Focus on Cellulose ethers

Nzira yekuita sei cellulose ether?

Nzira yekuita sei cellulose ether?

Cellulose ether rudzi rwekubuda kwe cellulose inowanikwa ne etherification gadziriso ye cellulose.Iyo inoshandiswa zvakanyanya nekuda kwekunaka kwayo kukora, emulsification, kumiswa, kuumbwa kwemafirimu, inodzivirira colloid, kuchengetedza mwando, uye adhesion zvivakwa.Inobata basa rakakosha mukusimudzira hupfumi hwenyika mukutsvagisa kwesainzi uye zvikamu zveindasitiri zvakaita sechikafu, mushonga, kugadzira mapepa, machira, zvekuvakisa, kudzoreredza mafuta, machira uye zvemagetsi zvikamu.Mune bepa rino, kufambira mberi kwekutsvagisa kwe etherification shanduko ye cellulose inoongororwa.

Celluloseetherndiyo yakanyanya kuwanda organic polymer mune zvakasikwa.Iyo inogona kuvandudzwa, yakasvibira uye biocompatible.Icho chakakosha chakakosha mbishi zvinhu zvemakemikari engineering.Zvinoenderana neakasiyana anotsiva pamorekuru anowanikwa kubva kune etherification reaction, inogona kupatsanurwa kuita ether imwe uye yakasanganiswa. cellulose ethers.Tiri pano inoongorora kufambira mberi kwetsvakiridzo pakuumbwa kweethers imwechete, kusanganisira alkyl ethers, hydroxyalkyl ethers, carboxyalkyl ethers, uye ethers dzakasanganiswa.

Mazwi akakosha: cellulose ether, etherification, ether imwe, ether yakasanganiswa, kufambira mberi kwekutsvakurudza

 

1.Etherification reaction ye cellulose

 

Iyo etherification reaction ye cellulose ether ndiyo inonyanya kukosha cellulose derivatization reaction.Etherification ye cellulose inotevedzana yezvinyorwa zvinogadzirwa nekuita kwemapoka e-hydroxyl pa cellulose molecular chains ane alkylating agents pasi pemamiriro e-alkaline.Kune mhando dzakawanda dzezvigadzirwa zve cellulose ether, zvinogona kupatsanurwa kuita ether imwe chete uye yakasanganiswa ether zvichienderana neakasiyana anotsiva pamamorekuru anowanikwa kubva kune etherification reaction.Ethers imwechete inogona kupatsanurwa kuita alkyl ethers, hydroxyalkyl ethers uye carboxyalkyl ethers, uye yakasanganiswa ethers inoreva ethers ane maviri kana anopfuura mapoka akabatana mune molecular chimiro.Pakati pezvigadzirwa zve cellulose ether, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) inomiririrwa, pakati payo Zvimwe zvigadzirwa zvakatengeswa.

 

2.Synthesis ye cellulose ether

 

2.1 Kuumbwa kweether imwe

Ethers imwechete inosanganisira alkyl ethers (senge ethyl cellulose, propyl cellulose, phenyl cellulose, cyanoethyl cellulose, nezvimwewo), hydroxyalkyl ethers (senge hydroxymethyl cellulose, hydroxyethyl cellulose, nezvimwewo ), carboxymethylselulosi, sero cellulose carboxy, carboxymethyl cellulose etc.).

2.1.1 Synthesis yealkyl ethers

Berglund et al akatanga kurapa cellulose neNaOH solution yakawedzerwa ne ethyl chloride, ndokuzowedzera methyl chloride patembiricha ye65.°C kusvika ku90°C uye dzvinyiriro ye3bar kusvika 15bar, uye yakaita kuti ibudise methyl cellulose ether.Iyi nzira inogona kushanda zvakanyanya Kuwana mvura-soluble methyl cellulose ethers ine madhigirii akasiyana ekutsiva.

