Bawo ni lati ṣe Cellulose ether?

Cellulose ether jẹ iru itọsẹ cellulose ti a gba nipasẹ iyipada etherification ti cellulose. O ti wa ni o gbajumo ni lilo nitori awọn oniwe-o tayọ nipon, emulsification, idadoro, fiimu Ibiyi, aabo colloid, ọrinrin idaduro, ati adhesion-ini. O ṣe ipa pataki ninu idagbasoke ti ọrọ-aje orilẹ-ede ni iwadii ijinle sayensi ati awọn apa ile-iṣẹ bii ounjẹ, oogun, ṣiṣe iwe, awọn aṣọ, awọn ohun elo ile, imularada epo, awọn aṣọ ati awọn paati itanna. Ninu iwe yii, ilọsiwaju iwadi ti iyipada etherification ti cellulose jẹ atunyẹwo.

Celluloseetherjẹ julọ lọpọlọpọ Organic polima ni iseda. O jẹ isọdọtun, alawọ ewe ati biocompatible. O jẹ ohun elo aise pataki fun imọ-ẹrọ kemikali. Ni ibamu si awọn oriṣiriṣi awọn aropo lori moleku ti a gba lati inu ifaseyin etherification, o le pin si awọn ethers ẹyọkan ati adalu cellulose ethers.Nibi awa ṣe atunyẹwo ilọsiwaju iwadi lori iṣelọpọ ti awọn ethers ẹyọkan, pẹlu awọn ethers alkyl, awọn ethers hydroxyalkyl, awọn ethers carboxyalkyl, ati awọn ethers adalu.

Awọn ọrọ pataki: cellulose ether, etherification, nikan ether, adalu ether, iwadi ilọsiwaju

1.Etherification lenu ti cellulose

Idahun etherification ti cellulose ether is the most important cellulose derivatization reaction.Etherification of cellulose is a series of derivatives produced by the reaction of hydroxyl group on cellulose molikula chains with alkylating agents labẹ awọn ipo ipilẹ. Ọpọlọpọ awọn iru awọn ọja ether cellulose wa, eyiti o le pin si awọn ethers ẹyọkan ati awọn ethers ti a dapọ ni ibamu si awọn aropo oriṣiriṣi lori awọn ohun elo ti a gba lati inu ifaseyin etherification. Awọn ethers ẹyọkan ni a le pin si awọn ethers alkyl, awọn ethers hydroxyalkyl ati awọn ethers carboxyalkyl, ati awọn ethers ti o dapọ tọka si awọn ethers pẹlu awọn ẹgbẹ meji tabi diẹ sii ti a ti sopọ ni eto molikula. Lara awọn ọja ether cellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) jẹ aṣoju, laarin eyiti Diẹ ninu awọn ọja ti jẹ iṣowo.

2.Synthesis ti cellulose ether

2.1 Akopọ ti a nikan ether

Awọn ethers ẹyọkan pẹlu awọn ethers alkyl (gẹgẹbi ethyl cellulose, propyl cellulose, phenyl cellulose, cyanoethyl cellulose, bbl), hydroxyalkyl ethers (gẹgẹ bi awọn hydroxymethyl cellulose, hydroxyethyl cellulose, bbl), carboxyalkyl ethers (gẹgẹ bi awọn carboxymethyl cellulose cellulose, carboxymethyl cellulose). ati be be lo).

2.1.1 Akopọ ti alkyl ethers

Berglund et al akọkọ ṣe itọju cellulose pẹlu ojutu NaOH ti a ṣafikun pẹlu ethyl kiloraidi, lẹhinna fi kun methyl kiloraidi ni iwọn otutu ti 65°C si 90°C ati titẹ ti 3bar si 15bar, ati fesi lati gbejade ether cellulose methyl. Ọna yii le ṣiṣẹ daradara Lati gba awọn ethers methyl cellulose ti omi-tiotuka pẹlu awọn iwọn oriṣiriṣi ti aropo.

