IHydroxypropyl Methyl Cellulose Ether Technology

IHydroxypropyl methyl cellulose ether iwuhlobo lwe-nonpolar cellulose ether encibilika emanzini abandayo atholakala ku-cellulose yemvelo ngokwenziwa kwe-alkalization nokuguqulwa kwe-etherification.

Amagama angukhiye:i-hydroxypropyl methylcellulose ether; ukusabela kwe-alkalization; ukusabela kwe-etherification

1. Ubuchwepheshe

I-cellulose yemvelo ayincibiliki emanzini nasezincibilikisini eziphilayo, izinzile ekukhanyeni, ekushiseni, e-asidi, kasawoti kanye neminye imithombo yamakhemikhali yamakhemikhali, futhi ingaswakanyiswa ngesisombululo se-alkali esincibilikayo ukuze sishintshe ingaphezulu leselulosi.

IHydroxypropyl methyl cellulose ether iwuhlobo lwe-ether engeyona i-polar, encibilika emanzini abandayo etholakala ku-cellulose yemvelo ngokusebenzisa i-alkalization nokuguqulwa kwe-etherification.

2. Ifomula eyinhloko yokusabela kwamakhemikhali

2.1 Ukusabela kwe-alkalization

Kunamathuba amabili okusabela kwe-cellulose ne-sodium hydroxide, okungukuthi, ngokwemibandela ehlukene ukukhiqiza ama-molecular compounds, R - OH - NaOH; noma ukukhiqiza izinhlanganisela zotshwala zensimbi, R – ONa.

Izazi eziningi zikholelwa ukuthi i-cellulose isabela ne-alkali egxilile ukuze yakhe into engashintshi, futhi icabanga ukuthi iqembu ngalinye noma amabili e-glucose ahlanganiswe ne-molecule ye-NaOH (iqembu elilodwa le-glucose lihlanganiswe nama-molecule amathathu e-NaOH lapho ukusabela sekuphelile).

C6H10O5 + NaOH→I-C6H10O5 NaOH noma i-C6H10O5 + NaOH→C6H10O4 ONa + H2O

C6H10O5 + NaOH→(C6H10O5 ) 2 NaOH noma i-C6H10O5 + NaOH→C6H10O5 C6H10O4 ONa + H2O

Muva nje, ezinye izazi zikholelwa ukuthi ukusebenzisana phakathi kwe-cellulose ne-alkali egxilile kuzoba nemiphumela emibili ngesikhathi esisodwa.

Ngaphandle kwesakhiwo, umsebenzi wamakhemikhali we-cellulose ungashintshwa ngemva kwesenzo se-cellulose ne-alkali, futhi ingasabela ngemidiya yamakhemikhali ehlukahlukene ukuze ithole izinhlobo ezinengqondo.

2.2 Ukusabela kwe-Etherification

Ngemuva kwe-alkalization, i-alkali cellulose esebenzayo ihlangana ne-etherification agent yakhe i-cellulose ether. Ama-etherifying agents asetshenziswayo yi-methyl chloride ne-propylene oxide.

I-sodium hydroxide isebenza njenge-catalyst.

I-n kanye ne-m imelela izinga lokushintshwa kwe-hydroxypropyl ne-methyl kuyunithi ye-cellulose, ngokulandelanayo. Isamba esiphezulu esingu-m + n singu-3.

Ngaphezu kokusabela okuyinhloko okushiwo ngenhla, kukhona futhi ukusabela okuseceleni:

CH2CH2OCH3 + H2O→HOCH2CH2OHCH3

CH3Cl + NaOH→CH3OH + NaCl

3. Incazelo yenqubo ye-hydroxypropyl methylcellulose ether

Inqubo ye-hydroxypropyl methyl cellulose ether ("i-cellulose ether" ngamafuphi) cishe yakhiwa izinqubo ezi-6, okungukuthi: ukuchotshozwa kwempahla eluhlaza, (i-alkalinization) i-etherification, ukususwa kwe-solvent, ukucwenga nokomisa, ukuchotshozwa nokuxutshwa, kanye nokupakishwa komkhiqizo ophelile.

