Etherification reaction pane cellulose ether

Iyo etherification chiitiko che cellulose chakadzidzwa nemuchina wekukanya uye inosimudzira reactor zvichiteerana, uye hydroxyethyl cellulose uye carboxymethyl cellulose zvakagadzirirwa ne chloroethanol uye monochloroacetic acid zvichiteerana. Mhedzisiro yacho yakaratidza kuti iyo etherification reaction ye cellulose yakaitwa nekukurudzira reactor pasi pemamiriro ekunyanya kusimba agitation. Cellulose ine yakanaka etherification reactivity, iri nani pane nzira yekukanyira mukuvandudza etherification kushanda zvakanaka uye kusimudzira kufambiswa kwechiedza chechigadzirwa mumvura ine aqueous solution.) Naizvozvo, kuvandudza kunyandura kusimba kwemaitiro ekuita inzira iri nani yekuvandudza inotsiva homogeneous cellulose etherification. zvigadzirwa.

Mazwi akakosha:etherification reaction; Cellulose;Hydroxyethyl cellulose; Carboxymethyl cellulose

Mukugadzirwa kwezvakanatswa donje cellulose ether zvigadzirwa, solvent nzira inoshandiswa zvakanyanya uye muchina wekukanya unoshandiswa semidziyo yekuita. Nekudaro, donje cellulose inonyanya kuumbwa nenzvimbo dzekristaro uko mamorekuru anorongwa zvakanaka uye zvakanyanya. Kana muchina wekukanya uchishandiswa semidziyo yekuita, ruoko rwekukanya rwemuchina wekukanya runononoka panguva yekuita, uye kuramba kweetherifying agent kuti ipinde muzvikamu zvakasiyana zve cellulose yakakura uye kumhanya kunonoka, zvichikonzera nguva yakareba yekuita, chikamu chepamusoro chedivi. maitiro uye kugoverwa kusina kuenzana kwemapoka anotsiva pane cellulose molecular cheni.

Kazhinji etherification reaction ye cellulose ndeye heterogeneous reaction kunze nemukati. Kana pasina chekunze dynamic action, etherifying agent inonetsa kupinda mucrystallization zone ye cellulose. Uye kuburikidza nekugadziriswa kwedonje rakanatswa (sekushandisa nzira dzemuviri kuwedzera pamusoro pedonje rakanatswa), panguva imwe chete neinomutsa reactor yemaitiro ekuita, uchishandisa kukurumidza kukurudzira etherification reaction, maererano nekufunga, cellulose inogona kuzvimba zvakanyanya, kuzvimba. ye cellulose amorphous nzvimbo uye crystallization nzvimbo inowanzoenderana, inovandudza maitiro ekuita. Iyo homogeneous kugovera kwe cellulose ether substituents mune heterogeneous etherification reaction system inogona kuwanikwa nekuwedzera ekunze inomutsa simba. Saka ichave iri ramangwana rekusimudzira nyika yedu kugadzira emhando yepamusoro cellulose etherification zvigadzirwa zvine yakamutswa mhando reaction kettle semidziyo yekuita.

1. Chikamu chekuedza

1.1 Yakanatswa donje cellulose mbishi zvinhu zvekuyedzwa

Zvinoenderana neakasiyana maitiro ekushandisa anoshandiswa mukuyedza, nzira dzekutanga dzekotoni cellulose dzakasiyana. Kana iyo kneader ichishandiswa seyekuita midziyo, nzira dzekutanga dzakasiyanawo. Kana iyo kneader ichishandiswa seyakagadziriswa michina, iyo crystallinity yeyakanatswa yekotoni cellulose inoshandiswa ndeye 43.9%, uye avhareji urefu hweyakanatswa donje cellulose ndeye 15 ~ 20mm. Iyo crystallinity yeyakanatswa donje cellulose i32.3% uye avhareji kureba kweyakanatswa donje cellulose isingasviki 1mm apo inobvongodza reactor inoshandiswa semidziyo yekuita.

1.2 Kuvandudzwa kwecarboxymethyl cellulose uye hydroxyethyl cellulose

Kugadzirira kwecarboxymethyl cellulose uye hydroxyethyl cellulose inogona kuitwa nekushandisa 2L kneader seyekuita midziyo (avhareji yekumhanya panguva yekupindura ndeye 50r/min) uye 2L inosimudzira reactor seyekuita midziyo (avhareji yekumhanya panguva yekuita ndeye 500r/min).

