Hydroxyethyl cellulose (HEC) isiri-ionic, mvura-inonyungudika polima inotorwa kubva ku cellulose, yakasikwa polima inowanikwa musero madziro emiti. Inoshandiswa zvakanyanya mumaindasitiri akasiyana siyana, anosanganisira emishonga, zvizorwa, pendi, uye zvinonamira, nekuda kwekukora kwayo, kugadzira firimu, uye rheological properties. Kugadzirira kwehydroxyethyl cellulose kunosanganisira etherification ye cellulose ne ethylene oxide pasi pemamiriro ealkaline. Iyi nzira inogona kukamurwa kuita akati wandei matanho akakosha: kucheneswa kweselulosi, alkalization, etherification, neutralization, kuwacha, uye kuomesa.
1. Cellulose Kucheneswa
Nhanho yekutanga mukugadzirira kwehydroxyethyl cellulose kucheneswa kweselulosi, kazhinji inotorwa kubva pahuni pulp kana machira ekotoni. Raw cellulose ine tsvina yakaita se lignin, hemicellulose, uye zvimwe zvinobviswa zvinofanirwa kubviswa kuti zviwane high-purity cellulose inokodzera kugadziriswa kwemakemikari.
Matanho anobatanidzwa:
Mechanical Processing: Iyo mbishi cellulose inogadzirwa nemuchina kuti ideredze saizi yayo uye kuwedzera nzvimbo yayo, kufambisa kunotevera kurapwa kwemakemikari.
Kemikari Kurapa: Iyo cellulose inobatwa nemakemikari akadai sodium hydroxide (NaOH) uye sodium sulfite (Na2SO3) kuti iparadze lignin uye hemicellulose, inoteverwa nekugeza uye bleaching kubvisa tsvina yakasara uye kuwana chena, fibrous cellulose.
2. Alkalization
Iyo yakacheneswa cellulose inozogadziriswa kuti iite kuti iite etherification reaction. Izvi zvinosanganisira kurapa cellulose ine aqueous solution ye sodium hydroxide.
Mhinduro:
Cellulose+NaOH→Alkali cellulose
Maitiro:
Iyo cellulose inomiswa mumvura, uye sodium hydroxide solution inowedzerwa. Iko kusangana kweNaOH kunowanzo kubva pa10-30%, uye maitiro anoitwa patembiricha iri pakati pe20-40 ° C.
Musanganiswa unomutswa kuti uve nechokwadi chekutorwa kweiyo alkali, zvichitungamira pakuumbwa kwealkali cellulose. Iyi yepakati inonyanya kuita react kune ethylene oxide, kufambisa iyo etherification maitiro.
3. Etherification
Nhanho yakakosha mukugadzirira kwehydroxyethyl cellulose ndeye etherification yealkali cellulose ine ethylene oxide. Izvi zvinounza hydroxyethyl mapoka (-CH2CH2OH) mumusana we cellulose, zvichiita kuti inyungudika nemvura.
Mhinduro:
Alkali cellulose+Ethylene oxide→Hydroxyethyl cellulose+NaOH
Maitiro:
Ethylene oxide inowedzerwa kune alkali cellulose, ingave iri mubatch kana inoenderera. Maitiro acho anowanzo itwa mune autoclave kana pressure reactor.
Mamiriro ekuita, anosanganisira tembiricha (50-100 ° C) uye kudzvanywa (1-5 atm), anodzorwa nekuchenjera kuti ave nechokwadi chekutsiva kwakaringana kwemapoka ehydroxyethyl. Iyo dhigirii yekutsiva (DS) uye molar substitution (MS) yakakosha paramita inopesvedzera zvimiro zvechigadzirwa chekupedzisira.
4. Neutralization
Mushure mekuita etherification, musanganiswa une hydroxyethyl cellulose uye yakasara sodium hydroxide. Nhanho inotevera ndeyekusarerekera, uko iyo yakawandisa alkali inoderedzwa uchishandisa asidhi, kazhinji acetic acid (CH3COOH) kana hydrochloric acid (HCl).
