1.Ukuhlela kanye nokulungiselela umgomo we-cellulose ether
Umdwebo 1 ukhombisa ukwakheka okujwayelekile kwe-cellulose afes. I-BD-Anhydroglucose ngayinye (iyunithi ephindaphindwayo ye-cellulose) ithatha indawo yeqembu elilodwa ku-C (2 (3) kanye nezikhundla ze-C (6), okungukuthi, kungaba khona amaqembu afinyelela amathathu. Ngenxa ye-intra-chain kanye nama-hydrogen ama-hydrogen ama-hydrogenama-cellulose macromelecule, kunzima ukuncibilikisa emanzini futhi cishe wonke ama-solvents aphilayo. Ukwethulwa kwamaqembu e-ether ngokusebenzisa ukusheshisa kubhubhisa ama-hydrogen ama-hydrogen
Ukufakwa esikhundleni okujwayelekile okuthe xaxa kungama-alkoxy aphansi ama-alkoxy amaqembu aphansi (1 kuya ku-4 ama-atoms wekhabhoni) noma amaqembu we-hydroxyalkyl, angahle afakwe esikhundleni samanye amaqembu asebenzayo anjengezinhlelo ze-carboxyl, ama-hydroxyl noma ama-amino. Ukufakazela kungahle kube munye, izinhlobo ezimbili noma ngaphezulu ezahlukahlukene. Ngasekupheleni kwe-cellulose macromolecular chain, amaqembu we-hydroxyl ku-C (2), C (3) kanye nezikhundla ze-glucose ngayinye zifakwa esikhundleni sezilinganiso ezihlukile. Ukukhuluma ngokuqinile, imvamisa i-ether ayinalo isakhiwo samakhemikhali aqondile, ngaphandle kwaleyo mikhiqizo etholakala esikhundleni sohlobo olulodwa lweqembu (wonke amaqembu amathathu e-hydroxyl afakwa esikhundleni). Le mikhiqizo ingasetshenziswa kuphela ukuhlaziya kwelebhu kanye nocwaningo, futhi ayinalo inani lezentengiso.
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(b) Ucezu lwama-molecular chain for motobyboxylylIHydroxYethyl Cellulose, izinga lokufaka esikhundleni se-carboxymetyl lingu-0,5, izinga lokufaka esikhundleni se-hydroxyethyl lingu-2.0, kanye nezinga lokufaka esikhundleni se-molar kungu-3.0. Lesi sakhiwo simele isilinganiso sokufakwa esikhundleni samaqembu anetherified, kepha ukufakwa esikhundleni empeleni kuyinto engahleliwe.
Ngokubanjwa ngakunye, inani eliphelele lokuthezeka livezwa ngezinga lenani le-DS elifakiwe. Uhla lwe-DS ngu-0 ~ 3, olulingana nenombolo ephakathi yamaqembu ama-hydroxyl afakwe esikhundleni ngamaqembu okuthepha kuyunithi yokungena kwe-anhydroglucose.
Okwe-Hydroxyalkyl cellulose izitha, ukusabela kokufakwa esikhundleni kuzoqala ukusheshisa kusuka kumaqembu amasha we-hydroxyl, futhi izinga lokufaka esikhundleni se-MS lingalinganiswa yinani le-MS, okungukuthi, izinga le-molar lokufaka esikhundleni. Imelela inani eliphakathi lama-moles we-ejenti etherali e-agent angezwe kuyunithi ngayinye ye-anhydroglucose. I-reactivance ejwayelekile yi-ethylene oxide futhi umkhiqizo une-hydroxyethyl. Kumfanekiso 1, inani le-MS lomkhiqizo lingu-3.0.
Ngokweqiniso, akukho mkhawulo ophezulu wenani le-MS. Uma inani le-DS le-degree lokufaka esikhundleni seqembu ngalinye le-glucose liyaziwa, ubude obumaphakathi we-chain of the ether eceleni kwamaqembu (i-WT%) yamaqembu ahlukahlukene (i-WT%) yamaqembu ahlukile (i-WOCH3 noma -OCH44OH) ukumela izinga lokufaka kanye namanani we-DS nama-MS. Ingxenyana enkulu yeqembu ngalinye nama-DS noma i-MS Value ingaguqulwa ukubalwa okulula.
Iningi le-cellulose izithathekisa ama-polymers ancibilikayo, kanti amanye ayancibilika ngokwengxenye yezinto eziphikisayo. I-Celsulose Ether inezimpawu zokusebenza kahle, intengo ephansi, ukucubungula okulula, ubuthi obuphansi nezinhlobonhlobo ezahlukahlukene, kanye nezinkundla zokufuna zohlelo lokusebenza zisakhula. Njenge-ejenti elisizayo, i-cellulose ether inamathuba amaningi okusebenza emikhakheni ehlukahlukene yezimboni. ingatholakala nge-MS / DS.
