene oxide ngati etherification agents.The chemical reaction equation ndi: Rcell-OH (thonje woyengedwa) + NaOH (sodium hydroxide), Sodium hydroxide) + CspanCl (methyl chloride) + CH2OCHCspan (propylene oxide) → Rcell-O -CH2OHCHCspan (hydroxypropyl methylcellulose) + NaCl (sodium chloride) + H2O (madzi)

Njira yoyenda:

woyengedwa thonje kuphwanya-alkalization-kudyetsa-alkalization-etherification-zisungunulira kuchira ndi kutsuka-centrifugal kulekana-kuyanika-kuphwanya-kusakaniza-kusakaniza-Kupaka katundu

1: Zopangira ndi zida zothandizira kupanga hydroxypropyl methylcellulose Zopangira zazikulu ndi thonje woyengedwa, ndipo zida zothandizira ndi sodium hydroxide (sodium hydroxide), propylene oxide, methyl chloride, acetic acid, toluene, isopropanol, ndi nayitrogeni.Cholinga cha woyengedwa thonje kuphwanya ndi kuwononga aggregated dongosolo la thonje woyengedwa kudzera mawotchi mphamvu kuchepetsa crystallinity ndi polymerization digiri ndi kuonjezera pamwamba dera.

2: Kuyeza ndi kuwongolera kwazinthu zopangira: Pansi pazida zina, mtundu wa zida zilizonse zazikulu ndi zothandizira komanso kuchuluka kwa kuchuluka kwake komanso kuchuluka kwa zosungunulira kumakhudza mwachindunji zisonyezo zosiyanasiyana za chinthucho.Dongosolo la kupanga lili ndi madzi ena, ndipo madzi ndi zosungunulira za organic sizimasokonezana, ndipo kubalalitsidwa kwa madzi kumakhudza kugawa kwa alkali mu dongosolo.Ngati sichikugwedezeka mokwanira, zidzakhala zovuta kuti yunifolomu alkalization ndi etherification ya cellulose.

3: Kulimbikitsana ndi kusuntha kwa misa ndi kutengera kutentha: Ma cellulose alkalization ndi etherification zonse zimachitika mosiyanasiyana (kuyambitsa mphamvu yakunja).Kaya kubalalitsidwa ndi kukhudzana kwa madzi, alkali, thonje woyengedwa ndi etherifying wothandizila mu zosungunulira dongosolo mokwanira yunifolomu, zimakhudza mwachindunji alkalization ndi etherification zotsatira.Kusokoneza mosagwirizana panthawi ya alkalization kumayambitsa makristasi amchere ndi mpweya pansi pazida.Chapamwamba wosanjikiza ndende ndi otsika ndi alkalization sikokwanira.Chotsatira chake, pamakhalabe kuchuluka kwa alkali yaulere mu dongosolo pambuyo pa etherification.Kufanana, zomwe zimapangitsa kuti pakhale kusawonekera bwino, ulusi waulere wambiri, kusasunga bwino kwa madzi, gel otsika, komanso PH mtengo.

4: Njira yopanga (njira yopanga slurry)

(1 :) Onjezani kuchuluka kwapadera kwa alkali olimba (790Kg) ndi madzi (okwana dongosolo madzi 460Kg) mu caustic koloko ketulo, chipwirikiti ndi kutentha kwa kutentha zonse madigiri 80 kwa mphindi zoposa 40, ndi alkali olimba kwathunthu. kusungunuka.

(2:) Add 6500Kg zosungunulira kwa riyakitala (chiŵerengero cha isopropanol toluene mu zosungunulira ndi za 15/85);kanikizani alkali mu riyakitala, ndi kupopera 200Kg zosungunulira ku thanki ya alkali mutakanikiza alkaliyo.Chotsani payipi;ketulo anachita utakhazikika kwa 23 ° C, ndi pulverized woyengeka thonje (800Kg) anawonjezera.Pambuyo pakuwonjezedwa kwa thonje woyengedwa, 600Kg ya zosungunulira imapopera kuti ayambe kuchitapo kanthu.Kuwonjezera kwa thonje woyengedwa wosweka kuyenera kumalizidwa mkati mwa nthawi yotchulidwa (7 mphindi) (kutalika kwa nthawi yowonjezera ndikofunika kwambiri).Kamodzi thonje woyengedwa akumana ndi yankho la alkali, zochita za alkalization zimayamba.Ngati nthawi yodyetsa ndi yaitali kwambiri, mlingo wa alkalization adzakhala osiyana chifukwa cha nthawi imene thonje woyengedwa akulowa anachita dongosolo, chifukwa m'malo alkalization ndi kuchepetsedwa mankhwala mofanana.Panthawi imodzimodziyo, zidzachititsa kuti cellulose ya alkali ikhale yogwirizana ndi mpweya kwa nthawi yaitali kuti iwonongeke komanso iwonongeke, zomwe zimapangitsa kuti kukhuthala kwa mankhwalawa kumachepa.Kuti mupeze mankhwala okhala ndi milingo yosiyanasiyana ya viscosity, vacuum ndi nayitrogeni zitha kugwiritsidwa ntchito panthawi ya alkalization, kapena kuchuluka kwa antioxidant (dichloromethane) kumatha kuwonjezeredwa.Nthawi ya alkalization imayendetsedwa pa 120min, ndipo kutentha kumasungidwa pa 20-23 ℃.

(3 :) Pambuyo pa alkalization, onjezerani kuchuluka kwa etherifying wothandizira (methyl chloride ndi propylene oxide), kwezani kutentha kwa kutentha kwapadera ndikuchita etherification mu nthawi yotchulidwa.

Etherification zinthu: 950Kg wa methyl kolorayidi ndi 303Kg wa propylene okusayidi.Onjezani etherification wothandizira ndikuziziritsa ndikuyambitsa kwa mphindi 40 ndikukweza kutentha.Kutentha koyamba kwa etherification ndi 56 ° C, nthawi yotentha yokhazikika ndi 2.5h, kutentha kwachiwiri kwa etherification ndi 87 ° C, ndi kutentha kosalekeza ndi 2.5h.Hydroxypropyl reaction imatha kupitilira pafupifupi 30 ° C, kuchuluka kwa zomwe zimachitika kumachulukira kwambiri pa 50 ° C, momwe methoxylation imayendera pang'onopang'ono pa 60 ° C, ndipo imachepera 50 ° C.Kuchuluka, kuchuluka ndi nthawi ya methyl chloride ndi propylene oxide, komanso kuwongolera kutentha kwa njira ya etherification, zimakhudza mwachindunji kapangidwe kazinthu.

Zida zazikulu zopangira HPMC ndi reactor, dryer, granulator, pulverizer, etc. Pakalipano, opanga ambiri akunja amagwiritsa ntchito zipangizo zopangidwa ku Germany.Zida zopangidwa kunyumba, kaya ndi mphamvu zopangira kapena kupanga, sizingakwaniritse zosowa zamtundu wapamwamba wa HPMC.

All-In-One Reactor yopangidwa ku Germany imatha kumaliza masitepe angapo ndi chipangizo chimodzi, kuzindikira kudziwongolera, kukhazikika kwazinthu, komanso kupanga kotetezeka komanso kodalirika.

Zida zazikulu zopangira HPMC ndi thonje woyengedwa, sodium hydroxide, methyl chloride, ndi propylene oxide.


Nthawi yotumiza: Nov-11-2021
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