Focus on Cellulose ethers

Yintoni inkqubo yokwenziwa kweCellulose ether?

Umgaqo-nkqubo wokusabela we-cellulose ether hydroxypropyl methyl cellulose: ukuveliswa kwe-HPMC i-hydroxypropyl methyl cellulose isebenzisa i-methyl chloride kunye ne-propylene oxide njenge-etherification agents. I-equation ye-chemical reaction equation yile: I-Rcell-OH (umqhaphu ococekileyo) + NaOH (i-sodium hydroxide), i-Sodium hydroxide) + i-CspanCl (i-methyl chloride) + CH2OCHCspan (propylene oxide) → i-Rcell-O -CH2OHCHCspan (hydroxypropyl methylcellulose) + NaCl (sodium chloride) ) + H2O (amanzi)

Inkqubo yokuhamba:

esulungekileyo umqhaphu ukutyunyuzwa-alkalization-ukutya-alkalization-etherification-solvent recovery kunye nokuhlamba-centrifugal ukwahlula-zomisa-ukutyumza-ukuxuba -Imveliso ukupakishwa

I-1: Izinto eziphathekayo kunye nezinto ezincedisayo zokuvelisa i-hydroxypropyl methylcellulose Eyona nto iphambili i-cotton ecocekileyo, kunye nezinto ezincedisayo ziyi-sodium hydroxide (i-sodium hydroxide), i-propylene oxide, i-methyl chloride, i-acetic acid, i-toluene, isopropanol, kunye ne-nitrogen. Injongo yokucolwa komqhaphu esulungekileyo kukutshabalalisa ulwakhiwo oludityanisiweyo lwekotoni esulungekileyo ngokusebenzisa amandla omatshini ukunciphisa i-crystallinity kunye ne-polymerization degree kunye nokwandisa indawo yayo.

I-2: Umlinganiselo kunye nokulawulwa kwekhwalithi yezinto eziluhlaza: Ngaphantsi kwesiseko sezixhobo ezithile, umgangatho wayo nayiphi na into ephambili kunye neyokuncedisayo kunye nomlinganiselo wexabiso elongezelelweyo kunye nokuxinana kwe-solvent kuchaphazela ngokuthe ngqo izibonakaliso ezahlukeneyo zemveliso. Inkqubo yenkqubo yokuvelisa iqulethe umlinganiselo othile wamanzi, kwaye amanzi kunye ne-solvents ye-organic ayixubeki ngokupheleleyo, kwaye ukusasazwa kwamanzi kuchaphazela ukuhanjiswa kwe-alkali kwinkqubo. Ukuba ayishukunyiswanga ngokwaneleyo, iya kuba yingxaki kwi-alkalization efanayo kunye ne-etherification ye-cellulose.

I-3: Ukuvuselela kunye nokugqithiswa kobuninzi kunye nokutshintshwa kobushushu: I-cellulose alkalization kunye ne-etherification zonke zenziwa phantsi kweemeko ezingafaniyo (ukuvuselela amandla angaphandle). Ingaba ukusabalalisa kunye nokudibanisa kwamanzi, i-alkali, i-cotton ecocekileyo kunye ne-etherifying agent kwinkqubo ye-solvent iyalingana ngokwaneleyo, iya kuchaphazela ngokuthe ngqo i-alkalization kunye nemiphumo ye-etherification. Ukuphazamiseka okungafaniyo ngexesha lenkqubo ye-alkalization kuya kubangela iikristale ze-alkali kunye nemvula ephantsi kwesixhobo. I-concentration yomgangatho ophezulu iphantsi kwaye i-alkalization ayanelanga. Ngenxa yoko, kusekho isixa esikhulu sealkali yasimahla kwinkqubo emva kokuba i-etherification igqityiwe. Ukufana, okukhokelela ekuhleni okulambathayo, iintsinga ezisimahla, ukugcinwa kwamanzi okulambathayo, indawo yejeli ephantsi, kunye nexabiso eliphezulu le-PH.

4: Inkqubo yokuvelisa (inkqubo yokuvelisa uludaka)

(1:) Yongeza inani elichaziweyo lealkali eqinileyo (790Kg) kunye namanzi (inkqubo iyonke yamanzi 460Kg) kwiketile yesoda ye-caustic, ushukume kunye nobushushu kubushushu obungaguqukiyo obungama-80 degrees ngaphezulu kwemizuzu engama-40, kunye nealkali eyomeleleyo ngokupheleleyo. inyibilikiswe.