I-Cellulose Afers ihlukaniswa ngokuya ngesakhiwo samakhemikhali sokufakwa esikhundleni kwe-anionic, i-cationic kanye ne-anion. Abathakathi be-Nonionic bangahlukaniswa ngemikhiqizo engenamanzi-encibilike kawoyela.
Imikhiqizo eye yathuthukiswa izimboni ibhalwe engxenyeni engenhla yetafula 1. Ingxenye engezansi yetafula 1 ibala amaqembu athile ashelelayo, awakabi yimikhiqizo ebalulekile yezentengiso.
Ukuhleleka kwesifinyezo kokunye okuhlanganisiwe kwe-Ether
Amaqembu e-hydroxyl e-cellulose atholakala kalula ngama-ejenti athether, futhi inqubo yokuthethelwa ivame ukwenziwa ngaphansi kwezimo ze-alkali, ngokuvamile usebenzisa isisombululo esithile se-naoh esinamanzi. I-cellulose yaqala yakhiwa i-Alkali Cellulose evuvukile ngekhambi le-Naoh, bese ibhekana nokusabela kokuthembela nge-ejenti yokuthembela. Ngesikhathi sokukhiqizwa kanye nokulungiswa kwezithambekele ezixubile, izinhlobo ezahlukene zama-ejenti asheshisi kufanele zisetshenziswe ngasikhathi sinye, noma ukusheshisa kufanele zenziwe ngesinyathelo ngesinyathelo ngesinyathelo ngesinyathelo nge-incmittent feed (uma kunesidingo). Kunezinhlobo ezine zokuphendula ekuthethelweni kwe-cellulose, ezifingqiwe yifomula yokuphendula (i-cellulosic ithathelwe indawo yi-cell-oh) kanjena:
I-Equation (1) ichaza ukusabela kwe-williamson ukusabela. I-RX ingu-inorganic acid ester, futhi u-X yi-halogen br, cl noma sulfuric acid ester. UChloride R-CL uvame ukusetshenziswa embonini, ngokwesibonelo, i-methyl chloride, i-ethyl chloride noma i-chlororoacetic acid. Inani lesisekelo se-Stoichiometric lidliwe ekusameni okunjalo. Imikhiqizo ye-cellulose ether ye-cellulose ether ye-methyl celtule, i-ethyl cellulose kanye ne-carboxymethyl cellulose yimikhiqizo ye-Williamson Etherification Reaction.
Ifomula yokuphendula (2) ukusabela kokungezwa kwe-epoxides eyisisekelo (efana ne-r = h, CH3, noma i-C2H5) namaqembu e-hydroxy kuma-molecule e-cellulose ngaphandle kokudla. Lokhu kusabela kungenzeka kuqhubeke njengoba amaqembu amasha we-hydroxyl akhiqizwa ngesikhathi sokusabela, okuholela ekwakhekeni kwamaketanga amahlaya we-oligoalkyleneleneliyleleni: ukusabela okufanayo nge-1-aziridine (aziridine) kuzokwakha i-Aminoethyl Ether: Cell-O-CH2-CH2-NH2. Imikhiqizo efana ne-hydroxyethyl cellulose, i-hydroxypropyl cellulose kanye ne-hydroxybutyl cellulose kuyo yonke imikhiqizo ye-epoxidation eyisisekelo.
Ifomula yokuphendula (3) ukusabela phakathi kwama-cell-oh kanye nama-organic compound aqukethe amabhondi aphindwe kabili asebenzayo e-Alkaline Medium, y yiqembu elihoxiswa nge-elektroni, njenge-CN, CON2, noma i-SOL3-NA +. Namuhla lolu hlobo lokuphendula alusetshenziswa ngokujwayelekile.
Ifomula yokuphendula (4), ukusheshisa nge-diazoallone akukaze kube yinzuzo okwamanje.
- Izinhlobo ze-cellulose afers
I-Cellulose Ether ingaba yi-ether noma exubile, futhi izakhiwo zayo zihlukile. Kunamaqembu angenamikhawulo e-hydrophilic e-cellulose macromolecule, efana namaqembu we-hydroxyethyl, angawunika umkhiqizo ngezinga elithile le-solubity yamanzi, kanti u-hydrophobic degree anganikezelwa kuphela emanzini noma angachithwa ku-alkali ye-talkali Isixazululo. Ngokucwaninga okujulile ngezakhiwo ze-cellulose afers, izithambiso ezintsha ze-cellulose kanye nezinkundla zazo zohlelo lokusebenza zizothuthukiswa ngokuqhubekayo futhi zikhiqizwe, futhi amandla amakhulu okushayela yimakethe yesicelo ebanzi futhi eqhubekayo.