Munguva yekupindura, zvese mbishi zvinhu zvinotorwa kubva kune yakasimba quantitative reaction. Chigadzirwa chinowanikwa kubva mukuita chinoshambidzwa ne w = 95% ethanol, uye chobva chaomeswa nekutsvaira kwe24h pasi pekudzvinyirira kwakaipa kwe60 ℃ uye 0.005mpa. Hunyoro hwesample yakawanikwa ndeye w=2.7%±0.3%, uye chigadzirwa chekuongorora chinogezwa kusvika madota emukati w <0.2%.

Matanho ekugadzirira emuchina wekukanyira seyekuita zvekushandisa ndeaya anotevera:

Etherification reaction → kugeza chigadzirwa → kuomesa → grated granulation → kurongedza kunoitwa mukneader.

Matanho ekugadzirira ekusimudzira reactor seyekuita midziyo ndeaya anotevera:

Etherification reaction → kugeza chigadzirwa → kuomesa uye granulation → kurongedza kunoitwa mune yakamutswa reactor.

Zvinogona kuoneka kuti kneader inoshandiswa semagadzirirwo emidziyo yekugadzirira hunhu hwekushomeka kwekuita, kuomesa uye kukuya granulation nhanho nhanho, uye kunaka kwechigadzirwa kuchaderedzwa zvakanyanya mukukuya.

Hunhu hwegadziriro yegadziriro ine yakasimudzwa reactor semagadzirirwo emidziyo ndeaya anotevera: kukwirira kwekuita basa, chigadzirwa granulation hachitore chinyakare granulation process yekuomesa nekukuya, uye kuomesa uye granulation maitiro anoitwa panguva imwe chete. zvigadzirwa zvisina kuomeswa mushure mekugeza, uye mhando yechigadzirwa inoramba isingachinji mukuomesa uye granulation process.

1.3 X-ray diffraction analysis

X-ray diffraction analysis yakaitwa neRigaku D / max-3A X-ray diffractometer, graphite monochromator, Θ Angle yaiva 8 ° ~ 30 °, CuKα ray, tube pressure uye tube flow yaiva 30kV uye 30mA.

1.4 Infrared spectrum analysis

Spectrum-2000PE FTIR infrared spectrometer yakashandiswa kuongorora infrared spectrum. Ese masampuli ekuongorora infrared spectrum aive nehuremu hwe0.0020g. Aya masampuli akasanganiswa ne0.1600g KBr, zvichiteerana, uye ndokutsikirirwa (nehupamhi hwe <0.8mm) uye akaongororwa.

1.5 Kuonekwa kwekufambisa

Iyo transmittance yakaonekwa ne721 spectrophotometer. CMC mhinduro w=w1% yakaiswa mu1cm colorimetric dish pa590nm wavelength.

1.6 Dhigirii yekutsiva yekuona

Iyo HEC yekutsiva dhigirii yehydroxyethyl cellulose yakayerwa neyakajairwa kemikari yekuongorora nzira. Nheyo ndeyokuti HEC inogona kuderedzwa neHI hydroiodate pa123 ℃, uye dhigirii yekutsiviwa kweHEC inogona kuzivikanwa nekuyera zvinhu zvakaora ethylene uye ethylene iodide inogadzirwa. Iyo dhigirii yekutsiva yehydroxymethyl cellulose inogona zvakare kuyedzwa neyakajairwa makemikari ekuongorora nzira.