Ethylcellulose ichena thermoplastic granule kana hupfu.General commodities ine 44% ~ 49% ethoxy.Soluble mune yakawanda organic solvents, isinganyungudika mumvura.the pulp kana donje linters ane 40% ~ 50% sodium hydroxide aqueous solution, uye alkalized cellulose yakaitwa ethoxylated ne ethyl chloride kugadzira ethyl cellulose.yakabudirira kugadzirwa ethyl cellulose (EC) ine ethoxy content ye43.98% nenzira yenhanho imwe chete nekuita seruseru ine yakawandisa ethyl chloride uye sodium hydroxide, uchishandisa toluene se diluent.Toluene yakashandiswa seyakanyorovesa muchiyedzo.Munguva ye etherification reaction, haingogone kukurudzira kupararira kwe ethyl chloride kune alkali cellulose, asiwo kunyungudutsa iyo yakanyanya kutsiva ethyl cellulose.Munguva yekupindura, chikamu chisina kugadziriswa chinogona kuramba chichibudiswa pachena, zvichiita kuti etherification agent Iri nyore kupinda, kuitira kuti ethylation reaction ishanduke kubva kune heterogeneous kusvika kune homogeneous, uye kugoverwa kwezvikamu zvechigadzirwa zvakanyanya kufanana.

yakashandisa ethyl bromide se etherification agent uye tetrahydrofuran se diluent kugadzira ethyl cellulose (EC), uye yakaratidza chimiro chechigadzirwa ne infrared spectroscopy, nuclear magnetic resonance uye gel permeation chromatography.Zvinoverengerwa kuti dhigirii rekutsiva iyo synthesized ethyl cellulose ingangoita 2.5, iyo molecular mass kugovera idiki, uye ine yakanaka solubility muorganic solvents.

cyanoethyl cellulose (CEC) kuburikidza nehomogeneous uye heterogeneous nzira vachishandisa cellulose ine madhigirii akasiyana epolymerization seyakagadzirwa, uye yakagadzirira dense CEC membrane zvinhu nekukandira mhinduro uye kupisa kupisa.Porous CEC membranes yakagadzirirwa ne-solvent-induced phase separation (NIPS) tekinoroji, uye barium titanate/cyanoethyl cellulose (BT/CEC) nanocomposite membrane zvinhu zvakagadzirirwa neNIPS tekinoroji, uye zvimiro zvavo uye zvivakwa zvakadzidzwa.

yakashandisa self-developed cellulose solvent (alkali/urea solution) seyekuita medium to homogeneously synthesize cyanoethyl cellulose (CEC) ine acrylonitrile seye etherification agent, uye yakaita tsvakurudzo pamusoro pechimiro, zvivakwa uye mashandisirwo echigadzirwa.kudzidza zvakadzama.Uye nekudzora mamiriro akasiyana ekuita, nhevedzano yeCECs ine DS kukosha kubva pa0.26 kusvika 1.81 inogona kuwanikwa.

2.1.2 Kusanganiswa kwehydroxyalkyl ethers

Fan Junlin et al vakagadzirira hydroxyethyl cellulose (HEC) mu 500 L reactor vachishandisa donje rakanatswa seyakagadzirwa uye 87.7% isopropanol-mvura seyakanyungudutswa nedanho rimwe alkalization, nhanho-ne-nhanho neutralization uye nhanho-nhanho etherification..Zvigumisiro zvakaratidza kuti yakagadzirwa hydroxyethyl cellulose (HEC) yakanga ine molar substitution MS ye 2.2-2.9, inosvika pachiyero chemhando yakafanana neyekutengesa giredhi Dows 250 HEC chigadzirwa chine molar inotsiva 2.2-2.4.Kushandisa HEC mukugadzira latex pendi kunogona kuvandudza firimu-kuumba uye kuenzanisa zvimiro zvependi yelatex.

Liu Dan nevamwe vakakurukura kugadzirira kwequaternary ammonium salt cationic hydroxyethyl cellulose ne semi-dry method ye hydroxyethyl cellulose (HEC) uye 2,3-epoxypropyltrimethylammonium chloride (GTA) pasi pechiito che alkali catalysis.ether mamiriro.Mhedzisiro yekuwedzera cationic hydroxyethyl cellulose ether pabepa yakaongororwa.Migumisiro yekuedza inoratidza kuti: mu bleached hardwood pulp, apo dhigirii yekutsiva ye cationic hydroxyethyl cellulose ether iri 0.26, huwandu hwekuchengetedza hunowedzera ne9%, uye mvura yekusefa inowedzera ne14%;mu bleached hardwood pulp, apo Kana iyo yakawanda ye cationic hydroxyethyl cellulose ether iri 0.08% ye pulp fiber, ine zvakakosha kusimbisa simba papepa;iyo yakakura dhigirii yekutsiva cationic cellulose ether, yakakura iyo cationic charge density, uye zviri nani iyo yekusimbisa mhedzisiro.