Ethylcellulose jẹ granule thermoplastic funfun tabi lulú. Awọn ọja gbogbogbo ni 44% ~ 49% ethoxy ninu. Tiotuka ninu ọpọlọpọ awọn olomi Organic, insoluble ninu omi. awọn ti ko nira tabi owu linters pẹlu 40% ~ 50% soda hydroxide olomi ojutu, ati awọn alkalized cellulose ti a ethoxylated pẹlu ethyl kiloraidi lati gbe ethyl cellulose. ni aṣeyọri ti iṣelọpọ ethyl cellulose (EC) pẹlu akoonu ethoxy kan ti 43.98% nipasẹ ọna igbese kan nipa didahun cellulose pẹlu apọju ethyl kiloraidi ati iṣuu soda hydroxide, ni lilo toluene bi diluent. Toluene ti lo bi diluent ninu idanwo naa. Lakoko iṣesi etherification, ko le ṣe igbelaruge itankale ethyl kiloraidi nikan si cellulose alkali, ṣugbọn tun tu ethyl cellulose ti o rọpo pupọ. Lakoko ifarabalẹ, apakan ti a ko dahun le ṣe afihan nigbagbogbo, ṣiṣe aṣoju etherification O rọrun lati gbogun, nitorinaa iṣesi ethylation yipada lati oriṣiriṣi si isokan, ati pinpin awọn aropo ninu ọja naa jẹ aṣọ diẹ sii.

ti a lo ethyl bromide bi oluranlowo etherification ati tetrahydrofuran bi diluent lati synthesize ethyl cellulose (EC), o si ṣe afihan igbekalẹ ọja nipasẹ spectroscopy infurarẹẹdi, resonance magnetic resonance ati gel permeation chromatography. O ti wa ni iṣiro pe iwọn aropo ti ethyl cellulose ti iṣelọpọ jẹ nipa 2.5, pinpin ibi-ara molikula jẹ dín, ati pe o ni solubility ti o dara ni awọn olomi Organic.

cyanoethyl cellulose (CEC) nipasẹ isokan ati orisirisi awọn ọna lilo cellulose pẹlu o yatọ si iwọn ti polymerization bi aise ohun elo, ati ki o pese sile ipon CEC awo awọn ohun elo nipa ojutu simẹnti ati ki o gbona titẹ. Awọn membran CEC porous ni a pese sile nipasẹ imọ-ẹrọ ipinya-ipin ti o ni ipa (NIPS), ati barium titanate/cyanoethyl cellulose (BT/CEC) nanocomposite membrane awọn ohun elo ti a pese sile nipasẹ imọ-ẹrọ NIPS, ati awọn ẹya ati awọn ohun-ini wọn ti ṣe iwadi.

lo awọn ara-ni idagbasoke cellulose epo (alkali / urea ojutu) bi awọn lenu alabọde to homogeneously synthesize cyanoethyl cellulose (CEC) pẹlu acrylonitrile bi awọn etherification oluranlowo, ati ki o waiye iwadi lori awọn be, ini ati awọn ohun elo ti ọja. iwadi ni ijinle. Ati nipa ṣiṣakoso awọn ipo ifaseyin oriṣiriṣi, lẹsẹsẹ ti CEC pẹlu awọn iye DS ti o wa lati 0.26 si 1.81 le ṣee gba.

2.1.2 Kokoro ti hydroxyalkyl ethers

Fan Junlin et al pese sile hydroxyethyl cellulose (HEC) ni a 500 L reactor lilo owu refaini bi aise ohun elo ati ki o 87.7% isopropanol-omi bi epo nipasẹ ọkan-igbese alkalization, igbese-nipasẹ-Igbese yomijade ati igbese-nipasẹ-Igbese etherification. . Awọn abajade fihan pe hydroxyethyl cellulose ti a pese silẹ (HEC) ni aropo molar MS ti 2.2-2.9, ti o de iwọn iwọn didara kanna bi ọja Dows 250 HEC ti iṣowo pẹlu aropo molar ti 2.2-2.4. Lilo HEC ni iṣelọpọ awọ-ara latex le mu ilọsiwaju-fiimu ati awọn ohun-ini ipele ti awọ latex.

Liu Dan ati awọn miran sísọ igbaradi ti quaternary ammonium iyọ cationic hydroxyethyl cellulose nipasẹ awọn ologbele-gbẹ ọna ti hydroxyethyl cellulose (HEC) ati 2,3-epoxypropyltrimethylammonium kiloraidi (GTA) labẹ awọn igbese ti alkali catalysis. ether awọn ipo. Ipa ti fifi cationic hydroxyethyl cellulose ether sori iwe ni a ṣe iwadii. Awọn abajade esiperimenta fihan pe: ninu pulp igilile bleached, nigbati iwọn iyipada ti cationic hydroxyethyl cellulose ether jẹ 0.26, iwọn idaduro lapapọ pọ si nipasẹ 9%, ati iwọn isọ omi pọ si nipasẹ 14%; ni bleached hardwood pulp, nigbati Nigbati iye cationic hydroxyethyl cellulose ether jẹ 0.08% ti okun ti ko nira, o ni ipa imudara pataki lori iwe; ti o tobi ìyí ti fidipo ti cationic cellulose ether, ti o tobi ni cationic idiyele iwuwo, ati awọn ti o dara ipa ipa.