3.1 Ukulungiselela impahla eluhlaza

I-cellulose yemvelo ye-short-lint ethengiwe emakethe igaywa ibe yimpushana nge-pulverizer ukuze kube lula ukucubungula okulandelayo; i-alkali eqinile (noma i-alkali ewuketshezi) iyancibilika futhi ilungiswe, futhi ishisiswe ibe ngu-90°C ukwenza isixazululo esingu-50% se-caustic soda ukuze sisetshenziswe. Lungiselela ukusabela kwe-methyl chloride, i-ejenti ye-propylene oxide etherification, isopropanol ne-toluene reaction solvent ngesikhathi esifanayo.

Ngaphezu kwalokho, inqubo yokusabela idinga izinto ezisizayo ezifana namanzi ashisayo namanzi ahlanzekile; umusi, amanzi okupholisa izinga lokushisa eliphansi, namanzi okupholisa ajikelezayo kuyadingeka ukusiza amandla.

Ama-linter amafushane, i-methyl chloride, nama-ejenti e-propylene oxide etherification yizinto eziyinhloko zokukhiqiza i-cellulose e-etherified, futhi ama-linter amafushane asetshenziswa ngenani elikhulu. I-Methyl chloride ne-propylene oxide ibamba iqhaza ekuphenduleni njengama-etherification agents ukuze kulungiswe i-cellulose yemvelo, inani lokusetshenziswa alilikhulu.

Ama-solvents (noma ama-diluents) ikakhulukazi ahlanganisa i-toluene ne-isopropanol, okungasetshenzisiwe, kodwa ngenxa yokulahlekelwa okuhlanganisiwe nokuguquguqukayo, kunokulahlekelwa okuncane ekukhiqizeni, futhi inani elisetshenzisiwe lincane kakhulu.

Inqubo yokulungiselela impahla eluhlaza inendawo yethangi lempahla eluhlaza kanye nendawo yokugcina impahla eluhlaza enamathiselwe. I-Etherifying agents nezinyibilikisi, njenge-toluene, isopropanol, ne-acetic acid (esetshenziselwa ukulungisa inani le-pH lama-reactants), kugcinwa endaweni yethangi lempahla eluhlaza. Ukunikezwa kwe-lint emfushane kwanele , kunganikezwa yimakethe nganoma yisiphi isikhathi.

I-lint emfushane echotshoziwe ithunyelwa endaweni yokusebenzela nekalishi ukuze isetshenziswe.

3.2 (I-Alkalinization) i-etherification

I-etherification (i-alkaline) iyinqubo ebalulekile enqubweni ye-etherification ye-cellulose. Endleleni yokukhiqiza yangaphambili, ukusabela okuyizinyathelo ezimbili kwenziwa ngokuhlukana. Manje inqubo isithuthukisiwe, futhi ukusabela kwezinyathelo ezimbili kuhlanganiswa esigabeni esisodwa futhi kwenziwa kanyekanye.

Okokuqala, vacuza ithangi le-etherification ukuze ukhiphe umoya, bese ufaka i-nitrogen esikhundleni salo ukuze ithangi lingabi namoya. Engeza isisombululo se-sodium hydroxide esilungisiwe, engeza inani elithile le-isopropanol ne-toluene solvent, qala ukugqugquzela, bese ufaka uvolo wekotini omfushane, uvule amanzi ajikelezayo ukuze aphole, futhi ngemva kokuba izinga lokushisa lehla liye ezingeni elithile, vula i-low-. amanzi okushisa ukuze unciphise izinga lokushisa lempahla yesistimu Yehla ifike cishe ku-20℃, futhi ugcine ukusabela isikhathi esithile ukuze uqedele i-alkalization.

Ngemuva kwe-alkalization, engeza i-etherifying agent i-methyl chloride ne-propylene oxide elinganiswa ithangi lemitha lezinga eliphezulu, qhubeka uqale ukunyakazisa, sebenzisa isitimu ukuze ukhuphule izinga lokushisa lesistimu lifinyelele cishe ku-70.℃~ 80℃, bese usebenzisa amanzi ashisayo ukuze uqhubeke nokushisa nokugcina Izinga lokushisa lokusabela liyalawulwa, bese izinga lokushisa lokusabela kanye nesikhathi sokuphendula kulawulwa, futhi ukusebenza kungaqedwa ngokugqugquzela nokuxuba isikhathi esithile.