Zhanhong inoshandisa iyo liquid-phase synthesis nzira kugadzira hydroxyethyl cellulose ine viscosity kukosha kwe5.×104mPa·s kana kupfuura uye kukosha kwemadota isingasviki 0.3% kuburikidza nematanho maviri ekuita alkalization uye etherification.Nzira mbiri dze alkalization dzakashandiswa.Nzira yekutanga ndeyokushandisa acetone semushonga.Iyo cellulose raw material yakavakirwa zvakananga mune imwe denderedzwa ye sodium hydroxide aqueous solution.Mushure meiyo basification reaction yaitwa, etherification mumiriri inowedzerwa kuti iite zvakananga etherification reaction.Yechipiri nzira ndeyokuti cellulose mbishi zvinhu inoiswa alkali mumushonga une aqueous wesodium hydroxide uye urea, uye alkali cellulose yakagadzirwa neiyi nzira inofanirwa kusvinwa kuti ibvise lye yakawandisa isati yaitika etherification.Mhedzisiro yekuedza inoratidza kuti zvinhu zvakaita seyakasarudzwa diluent chiyero, huwandu hweethylene oxide yakawedzerwa, nguva yealkalization, tembiricha uye nguva yekutanga kuita, uye tembiricha uye nguva yechiitiko chechipiri zvese zvine simba guru pakuita. zvechigadzirwa.

Xu Qin et al.yakaita etherification reaction yealkali cellulose uye propylene oxide, uye synthesized hydroxypropyl cellulose (HPC) ine yakaderera substitution degree negasi-solid chikamu nzira.Migumisiro yehuwandu hwechikamu chepropylene oxide, squeeze ratio uye etherification tembiricha pachiyero che etherification yeHPC uye kushandiswa kunobudirira kwepropylene oxide kwakadzidzwa.Mhedzisiro yacho yakaratidza kuti iyo optimum synthesis mamiriro eHPC yaive propylene oxide misa chikamu 20% (huwandu huwandu kune cellulose), alkali cellulose extrusion ratio 3.0, uye etherification tembiricha 60.°C. Chimiro chekuedza kweHPC nenyukliya magnetic resonance chinoratidza kuti dhigirii ye etherification yeHPC ndeye 0.23, kushandiswa kunobudirira kwepropylene oxide ndeye 41.51%, uye cellulose molecular chain inobudirira kubatanidzwa nemapoka ehydroxypropyl.

Kong Xingjie et al.yakagadzirira hydroxypropyl cellulose ine ionic fluid semunyungudusa kuti uone homogeneous reaction ye cellulose kuitira kuti uone mutemo wekuita maitiro uye zvigadzirwa.Munguva yekuedza, iyo yakagadzirwa imidazole phosphate ionic liquid 1, 3-diethylimidazole diethyl phosphate yakashandiswa kunyungudutsa microcrystalline cellulose, uye hydroxypropyl cellulose yakawanikwa kuburikidza nealkalization, etherification, acidification, uye washing.

2.1.3 Kusanganiswa kwecarboxyalkyl ethers

Iyo yakajairika carboxymethyl cellulose ndeye carboxymethyl cellulose (CMC).Iyo aqueous solution ye carboxymethyl cellulose ine mabasa ekukora, kugadzira firimu, kusungirirana, kuchengetedza mvura, kudzivirira kwecolloid, emulsification uye kumiswa, uye inoshandiswa zvakanyanya mukuwacha.Mishonga, chikafu, mushonga wemazino, machira, kudhinda nekudhaya, kugadzira mapepa, peturu, migodhi, mishonga, ceramics, zvinhu zvemagetsi, rabha, pendi, mishonga yezvipembenene, zvizorwa, dehwe, mapurasitiki nekuchera mafuta, nezvimwe.