Zhanhong nlo ọna iṣelọpọ omi-alakoso lati mura hydroxyethyl cellulose pẹlu iye iki ti 5×104mPa·s tabi diẹ ẹ sii ati iye eeru ti o kere ju 0.3% nipasẹ ilana-igbesẹ meji ti alkalization ati etherification. Awọn ọna alkalization meji ni a lo. Ọna akọkọ ni lati lo acetone bi diluent. Ohun elo aise cellulose jẹ ipilẹ taara ni ifọkansi kan ti ojutu olomi soda hydroxide. Lẹhin ifaseyin basification ti wa ni ti gbe jade, ohun etherification oluranlowo ti wa ni afikun si taara gbe jade awọn etherification lenu. Awọn keji ọna ni wipe awọn cellulose aise awọn ohun elo ti wa ni alkalized ni ohun olomi ojutu ti soda hydroxide ati urea, ati awọn alkali cellulose pese sile nipa yi ọna gbọdọ wa ni squeezed lati yọ excess lye ṣaaju ki o to etherification lenu. Awọn abajade esiperimenta fihan pe awọn ifosiwewe bii iye diluent ti a yan, iye ti ethylene oxide ti a ṣafikun, akoko alkalization, iwọn otutu ati akoko iṣesi akọkọ, ati iwọn otutu ati akoko ifasẹyin keji gbogbo ni ipa nla lori iṣẹ ṣiṣe. ti ọja.

Xu Qin et al. ti gbe jade etherification lenu ti alkali cellulose ati propylene oxide, ati sise hydroxypropyl cellulose (HPC) pẹlu kekere aropo ìyí nipa gaasi-ri to alakoso ọna. Awọn ipa ti ida pupọ ti ohun elo afẹfẹ propylene, ipin fun pọ ati iwọn otutu etherification lori iwọn etherification ti HPC ati lilo imunadoko ti propylene oxide ni a ṣe iwadi. Awọn abajade fihan pe awọn ipo iṣelọpọ ti o dara julọ ti HPC jẹ ida ibi-pupọ propylene oxide 20% (ipin ibi-pupọ si cellulose), ipin extrusion cellulose alkali 3.0, ati iwọn otutu etherification 60°C. Idanwo igbekalẹ ti HPC nipasẹ isọdọtun oofa iparun fihan pe iwọn etherification ti HPC jẹ 0.23, iwọn lilo ti o munadoko ti oxide propylene jẹ 41.51%, ati pq molikula cellulose ti sopọ ni aṣeyọri pẹlu awọn ẹgbẹ hydroxypropyl.

Kong Xingjie et al. hydroxypropyl cellulose ti a pese sile pẹlu omi ionic bi epo lati mọ iṣesi isokan ti cellulose lati le mọ ilana ilana ilana ati awọn ọja. Lakoko idanwo naa, omi imidazole fosifeti ionic sintetiki 1, 3-diethylimidazole diethyl fosifeti ni a lo lati tu microcrystalline cellulose, ati hydroxypropyl cellulose ti gba nipasẹ alkalization, etherification, acidification, ati fifọ.

2.1.3 Kokoro ti carboxyalkyl ethers

Awọn julọ aṣoju carboxymethyl cellulose ni carboxymethyl cellulose (CMC). Ojutu olomi ti carboxymethyl cellulose ni awọn iṣẹ ti o nipọn, fifin fiimu, mimu, idaduro omi, idaabobo colloid, emulsification ati idadoro, ati pe a lo ni lilo pupọ ni fifọ. Pharmaceuticals, ounje, toothpaste, hihun, titẹ sita ati dyeing, papermaking, Epo ilẹ, iwakusa, oogun, amọ, itanna irinše, roba, kun, ipakokoropaeku, Kosimetik, alawọ, pilasitik ati epo liluho, ati be be lo.