2. Migumisiro uye nhaurirano

Mhando mbiri dzekuita keturu dzinoshandiswa pano: imwe ndeyekukanya muchina sedhisheni yekuita, imwe iri kubvongodza rudzi rwekuita kettle seyekuita midziyo, mune heterogeneous reaction system, alkaline mamiriro uye doro remvura inonyungudutsa system, etherification reaction yeyakanatswa donje cellulose inodzidzwa. Pakati pazvo, hunyanzvi hwetekinoroji yemuchina wekukanya semidziyo yekuita ndeiyi: Mukuita, kukurumidza kweruoko rwekukanya kunononoka, nguva yekuita yakareba, chikamu chemaitiro eparutivi chakakwira, chiyero chekushandisa cheetherifying agent yakaderera, uye kufanana kwekutsiva kugovera kweboka mukuita kwe etherizing hakuna kunaka. Maitiro ekutsvagisa anogona kungogumira kune yakamanikana kuita mamiriro. Pamusoro pezvo, kurongeka uye kudzoreka kwemamiriro makuru ekuita (seyeyero yekugezera, alkali concentration, kukanya ruoko kumhanya kwemuchina wekukanya) kwakashata zvakanyanya. Zvakaoma kuwana kuenzana kwakafanana kwe etherification reaction uye kudzidza mafambisirwo akawanda uye kupinda kwe etherification reaction process mukudzika. Mamiriro ekuita anosimudzira reactor seyekuita midziyo ndeiyi: kukurumidza kumhanyisa kumhanya mukuita, kukurumidza kuita kukurumidza, yakanyanya kushandiswa mwero we etherizing agent, yunifomu yekugovera etherizing substituents, inogadziriswa uye inodzoreka main reaction mamiriro.

Carboxymethyl cellulose CMC yakagadzirwa nekneader reaction midziyo uye inosimudzira reactor reaction michina zvichiteerana. Apo kneader yakashandiswa sechigadziriso chekugadzirisa, simba rinokurudzira rakanga rakaderera uye avhareji yekutenderera kumhanya yaive 50r/min. Apo iyo inosimudzira reactor yakashandiswa seyekugadzirisa midziyo, iyo inosimudzira simba yaive yakakwirira uye avhareji yekutenderera kumhanya yaive 500r/min. Kana iyo molar ratio ye monochloroacetic acid kune cellulose monosaccharide yaive 1: 5: 1, nguva yekuita yaive 1.5h pa68 ℃. Kufambiswa kwemwenje kweCMC yakawanikwa nemuchina wekukanya yaive 98.02% uye kugona kweetherification kwaive 72% nekuda kwekunaka kweCM muchloroacetic acid etherifying agent. Kana iyo inobvongodza yakashandiswa semidziyo yekuita, kupenya kweiyo etherifying agent yaive nani, transmittance yeCMC yaive 99.56%, uye etherizing reaction inoshanda yakawedzera kusvika 81%.

Hydroxyethyl cellulose HEC yakagadzirirwa nekneader uye inosimudzira reactor semidziyo yekuita. Kana kneader yaishandiswa semidziyo yekuita, kuita kwekuita kwe etherizing agent yaive 47% uye kunyungudika kwemvura kwaive kwakashata apo kupenya kwechloroethyl alcohol etherizing agent kwaive kwakashata uye molar ratio ye chloroethanol kune cellulose monosaccharide yaive 3:1 pa60 ℃ kwe4h. . Chete kana iyo molar ratio ye chloroethanol kune cellulose monosaccharides iri 6: 1, izvo zvigadzirwa zvine kunaka kunyungudika kwemvura zvinogona kuumbwa. Kana iyo inosimudzira reactor yakashandiswa seyekuita midziyo, iyo permeability ye chloroethyl doro etherification agent yakava nani pa 68 ℃ kwe 4h. Kana iyo molar ratio ye chloroethanol kune cellulose monosaccharide yaive 3: 1, iyo yakaguma HEC yakave nekunyungudika kwemvura kuri nani, uye etherification reaction inoshanda yakawedzera kusvika 66%.

