Mubvunzo unokurumidza nezve cellulose ethers

Cellulose ethers iboka rakasiyana-siyana remakemikari emushonga anobva ku cellulose, inova ndiyo yakawanda organic polymer paNyika. Aya makomisheni akawana kushandiswa kwakapararira mumaindasitiri akasiyana nekuda kweakasarudzika zvivakwa uye zvakasiyana-siyana zvekushandisa.

Chimiro neZvinhu zveCellulose Ethers
Cellulose, polysaccharide inosanganisira kudzokorora mayuniti eglucose akabatanidzwa ne β (1 → 4) glycosidic bonds, inoshanda sechinhu chekutanga chekugadzirisa mumasero emadziro emiti. Cellulose ethers inogadzirwa nekugadzirisa makemikari mapoka ehydroxyl (-OH) aripo mu cellulose molecule. Mhando dzakawanda dzema cellulose ethers dzinosanganisira methyl cellulose (MC), hydroxypropyl cellulose (HPC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), uye ethyl hydroxyethyl cellulose (EHEC).

Kutsiviwa kwemapoka e-hydroxyl mu cellulose nemapoka akasiyana-siyana anoshanda anoshandura maitiro ezvinoita cellulose ethers. Semuenzaniso, kuunzwa kwemapoka emethyl kunowedzera kunyungudika kwemvura uye firimu-kugadzira zvivakwa, zvichiita kuti MC ive yakakodzera kunyorera mumishonga, zvigadzirwa zvekudya, uye zvekuvakisa. Saizvozvo, kubatanidzwa kwemapoka ehydroxyethyl kana hydroxypropyl kunovandudza kuchengetedza kwemvura, kugona kukora, uye kunamatira, zvichiita kuti HEC neHPC zviwedzere zvakakosha muzvigadzirwa zvekuchengeta, pendi, uye zvinonamira. Carboxymethyl cellulose, inogadzirwa nekutsiva mapoka ehydroxyl nemapoka ecarboxymethyl, inoratidza kuchengetedza kwemvura kwakanaka, kugadzikana, uye kukora zvivakwa, zvichiita kuti ishandiswe zvakanyanya muindasitiri yechikafu, mishonga, uye sekuwedzera kwemvura yekuchera muchikamu chemafuta negesi.

The degree of substitution (DS), iyo inoratidza avhareji yenhamba yeakatsiviwa hydroxyl mapoka paglucose unit mu cellulose, inopesvedzera zvakanyanya maitiro e cellulose ethers. Hushe hweDS hwepamusoro hunowanzo konzera kunyungudika, kupenya, uye kugadzikana, asi kutsiva zvakanyanya kunogona kukanganisa biodegradability uye zvimwe zvinodikanwa zve cellulose ethers.

Synthesis yeCellulose Ethers
Iko kuumbwa kwe cellulose ethers kunosanganisira kuita kwemakemikari kunounza mapoka anotsiva pane cellulose musana. Imwe yenzira dzakajairika dzekugadzira cellulose ethers ndeye etherification ye cellulose uchishandisa reagents akakodzera pasi pemamiriro akadzorwa.

Semuyenzaniso, kuumbwa kwemethyl cellulose kunowanzo sanganisira kuita kweselulosi ine alkali simbi hydroxides kugadzira iyo alkali cellulose, inoteverwa nekurapwa nemethyl chloride kana dimethyl sulfate kuunza methyl mapoka pane cellulose cheni. Saizvozvowo, hydroxypropyl cellulose uye hydroxyethyl cellulose inogadzirwa nekuita cellulose nepropylene oxide kana ethylene oxide, zvichiteerana, muhupo hwe alkali catalysts.

Carboxymethyl cellulose inogadzirwa kuburikidza nekuita kwe cellulose ine sodium hydroxide uye chloroacetic acid kana yayo sodium munyu. Iyo carboxymethylation process inoitika kuburikidza neiyo nucleophilic substitution, apo iyo hydroxyl boka re cellulose rinosangana ne chloroacetic acid kuumba carboxymethyl ether linkage.

Iyo synthesis ye cellulose ethers inoda kungwarira kudzora kwemamiriro ekuita, senge tembiricha, pH, uye nguva yekuita, kuti uwane iyo inodiwa dhigirii yekutsiva uye zvigadzirwa zvechigadzirwa. Pamusoro pezvo, nhanho dzekuchenesa dzinowanzo shandiswa kubvisa ne-zvigadzirwa uye tsvina, kuve nechokwadi chemhando uye kuenderana kweselulosi ethers.