Ni ọdun 1918, Jẹmánì E. Jansen ṣe agbekalẹ ọna iṣelọpọ ti carboxymethyl cellulose. Ni ọdun 1940, ile-iṣẹ Kalle ti Ile-iṣẹ German IG Farbeninaustrie ṣe akiyesi iṣelọpọ ile-iṣẹ. Ni ọdun 1947, Ile-iṣẹ Kemikali Wyandotle ti Amẹrika ni aṣeyọri ni idagbasoke ilana iṣelọpọ ti nlọ lọwọ. orilẹ-ede mi akọkọ fi sinu iṣelọpọ ile-iṣẹ CMC ni Shanghai Celluloid Factory ni 1958. Carboxymethyl cellulose jẹ ether cellulose ti a ṣe lati inu owu ti a ti tunṣe labẹ iṣẹ ti sodium hydroxide ati chloroacetic acid. Awọn ọna iṣelọpọ ile-iṣẹ rẹ le pin si awọn ẹka meji: ọna orisun omi ati ọna ti o da lori epo ni ibamu si oriṣiriṣi etherification media. Ilana nipa lilo omi bi alabọde ifasẹyin ni a pe ni ọna alabọde omi, ati ilana ti o ni epo-ara ti o ni nkan ti o wa ninu ifasẹyin ni a npe ni ọna epo.

Pẹlu jinlẹ ti iwadii ati ilosiwaju ti imọ-ẹrọ, awọn ipo ifasẹ tuntun ti lo si iṣelọpọ ti cellulose carboxymethyl, ati pe eto epo tuntun ni ipa pataki lori ilana ifaseyin tabi didara ọja. Olaru et al. ri pe ifaseyin carboxymethylation ti cellulose nipa lilo ethanol-acetone adalu eto dara ju ti ethanol tabi acetone nikan. Nicholson et al. Ninu eto, CMC pẹlu iwọn kekere ti aropo ti pese. Philipp et al pese sile gíga CMC pẹlu N-methylmorpholine-N oxide ati N, N dimethylacetamide/lithium kiloraidi epo awọn ọna ṣiṣe lẹsẹsẹ. Cai et al. ni idagbasoke ọna kan fun igbaradi CMC ni NaOH / urea epo eto. Ramos et al. lo DMSO/tetrabutylammonium fluoride ionic olomi eto bi a epo lati carboxymethylate awọn cellulose aise awọn ohun elo ti refaini lati owu ati sisal, ati ki o gba a CMC ọja pẹlu kan aropo ìyí bi ga bi 2.17. Chen Jinghuan et al. cellulose ti a lo pẹlu ifọkansi pulp giga (20%) bi ohun elo aise, iṣuu soda hydroxide ati acrylamide bi awọn reagents iyipada, ti a ṣe iyipada iyipada carboxyethylation ni akoko ṣeto ati iwọn otutu, ati nikẹhin gba cellulose ipilẹ carboxyethyl. Akoonu carboxyethyl ti ọja ti a tunṣe le ṣe ilana nipasẹ yiyipada iye iṣuu soda hydroxide ati acrylamide.

2.2 Kokoro ti adalu ethers

Hydroxypropyl methyl cellulose ether jẹ iru ti kii-pola cellulose ether tiotuka ninu omi tutu ti a gba lati inu cellulose adayeba nipasẹ alkalization ati iyipada etherification. O ti wa ni alkalized pẹlu iṣuu soda hydroxide ojutu ati fi kun iye kan ti Iye isopropanol ati toluene epo, oluranlowo etherification ti o gba ni methyl kiloraidi ati propylene oxide.

Dai Mingyun et al. ti a lo hydroxyethyl cellulose (HEC) bi ẹhin ti polymer hydrophilic, ati tirun oluranlowo hydrophobizing butyl glycidyl ether (BGE) lori ẹhin ẹhin nipasẹ iṣesi etherification lati ṣatunṣe ẹgbẹ ẹgbẹ hydrophobic butyl. Iwọn iyipada ti ẹgbẹ, ki o ni iye iwọntunwọnsi hydrophilic-lipophilic ti o yẹ, ati pe 2-hydroxy-3-butoxypropyl hydroxyethyl cellulose (HBPEC) ti o dahun iwọn otutu ti pese; ohun-ini ti o ni iwọn otutu ti pese sile Awọn ohun elo iṣẹ-ṣiṣe ti o da lori cellulose pese ọna titun fun ohun elo ti awọn ohun elo iṣẹ-ṣiṣe ni awọn aaye ti idasilẹ ti oogun ati isedale.