Mabatiro ekuita uye kukurumidza kwekuita kwe etherizing agent chloroacetic acid yakakwira zvakanyanya kupfuura iyo yechloroethanol, uye inosimudzira reactor se etherizing reaction midziyo ine mabhenefiti ari pachena pamusoro pe kneader, iyo inovandudza zvakanyanya etherizing reaction inoshanda. Iyo yakanyanya kutapurirana yeCMC inoratidzawo zvisina kunanga kuti inosimudzira reactor se etherizing reaction michina inogona kuvandudza homogeneity ye etherizing reaction. Izvi zvinodaro nekuti cheni ye cellulose ine mapoka matatu ehydroxyl pane yega yega glucose-boka mhete, uye chete munzvimbo yakazvimba zvakanyanya kana yakanyungudika ndipo ese ese e cellulose hydroxyl pairs etherifying agent mamorekuru anosvikika. Iyo etherification reaction ye cellulose inowanzoita heterogeneous reaction kubva kunze kuenda mukati, kunyanya munharaunda yecrystalline ye cellulose. Kana iyo crystal chimiro che cellulose chinoramba chakasimba pasina mhedzisiro yekunze kwesimba, etherifying agent yakaoma kupinda mu crystalline chimiro, inokanganisa homogeneity ye heterogeneous reaction. Nokudaro, nekugadzirisa jira rakanatswa (zvakadai sekuwedzera nzvimbo chaiyo yekotoni yakanatswa), reactivity yekotoni yakanatswa inogona kuvandudzwa. Muchikamu chikuru chekugezesa (ethanol / cellulose kana isopropyl doro / cellulose uye yakakwirira-yekukurumidza inokurudzira kuita, maererano nekufunga, kurongeka kwe cellulose crystallization zone kuchaderedzwa, panguva ino cellulose inogona kuzvimba zvakasimba, kuitira kuti kuzvimba. yeamorphous uye crystalline cellulose zone inowanzoenderana, Nokudaro, reactivity yeamorphous region uye crystalline region yakafanana.

Nekuburikidza nekuongorora infrared spectrum uye X-ray diffraction ongororo, iyo etherification reaction process ye cellulose inogona kunzwisiswa zvakanyanya kana inosimudzira reactor inoshandiswa se etherification reaction midziyo.

Pano, infrared spectra uye X-ray diffraction spectra zvakaongororwa. Iyo etherification reaction yeCMC neHEC yakaitwa mune yakamutswa reactor pasi pemamiriro ekuita anotsanangurwa pamusoro apa.

Iyo infrared spectrum analysis inoratidza kuti etheration reaction yeCMC neHEC inoshanduka nguva dzose nekuwedzera kwekuita nguva, dhigirii yekutsiva yakasiyana.

Kuburikidza nekuongororwa kweX-ray diffraction pateni, kujeka kweCMC neHEC kunosvika zero nekuwedzera kwekuita nguva, zvichiratidza kuti iyo decrystallization process yakanyatso kuitika muchikamu chealkalization uye nhanho yekudziya isati yaitwa etherification yedonje rakanatswa. . Naizvozvo, iyo carboxymethyl uye hydroxyethyl etherification reactivity yedonje rakanatswa haichanyanya kurambidzwa nekristaro yedonje rakanatswa. Izvo zvine hukama nepermeability ye etherifying agent. Zvinogona kuratidzwa kuti etherification reaction yeCMC neHEC inoitwa nekukurudzira reactor seyekuita midziyo. Pasi pekumhanya kukuru kubvongodza, zvinobatsira ku decrystallization process yedonje rakanatswa muchikamu chealkalization uye nhanho yekudziya isati yaita etherification reaction, uye inobatsira iyo etherification agent kuti ipinde mu cellulose, kuitira kuti ivandudze etherification reaction kunyatsoshanda uye kutsiva kufanana. .

Mukupedzisa, chidzidzo ichi chinosimbisa pesvedzero yesimba rinokurudzira uye zvimwe zvinhu pakuita kwakanaka panguva yekuita maitiro. Naizvozvo, chikumbiro chechidzidzo ichi chakavakirwa pazvikonzero zvinotevera: Muiyo heterogeneous etheration reaction system, kushandiswa kweyeshishi yakakura yekugezera uye yakakwirira inosimudzira kusimba, zvichingodaro, ndiyo mamiriro ekutanga ekugadzirira kweinenge homogeneous cellulose ether neboka rinotsiva. distribution; Mune chaiyo heterogeneous etheration reaction system, high performance cellulose ether ine ingangoita yunifomu kugovera kwezvinotsiva inogona kugadzirwa nekushandisa inosimudzira reactor seyekuita midziyo, izvo zvinoratidza kuti cellulose ether aqueous solution ine yakakwira transmittance, iyo yakakosha zvikuru kuwedzera zvivakwa. uye mabasa e cellulose ether. Muchina wekukanya unoshandiswa sechigadzirwa chekuita kudzidza etherification reaction yedonje rakanatswa. Nekuda kweiyo yakaderera kunyandura kusimba, haina kunaka kupinza kwe etherification agent, uye ine zvimwe zvayakaipira senge chikamu chepamusoro chemaitiro epadivi uye kushomeka kwekugovera kufanana kweetherification substituents.