IHydroxyethyl methyl Iselulosi

I-Cellulose ether yimathiriyeli ye-polymer entle esetyenziswa kakhulu eyenziwe kwi-cellulose yendalo yepolymer ngonyango lwekhemikhali. Emva kokwenziwa kwe-cellulose nitrate kunye ne-cellulose acetate ngenkulungwane ye-19, iikhemisti ziye zavelisa uthotho lwee-cellulose derivatives ze-cellulose ethers ezininzi, kwaye iindawo ezintsha zokusetyenziswa ziye zafunyanwa ngokuqhubekayo, ezibandakanya amacandelo amaninzi amashishini. Iimveliso ze-cellulose ether ezifana ne-sodium carboxymethyl cellulose (CMC), i-ethyl cellulose (EC), i-hydroxyethyl cellulose (HEC), i-hydroxypropyl cellulose (HPC), i-methyl hydroxyethyl cellulose (MHEC) kunye ne-methyl hydroxypropyl cellulose (MHPC) kunye nezinye i-cellulose ethers zaziwa ngokuba "industrial monosodium glutamate" kwaye isetyenziswe ngokubanzi kwi-oyile yokugaya, ukwakhiwa, iingubo, ukutya, amayeza kunye neekhemikhali zemihla ngemihla.

I-Hydroxyethyl methylcellulose(MHEC) i-odorless, incasa, i-powder emhlophe engekho inetyhefu enokuthi inyibilike emanzini abandayo ukwenza isisombululo se-viscous esicacileyo. Ineempawu zokuqina, ukubopha, ukusabalalisa, i-emulsifying, ifilimu-ifom, ukumisa, i-adsorbing, i-gelling, i-surface esebenzayo, ukugcina umswakama kunye nokukhusela i-colloid. Ngenxa yomsebenzi osebenzayo womphezulu wesisombululo samanzi, sinokusetyenziswa njenge-colloidal arhente yokukhusela, i-emulsifier kunye ne-dispersant. I-Hydroxyethyl methylcellulose isisombululo samanzi sine-hydrophilicity elungileyo kwaye sisixhobo esisebenzayo sokugcina amanzi. Ngenxa yokuba i-hydroxyethyl methylcellulose iqukethe amaqela e-hydroxyethyl, inekhono elihle lokulwa nokukhunda, ukuzinza okuhle kwe-viscosity kunye nokumelana nokungunda ngexesha lokugcinwa kwexesha elide.

I-Hydroxyethyl methylcellulose (HEMC) ilungiselelwe ngokuzisa i-ethylene oxide substituents (MS 0.3 ~ 0.4) kwi-methylcellulose (MC), kwaye ukuxhathisa kwayo ityuwa kungcono kuneepolymers ezingaguqukiyo. Ubushushu be-gelation ye-methylcellulose bukwaphezulu kune-MC.

Ulwakhiwo:

Uphawu:

Iimpawu eziphambili ze-hydroxyethyl methylcellulose (HEMC) zezi:

1. Ukunyibilika: Ukunyibilika emanzini kunye nezinye izinyibilikisi eziphilayo. I-HEMC inokuchithwa emanzini abandayo. Ingqwalasela yayo ephezulu inqunywe kuphela yi-viscosity. Ukunyibilika kuyahluka kunye ne-viscosity. I-viscosity ephantsi, i-solubility enkulu.
2. Ukumelana netyuwa: Iimveliso ze-HEMC azikho i-ionic cellulose ethers kwaye azikho i-polyelectrolytes, ngoko ke zizinzile kwisisombululo se-aqueous xa iityuwa zetsimbi okanye i-electrolytes eziphilayo zikhona, kodwa ukongezwa ngokugqithiseleyo kwe-electrolytes kunokubangela i-gelation kunye nemvula.
3. Umsebenzi womphezulu: Ngenxa yomsebenzi osebenzayo wesisombululo samanzi, unokusetyenziswa njenge-agent ekhuselayo ye-colloidal, i-emulsifier kunye ne-dispersant.
4. Ijeli ye-Thermal: Xa isisombululo samanzi semveliso ye-HEMC sifudunyezwa kwiqondo lokushisa elithile, liba li-opaque, i-gel, kunye ne-precipitates, kodwa xa licolile ngokuqhubekayo, libuyela kwimeko yesisombululo sokuqala, kunye neqondo lokushisa apho le gel kunye nemvula. kwenzeka ikakhulu Kuxhomekeke kuzo izithambisi, izixhobo zokuxhoma, iicolloids ezikhuselayo, ii-emulsifiers njl.
5. I-Metabolism inert kunye nevumba eliphantsi kunye nevumba elimnandi: I-HEMC isetyenziswa kakhulu kukutya kunye namayeza ngenxa yokuba ayiyi kuxutywa kwaye inevumba eliphantsi kunye nevumba.
6. Ukunganyangeki kokungunda: I-HEMC inokumelana kakuhle nokungunda kunye nokuzinza okuhle kwe-viscosity ngexesha lokugcinwa kwexesha elide.
7. Ukuzinza kwe-PH: I-viscosity yesisombululo samanzi semveliso ye-HEMC ayinakuchaphazeleka nge-asidi okanye i-alkali, kwaye ixabiso le-pH lizinzile ngaphakathi kwinqanaba le-3.0 ukuya kwi-11.0.