Chen Yangming ati awọn miiran lo hydroxyethyl cellulose bi ohun elo aise, ati ninu eto ojutu isopropanol, ṣafikun iye kekere ti Na2B4O7 si ifaseyin fun iṣesi isokan lati ṣeto idapọ ether hydroxyethyl carboxymethyl cellulose. Ọja naa jẹ lẹsẹkẹsẹ ninu omi, ati iki jẹ iduroṣinṣin.

Wang Peng nlo owu ti a ti mọ cellulose adayeba gẹgẹbi ohun elo aise ipilẹ, o si nlo ilana etherification kan-igbesẹ kan lati ṣe agbejade cellulose carboxymethyl hydroxypropyl pẹlu iṣesi aṣọ, iki giga, resistance acid ti o dara ati resistance iyọ nipasẹ alkalization ati awọn aati etherification Compound ether. Lilo ilana etherification ọkan-igbesẹ, carboxymethyl hydroxypropyl cellulose ti a ṣejade ni iyọda iyọ ti o dara, resistance acid ati solubility. Nipa yiyipada awọn iye ibatan ti propylene oxide ati chloroacetic acid, awọn ọja pẹlu oriṣiriṣi carboxymethyl ati awọn akoonu hydroxypropyl ni a le pese sile. Awọn abajade idanwo fihan pe carboxymethyl hydroxypropyl cellulose ti a ṣe nipasẹ ọna igbese kan ni ọna iṣelọpọ kukuru, agbara epo kekere, ati pe ọja naa ni resistance to dara julọ si awọn iyọ monovalent ati divalent ati resistance acid to dara. Ti a ṣe afiwe pẹlu awọn ọja ether cellulose miiran, o ni ifigagbaga ni okun sii ni awọn aaye ti ounjẹ ati iṣawari epo.

Hydroxypropylmethylcellulose (HPMC) jẹ ẹya ti o pọ julọ ati ti o ṣiṣẹ julọ laarin gbogbo iru cellulose, ati pe o tun jẹ aṣoju aṣoju ti iṣowo laarin awọn ethers adalu. Ni ọdun 1927, hydroxypropylmethylcellulose (HPMC) ti ṣajọpọ ni aṣeyọri ati ti o ya sọtọ. Ni 1938, Dow Kemikali Co. ti Orilẹ Amẹrika ṣe akiyesi iṣelọpọ ile-iṣẹ ti methyl cellulose ati ṣẹda aami-iṣowo ti a mọ daradara "Methocel". Ṣiṣejade ile-iṣẹ nla ti hydroxypropyl methylcellulose bẹrẹ ni Amẹrika ni ọdun 1948. Ilana iṣelọpọ ti HPMC le pin si awọn ẹka meji: ọna ipele gaasi ati ọna ipele omi. Ni lọwọlọwọ, awọn orilẹ-ede ti o ni idagbasoke bii Yuroopu, Amẹrika ati Japan n gba ilana ipele gaasi diẹ sii, ati iṣelọpọ inu ile ti HPMC da lori ilana ilana ipele omi.

Zhang Shuangjian ati awọn miiran ti refaini owu lulú bi aise awọn ohun elo ti, alkalized o pẹlu soda hydroxide ni ifaseyin epo alabọde toluene ati isopropanol, etherified o pẹlu etherifying oluranlowo propylene oxide ati methyl kiloraidi, reacted ati ki o pese a irú ti ese hydroxypropyl methyl oti mimọ cellulose ether.

3. Outlook

Cellulose jẹ kemikali pataki ati ohun elo aise kemikali ti o jẹ ọlọrọ ni awọn orisun, alawọ ewe ati ore ayika, ati isọdọtun. Awọn itọsẹ ti iyipada etherification cellulose ni iṣẹ ti o dara julọ, ọpọlọpọ awọn lilo ati awọn ipa lilo ti o dara julọ, ati pade awọn iwulo ti aje orilẹ-ede si iye nla. Ati awọn iwulo idagbasoke awujọ, pẹlu ilọsiwaju imọ-ẹrọ ti o tẹsiwaju ati riri ti iṣowo ni ọjọ iwaju, ti awọn ohun elo sintetiki ati awọn ọna sintetiki ti awọn itọsẹ cellulose le jẹ iṣelọpọ diẹ sii, wọn yoo lo ni kikun ati mọ awọn ohun elo ti o gbooro sii. Iye.