Muna 1918, German E. Jansen akagadzira nzira yekubatanidza yecarboxymethyl cellulose.Muna 1940, fekitori yeKalle yeGerman IG Farbeninaustrie Company yakaona kugadzirwa kwemaindasitiri.Muna 1947, Wyandotle Chemical Company yekuUnited States yakabudirira kugadzira inoenderera mberi yekugadzira.nyika yangu yakatanga kuiswa mukugadzirwa kwemaindasitiri eCMC muShanghai Celluloid Factory muna 1958. Carboxymethyl cellulose is a cellulose ether inogadzirwa kubva mudonje rakanatswa pasi pekuita kwe sodium hydroxide uye chloroacetic acid.Nzira dzayo dzekugadzira maindasitiri dzinogona kukamurwa kuita mapoka maviri: nzira yemvura-yakavakirwa uye solvent-yakavakirwa nzira maererano neyakasiyana etherification midhiya.Maitiro ekushandisa mvura seanoita svikiro anodaidzwa kuti water medium method, uye maitiro ane organic solvent mureaction medium anonzi the solvent method.

Nekudzika kwekutsvagisa uye kufambira mberi kwetekinoroji, mamiriro matsva ekuita akaiswa kune synthesis yecarboxymethyl cellulose, uye iyo itsva solvent system ine chekuita kwakakura pakuita maitiro kana kunaka kwechigadzirwa.Olaru et al.akawana kuti iyo carboxymethylation reaction ye cellulose uchishandisa ethanol-acetone yakasanganiswa system iri nani pane iyo ethanol kana acetone chete.Nicholson et al.Muhurongwa, CMC ine yakaderera dhigirii yekutsiva yakagadzirwa.Philipp et al vakagadzirira yakatsiviwa zvikuru CMC nayo N-methylmorpholine-N oxide uye N, N dimethylacetamide/lithium chloride solvent systems maererano.Cai et al.yakagadzira nzira yekugadzirira CMC muNaOH/urea solvent system.Ramos et al.akashandisa iyo DMSO/tetrabutylammonium fluoride ionic liquid system semunyungudutsa kune carboxymethylate iyo cellulose mbishi zvinhu zvakanatswa kubva mudonje uye sisal, uye yakawana chigadzirwa cheCMC chine dhigirii rekutsiva rinosvika 2.17.Chen Jinghuan et al.yakashandisa cellulose ine yakakwira pulp concentration (20%) seyakabikwa, sodium hydroxide uye acrylamide seyakagadziriswa reagents, ikaitwa carboxyethylation modification reaction panguva yakatarwa uye tembiricha, uye pakupedzisira yakawana carboxyethyl base cellulose.Iyo carboxyethyl yemukati yechigadzirwa yakagadziridzwa inogona kudzorwa nekuchinja huwandu hwe sodium hydroxide uye acrylamide.

2.2 Kubatanidzwa kweether dzakasanganiswa

Hydroxypropyl methyl cellulose ether imhando ye-non-polar cellulose ether inonyungudika mumvura inotonhora inowanikwa kubva kune yakasikwa cellulose kuburikidza nealkalization uye etherification modification.Iyo inogadziriswa nesodium hydroxide solution uye yakawedzera huwandu hweIsopropanol uye toluene solvent, iyo etherification agent inotora is methyl chloride uye propylene oxide.

Dai Mingyun et al.yakashandisa hydroxyethyl cellulose (HEC) semusana wehydrophilic polymer, uye yakanamatira hydrophobizing agent butyl glycidyl ether (BGE) kumusana ne etherification reaction kuti igadzirise boka re hydrophobic butyl boka.Dhigirii yekutsiviwa kweboka, kuitira kuti ive yakakodzera hydrophilic-lipophilic balance value, uye tembiricha inopindura 2-hydroxy-3-butoxypropyl hydroxyethyl cellulose (HBPEC) inogadzirirwa;chivako chinopindura tembiricha chakagadzirirwa Iyo cellulose-yakavakirwa inoshanda zvinhu zvinopa nzira nyowani yekushandiswa kwezvinhu zvinoshanda muminda yezvinodhaka kuburitswa uye biology.