Zvishandiso zveCellulose Ethers
Cellulose ethers inowana kushandiswa kwakapararira mumaindasitiri akasiyana siyana nekuda kwezvakasiyana zvivakwa uye kushanda. Zvimwe zvezvishandiso zvakakosha zvinosanganisira:

Indasitiri yeChikafu:Cellulose etherssenge carboxymethyl cellulose inowanzoshandiswa seyakakora maajenti, stabilizers, uye emulsifiers muzvigadzirwa zvekudya zvakaita sesosi, madhirezi, uye ice cream. Ivo vanovandudza magadzirirwo, viscosity, uye kugadzikana pasherufu uku vachiwedzera muromo uye kuburitsa flavour.

Pharmaceuticals: Methyl cellulose uye hydroxypropyl cellulose inoshandiswa zvakanyanya mukugadzirwa kwemishonga semabhandi, disintegrants, uye anodzorwa-anoburitsa maajenti mumapiritsi, capsules, uye topical formulations. Aya cellulose ethers anovandudza kuendeswa kwezvinodhaka, bioavailability, uye kutevedzera kwemurwere.

Zvishandiso Zvekuvaka: Methyl cellulose uye hydroxyethyl cellulose inoshandiswa muindasitiri yekuvaka sekuwedzera mune simende-based madhaka, plasters, uye mataira anonamira kuti awedzere kushanda, kuchengetedza mvura, uye anonamira zvivakwa. Vanovandudza kubatana, kuderedza kuputika, uye kuwedzera kushanda kwezvinhu zvekuvaka.

Zvigadzirwa Zvekuchengeta Pamunhu: Hydroxyethyl cellulose uye hydroxypropyl cellulose zvinhu zvakajairika muzvigadzirwa zvekuchengeta senge shampoos, lotions, uye makirimu anofanirwa t.

o kukora, kudzikamisa, uye kugadzira firimu. Vanovandudza kusimba kwechigadzirwa, magadzirirwo, uye kunzwa kweganda uku vachiwedzera kugadzikana kwekugadzirisa.

Paints and Coatings: Cellulose ethers inoshanda serheology modifiers, thickeners, uye stabilizers mupendi, coatings, and adhesives, inovandudza maapplication properties, flow behavior, uye magadzirirwo emafirimu. Vanowedzera viscosity control, sag resistance, uye kugadzikana kwemavara mumvura-based formulations.

Indasitiri yeOiri neGasi: Carboxymethyl cellulose inoshandiswa seyakagadziriswa viscosity uye yekurasikirwa kwemvura yekudzora mumiriri mukuchera zvinwiwa zveoiri uye gasi kuongorora nekugadzira. Inonatsiridza rheology yemvura, kuchenesa gomba, uye kugadzikana kwegomba uku ichidzivirira kukuvara kwekuumbwa.

Indasitiri yeMicheka: Cellulose ethers inoshandiswa mukudhinda machira, kudhaya, uye kupedzisa maitiro ekusimudzira tsananguro yekudhinda, goho remavara, uye kupfava kwejira. Ivo vanofambisa pigment kupararira, kunamatira kune fiber, uye kushambidza kukurumidza mumachira ekushandisa.

Cellulose ethersinomiririra boka rakasiyana-siyana remakemikari emakemikari anobva ku cellulose, achipa huwandu hwakasiyana hwezvivakwa uye zvinoshanda kune akasiyana maindasitiri ekushandisa. Kuburikidza nekugadziriswa kwemakemikari kugadziridzwa kwemusana we cellulose, cellulose ethers inoratidza hunhu hunodiwa senge kunyungudika kwemvura, viscosity control, uye kugadzikana, zvichiita kuti zvive zvakakosha zvekuwedzera mumaindasitiri kubva pakudya nemishonga kusvika pakuvaka uye machira. Sezvo kudiwa kwezvinhu zvinogoneka uye zvine hushamwari kwezvakatipoteredza kuri kuramba kuchikura, cellulose ethers vakagadzirira kuita basa rakakosha mukuzadzisa zvinodikanwa zvinoshanduka zvemaindasitiri emazuva ano uku vachideredza kukanganisa kwezvakatipoteredza.