Mhinduro:NaOH+HCl→NaCl+H2O
Maitiro:
Iyo asidhi inowedzerwa zvishoma nezvishoma kumusanganiswa wekuita pasi pemamiriro akadzorwa kudzivirira kupisa kwakanyanya uye kudzivirira kuderedzwa kwehydroxyethyl cellulose.
Musanganiswa wakasiiwa unobva waiswa pasi pekugadziriswa kwepH kuti ive mukati meiyo yaidiwa renji, kazhinji yakatenderedza kwayakarerekera pH (6-8).
5. Kugeza
Kutevera neutralization, chigadzirwa chinofanira kushambidzwa kubvisa munyu uye zvimwe zvigadzirwa. Iyi nhanho yakakosha pakuwana yakachena hydroxyethyl cellulose.
Maitiro:
Iyo reaction musanganiswa inonatswa nemvura, uye iyo hydroxyethyl cellulose inoparadzaniswa nekusefa kana centrifugation.
Iyo yakaparadzaniswa yehydroxyethyl cellulose inoshambidzwa kakawanda nemvura yakasvibiswa kuti ibvise munyu wakasara uye tsvina. Nzira yekugeza inoenderera mberi kusvikira mvura yekugeza inosvika kune yakananga conductivity, ichiratidza kubviswa kwetsvina inonyungudika.
6. Kuomesa
Nhanho yekupedzisira mukugadzirira kwehydroxyethyl cellulose iri kuomesa. Iyi nhanho inobvisa mvura yakawandisa, ichipa chigadzirwa chakaoma, cheupfu chakakodzera kushandiswa kwakasiyana-siyana.
Maitiro:
Iyo yakagezwa hydroxyethyl cellulose inowaridzwa pamatireyi ekuomesa kana kufambiswa nemugero wekuomesa. Iyo tembiricha yekuomesa inodzorwa nekuchenjerera kudzivirira kusvibiswa kwemafuta, kazhinji kubva pa50-80 ° C.
Neimwe nzira, kupfapfaidza kuomeswa kunogona kushandiswa kuomesa nekukurumidza. Mukupfapfaidza kuomesa, iyo aqueous hydroxyethyl cellulose mhinduro inoiswa atomi kuita madonhwe akanaka uye yakaomeswa mumhepo inopisa, zvichikonzera hupfu hwakatsetseka.
Chigadzirwa chakaomeswa chinobva chagayiwa kusvika pakukura kwechidimbu chaidiwa uye kurongedzerwa kuchengetwa nekugovaniswa.
Kudzora Hunhu uye Zvishandiso
Munguva yese yekugadzirira, akaomesesa emhando yekudzora matanho anoitwa kuti ave nechokwadi chekuenderana uye mhando yehydroxyethyl cellulose. Makiyi ma paramita akadai se viscosity, dhigirii rekutsiva, hunyoro hwemukati, uye saizi yechikamu inogara ichitariswa.
Applications:
Pharmaceuticals: Inoshandiswa seyakakora mumiriri, binder, uye stabilizer mumigadziriso semapiritsi, kumiswa, uye mafuta ekuzora.
Cosmetics: Inopa viscosity uye magadzirirwo kune zvigadzirwa zvakaita semafuta, lotions, uye shampoos.
Paints uye Coatings: Inoita seyakakora uye rheology modifier, inovandudza zvivakwa zvekushandisa uye kugadzikana kwependi.
Indasitiri Yezvekudya: Inoshanda seyakakora, stabilizer, uye emulsifier muzvigadzirwa zvakasiyana siyana zvekudya.
Kugadzirira kwehydroxyethyl cellulose kunosanganisira akateedzana akanyatsotsanangurwa kemikemikari nemakanika maitiro ane chinangwa chekugadzirisa cellulose kuunza hydroxyethyl mapoka. Nhanho imwe neimwe, kubva pakucheneswa kweselulosi kusvika pakuomeswa, yakakosha pakuona kunaka uye kushanda kwechigadzirwa chekupedzisira. Hydroxyethyl cellulose's versatile properties inoita kuti ive chinhu chakakosha mumaindasitiri akawanda, zvichiratidza kukosha kwemaitiro chaiwo ekugadzira kuti asangane nezvinodiwa zvekushandisa kwakasiyana.
Nguva yekutumira: May-28-2024