Ukusabela kwenziwa cishe ngama-90°C kanye ne-0.3 MPa.

3.3 Ukuchithwa

Izinto ezibalulwe ngenhla zenqubo zithunyelwa ku-desolventizer, futhi izinto zokwakha ziyakhunyulwa futhi zishiswe ngesitimu, futhi i-toluene ne-isopropanol solvents iyahwamuka futhi ibuyiselwe ukuze igaywe kabusha.

I-solvent e-evaporated iqala ipholile futhi ihlanganiswe kancane ngamanzi ajikelezayo, bese ihlanganiswa ngamanzi aphansi okushisa, futhi ingxube ye-condensate ingena ungqimba lwe-liquid kanye nesihlukanisi ukuhlukanisa amanzi ne-solvent. I-solvent exubile ye-toluene ne-isopropanol kungqimba engaphezulu ilungiswa ngokulingana. Yisebenzise ngokuqondile, bese ubuyisela amanzi nesisombululo se-isopropanol kungqimba engezansi ku-desolventizer ukuze uyisebenzise.

Engeza i-acetic acid ku-reactant ngemva kokuncibilika ukuze unciphise i-sodium hydroxide eyengeziwe, bese usebenzisa amanzi ashisayo ukugeza okokusebenza, usebenzise ngokugcwele isici sokujiya se-cellulose ether emanzini ashisayo ukuze ugeze i-cellulose ether, futhi ucwenge i-reactant. Izinto ezicolisisiwe zithunyelwa enqubweni elandelayo yokuhlukaniswa nokomiswa.

3.4 Hlunga futhi womise

Into ecolisisiwe ithunyelwa kusihlukanisi sesikulufu esivundlile ngephampu yesikulufu sokucindezela okuphezulu ukuze kuhlukanise amanzi amahhala, futhi into eqinile esele ingena endaweni yokomisa umoya ngesiphakeli esiyisikulufu, bese yomiswa lapho ithintana nomoya oshisayo, bese idlula isishingishane. isihlukanisi nomoya Ukuhlukaniswa, izinto eziqinile zingena ekuchosheni okulandelayo.

Amanzi ahlukaniswe yisihlukanisi esivundlile esivundlile angena ethangini lokuhlanza amanzi ngemva kokucwiliswa kwenhlabathi ethangini le-sedimentation ukuze ahlukanise i-cellulose ehlanganisiwe.

3.5 Ukuchoboza nokuxuba

Ngemva kokumiswa, i-cellulose e-etherified izoba nosayizi wezinhlayiyana ezingalingani, okudingeka zichotshozwe futhi zixutshwe ukuze ukusabalalisa usayizi wezinhlayiyana kanye nokubukeka okuphelele kwezinto kuhlangabezane nezidingo ezijwayelekile zomkhiqizo.

3. 6 Kuqediwe ukupakishwa komkhiqizo

Izinto ezitholakala ngemva kokuchotshozwa nokuxuba imisebenzi yi-cellulose e-etherified eqediwe, engapakishwa futhi ibekwe endaweni yokugcina.

4. Isifinyezo

Amanzi angcolile ahlukanisiwe aqukethe inani elithile likasawoti, ikakhulukazi i-sodium chloride. Amanzi angcolile ayahwamuka ukuze ahlukanise usawoti, futhi isitimu sesibili esihwamukile singafingqwa ukuze kubuyiselwe amanzi ajiyile, noma akhishwe ngokuqondile. Ingxenye eyinhloko kasawoti ohlukanisiwe i-sodium chloride, equkethe nenani elithile le-acetate ye-sodium ngenxa yokungathathi hlangothi nge-acetic acid. Lo sawoti unenani lokusetshenziswa kwezimboni kuphela ngemuva kokuvuselelwa kabusha, ukuhlukaniswa nokuhlanzwa.