Umthetho ojwayelekile wethonya lamaqembu ekubumbeni okuxubile nge-solibity Properties yile:
1) Khulisa okuqukethwe kwamaqembu we-hydrophobic kumkhiqizo ukukhulisa i-hydrophopobicity ye-ether bese wehlisa iphuzu le-gel;
2) Khulisa okuqukethwe kwamaqembu we-hydrophilic (njengamaqembu we-hydroxyethyl) ukwandisa iphuzu lawo le-gel;
3) Iqembu le-hydroxypropyl likhethekile, futhi i-hydroxypropylication efanelekile inganciphisa izinga lokushisa le-gel lomkhiqizo, futhi izinga lokushisa le-gel lomkhiqizo ophakathi kwe-hydroxypropypared lizovuka futhi, kepha izinga eliphakeme lokufaka esikhundleni lizonciphisa iphuzu laso le-gel; Isizathu ngenxa yokwakheka kobude obukhethekile bekhabhoni ye-hydroxypropyl gerop, i-hydroxypropylication ephansi, izibopho ezibuthakathaka ze-hydrogen ngaphakathi naphakathi kwama-molecule kuma-molecule e-cellulose macromolecule, kanye namaqembu e-hydrophilic hydroxyls emakhethini egatsha. Amanzi anamandla. Ngakolunye uhlangothi, uma ukufakwa esikhundleni kuphezulu, kuzoba ne-polymerization eqenjini eliseceleni, okuqukethwe okuhlobene neHydroxyl Group kuzokwehla, i-hydrophobicicity izokwenyuswa, futhi i-solubelity izoncishiswa.
Ukukhiqizwa kanye nokucwaninga kweI-Cellulose Etherunomlando omude. Ngo-1905, iSuida yaqala ukubika ngokuthethelwa kwe-cellulose, eyayinama-methylated nge-dimethyl sulfate. Abakwa-Alekl be-ALKYL be-Nonionic babenelungelo lobunikazi nguLilienfeld (1912), i-Dreyfus (1914) kanye nama-leuchs (1920) ama-sulfose ancibilika noma ancibilike ama-cellule cellulose, ngokulandelana. UBucler noGomberg bakhiqiza i-benzyl cellulose ngonyaka we-1921, iCarboxymethyl celtule yasungulwa okokuqala nguJansswethyl cellulose ngonyaka we-1920. Ekuqaleni kwama-1920s, ama-carboxymethylcellose ayenziwa ngezentengiselwano eJalimane. Kusukela ngo-1937 kuya ku-1938, ukukhiqizwa kwezimboni kwe-MC ne-HEC kwafezeka e-United States. ISweden yaqala ukukhiqizwa kwe-EHEC enikezela ngamanzi ngo-1945. Ngemuva kuka-1945, ukukhiqizwa kwe-cellulose ether kwandisa ngokushesha entshonalanga yeYurophu, e-United States naseJapan. Ekupheleni kuka-1957, iChina CMC yaqala ukukhiqizwa efektri yaseShanghai Relseloid. Ngo-2004, umthamo wezwe lami uzoba amathani angama-30,000 e-ionic ether namathani ayi-10,000 e-ether engeyona eye-ionic ether. Ngo-2007, izofinyelela amathani angama-100,000 e-Ionic Ether namathani angama-40,000 e-ether ye-nonic. Izinkampani zobuchwepheshe ezihlangene ekhaya nakwamanye amazwe nazo zivela njalo, kanti umthamo we-cellulose ether ether
Eminyakeni yamuva nje, ama-monoethers amaningi we-cellulose kanye nezitha ezixubile ezinamagugu ahlukene we-DS, ama-viscosities, ubumsulwa kanye nezimbobo ze-bhedi kuye kwathuthukiswa ngokuqhubekayo. Njengamanje, ukugxila kwentuthuko emkhakheni we-cellulose izithathekisa ukwamukela ubuchwepheshe bokukhiqiza okuthuthukile, ubuchwepheshe obusha bokulungiselela, imishini emisha, imikhiqizo emisha, imikhiqizo esezingeni eliphakeme, nemikhiqizo ehlelekile kufanele icwaningwe ngokwezobuchwepheshe.
Isikhathi Seposi: APR-28-2024