Chen Yangming nevamwe vakashandisa hydroxyethyl cellulose seyakagadzirwa, uye mune isopropanol solution system, yakawedzera huwandu hushoma hweNa2B4O7 kune reactant yehomogeneous reaction kugadzirira yakasanganiswa ether hydroxyethyl carboxymethyl cellulose.Chigadzirwa chacho chiriporipo mumvura, uye Iyo viscosity yakagadzikana.

Wang Peng anoshandisa natural cellulose yakakwenenzverwa donje seyokutanga mbishi, uye anoshandisa imwe-nhanho etherification process kugadzira carboxymethyl hydroxypropyl cellulose ine mauniform reaction, high viscosity, yakanaka asidhi kuramba uye munyu kuramba kuburikidza alkalization uye etherification reactions Compound ether.Uchishandisa imwe-nhanho etherification process, iyo inogadzirwa carboxymethyl hydroxypropyl cellulose ine yakanaka yemunyu kuramba, acid kuramba uye kunyungudika.Nekuchinja huwandu hwehuwandu hwepropylene oxide uye chloroacetic acid, zvigadzirwa zvine akasiyana carboxymethyl uye hydroxypropyl zviri mukati zvinogona kugadzirwa.Mhedzisiro yemuyedzo inoratidza kuti iyo carboxymethyl hydroxypropyl cellulose inogadzirwa neimwe-nhanho nzira ine pfupi yekugadzira kutenderera, yakaderera solvent kushandiswa, uye chigadzirwa chinopikisa zvakanyanya kune monovalent uye divalent munyu uye yakanaka acid kuramba.Kana ichienzaniswa nezvimwe zvigadzirwa zve cellulose ether, ine kukwikwidza kwakasimba muminda yekudya nemafuta ekuongorora.

Hydroxypropylmethylcellulose (HPMC) ndiyo inonyanya kushandiswa uye inonyatsoita zvakasiyana pakati pemarudzi ese e cellulose, uye zvakare inomiririra inomiririra yekushambadzira pakati peethers dzakasanganiswa.Muna 1927, hydroxypropylmethylcellulose (HPMC) yakabudirira kugadzirwa uye yakaparadzaniswa.Muna 1938, Dow Chemical Co. yekuUnited States yakaona kugadzirwa kwemaindasitiri kwemethyl cellulose uye yakagadzira iyo inozivikanwa inozivikanwa yekutengeserana "Methocel".Kugadzirwa kwemaindasitiri kwakakura kwehydroxypropyl methylcellulose yakatanga muUnited States muna 1948. Iyo nzira yekugadzira yeHPMC inogona kukamurwa kuita zvikamu zviviri: gasi chikamu nzira uye liquid chikamu nzira.Parizvino, nyika dzakasimukira dzakaita seEurope, America neJapan dziri kutora chikamu chegasi, uye kugadzirwa kwemumba kweHPMC kunonyanya kuenderana nechikamu chemvura.

Zhang Shuangjian nevamwe vakanatsa donje poda seyakagadzirwa, alkaliized ne sodium hydroxide mu reaction solvent medium toluene uye isopropanol, yakaiisa ne etherifying agent propylene oxide uye methyl chloride, yakaita uye yakagadzira mhando yekukurumidza hydroxypropyl methyl alcohol base cellulose ether.

 

3. Outlook

Cellulose yakakosha kemikari uye makemikari mbishi zvinhu zvakapfuma mune zviwanikwa, zvakasvibira uye zvakatipoteredza zvine hushamwari, uye zvinogona kuvandudzwa.Izvo zvinobva kune cellulose etherification modification zvine mashandiro akanaka, huwandu hwakawanda hwemashandisirwo uye zvakanakisa mhedzisiro yekushandisa, uye inosangana nezvinodiwa zvehupfumi hwenyika kusvika pamwero mukuru.Uye izvo zvinodikanwa zvebudiriro yemagariro, nekuenderera mberi kwehunyanzvi hwekuita uye kuzadziswa kwekutengeserana mune ramangwana, kana zvigadzirwa zvekugadzira uye nzira dzekugadzira dzemaselulosi ezvinobva museru zvingave zvakanyanya maindasitiri, zvichave zvichishandiswa zvizere uye nekuziva huwandu hwakakura hwekushandisa. Value.

 

 


Nguva yekutumira: Jan-06-2023
WhatsApp Online Chat !