(2:) Yongeza i-6500Kg ye-solvent kwi-reactor (umlinganiselo we-isopropanol kwi-toluene kwi-solvent malunga ne-15/85); cofa ialkali kwireactor, kwaye utshize i200Kg yesinyibilikisi kwitanki yealkali emva kokucinezela ialkali. Gubha umbhobho; iketile yokusabela ipholile ukuya kuma-23°C, kwaye umqhaphu ocoliweyo ocoliweyo (800Kg) wongezwa. Emva kokuba umqhaphu osulungekisiweyo wongeziwe, i-600Kg ye-solvent iyatshizwa ukuqala ukusabela kwe-alkalization. Ukongezwa komqhaphu ocoliweyo ocoliweyo kufuneka kugqitywe ngexesha elichaziweyo (imizuzu eyi-7) (ubude bexesha elongezelelweyo libaluleke kakhulu). Emva kokuba umqhaphu ococekileyo udibana nesisombululo se-alkali, i-alkalization reaction reaction iqala. Ukuba ixesha lokutya lide kakhulu, iqondo le-alkalization liya kuhluka ngenxa yexesha apho ikotoni ecocekileyo ingena kwinkqubo yokusabela, okubangela ukungalingani kwe-alkalization kunye nokunciphisa ukufana kwemveliso. Ngelo xesha, kuya kubangela ukuba i-cellulose ye-alkali idibane nomoya ixesha elide i-oxidize kunye nokunciphisa, okubangelwa ukuba i-viscosity yemveliso iyancipha. Ukuze ufumane iimveliso ezinamazinga ahlukeneyo e-viscosity, i-vacuum kunye ne-nitrogen ingasetyenziswa ngexesha lenkqubo ye-alkalization, okanye inani elithile le-antioxidant (dichloromethane) lingafakwa. Ixesha le-alkalization lilawulwa kwi-120min, kwaye izinga lokushisa ligcinwa kwi-20-23 ℃.

(3:) Emva kokuba i-alkalization iphelile, yongeza inani elichaziweyo le-etherifying agent (methyl chloride kunye nepropylene oxide), phakamisa ubushushu kwiqondo lokushisa elichaziweyo kwaye uqhube ukusabela kwe-etherification ngaphakathi kwexesha elichaziweyo.

Iimeko ze-Etherification: 950Kg ye-methyl chloride kunye ne-303Kg ye-propylene oxide. Yongeza i-etherification agent kwaye upholile kwaye uvuselele imizuzu engama-40 kwaye unyuse ubushushu. Iqondo lobushushu lokuqala le-etherification liyi-56°C, ixesha lobushushu elingaguqukiyo yi-2.5h, elesibini i-etherification liyi-87°C, kwaye iqondo lobushushu elingaguqukiyo yi-2.5h. Ukusabela kwe-hydroxypropyl kunokuqhubeka malunga ne-30 ° C, izinga lokuphendula likhawuleza kakhulu kwi-50 ° C, i-methoxylation reaction iyancipha kwi-60 ° C, kwaye iyancipha ngaphantsi kwe-50 ° C. Ubungakanani, umlinganiselo kunye nexesha le-methyl chloride kunye nepropylene oxide, kunye nokulawulwa kokunyuka kweqondo lokushisa kwenkqubo ye-etherification, ichaphazela ngqo isakhiwo semveliso.

Izixhobo eziphambili zokuvelisa i-HPMC yi-reactor, i-dryer, i-granulator, i-pulverizer, njl njl. Okwangoku, abavelisi abaninzi bangaphandle basebenzisa izixhobo eziveliswa eJamani. Izixhobo eziveliswe ekhaya, nokuba sisikhundla semveliso okanye umgangatho wokuvelisa, azikwazi ukuhlangabezana neemfuno zomgangatho ophezulu wemveliso ye-HPMC.

I-All-In-One Reactor eveliswe eJamani inokugqiba amanyathelo enkqubo amaninzi ngesixhobo esinye, iqonde ulawulo oluzenzekelayo, umgangatho wemveliso ozinzile, kunye nokusebenza okukhuselekileyo nokuthembekileyo kwemveliso.

Izinto eziphambili zokwenziwa kwe-HPMC yikotoni esulungekileyo, i-sodium hydroxide, i-methyl chloride, kunye ne-propylene oxide.


Ixesha lokuposa: Nov-11-2021
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