Isicelo:

I-Hydroxyethyl methylcellulose ingasetyenziselwa njenge-agent ekhuselayo ye-colloidal, i-emulsifier kunye ne-dispersant ngenxa yomsebenzi wayo osebenza phezu komhlaba kwisisombululo samanzi. Imizekelo yokusetyenziswa kwayo yile ilandelayo:

1. Impembelelo ye-hydroxyethyl methylcellulose ekusebenzeni kwesamente. IHydroxyethyl methylcellulose ngumgubo omhlophe ongenavumba, ongenancasa, ongenatyhefu onokunyibilika emanzini abandayo ukwenza isisombululo se-viscous esicacileyo. Ineempawu zokuqina, ukubopha, ukusabalalisa, i-emulsifying, ifilimu-ifom, ukumisa, i-adsorbing, i-gelling, i-surface esebenzayo, ukugcina umswakama kunye nokukhusela i-colloid. Ekubeni isisombululo esinamanzi sinomsebenzi osebenzayo, sinokusetyenziswa njenge-colloidal arhente yokukhusela, i-emulsifier kunye ne-dispersant. I-Hydroxyethyl methylcellulose isisombululo samanzi sine-hydrophilicity elungileyo kwaye sisixhobo esisebenzayo sokugcina amanzi.
2. Ipeyinti yokunceda ene-flexibility ephezulu ilungiselelwe, eyenziwe ngezinto eziluhlaza ezilandelayo kwiingxenye ngobunzima: 150-200 g wamanzi adibeneyo; 60-70 g ye-emulsion ecocekileyo ye-acrylic; 550-650 g ye-calcium enzima; 70-90 g yomgubo we-talcum; I-30-40g yesiseko se-cellulose isisombululo samanzi; 10-20g lignocellulose isisombululo samanzi; I-4-6g yokuncedisa ifilimu; 1.5-2.5g i-antiseptic kunye ne-bactericide; 1.8-2.2g dispersant; 3.5-4.5g; I-ethylene glycol 9-11g; Isisombululo samanzi se-hydroxyethyl methylcellulose senziwe ngokuchithwa kwe-2-4% ye-hydroxyethyl methylcellulose emanzini; Isisombululo samanzi se-lignocellulose senziwe nge-1-3% I-Lignocellulose yenziwe ngokuchithwa emanzini.

Ukulungiselela:

Indlela yokulungiselela i-hydroxyethyl methylcellulose, indlela kukusebenzisa ikotoni ecocekileyo njengento eluhlaza kunye ne-ethylene oxide njenge-etherification agent yokulungisa i-hydroxyethyl methylcellulose. Izixhobo zobunzima bezinto eziluhlaza zokulungiselela i-hydroxyethyl methyl cellulose zimi ngolu hlobo lulandelayo: 700-800 iinxalenye ze-toluene kunye ne-isopropanol umxube njenge-solvent, i-30-40 iinxalenye zamanzi, i-70-80 ye-sodium hydroxide, i-80-85 i-cotton ecocekileyo; ring 20-28 iinxalenye oxyethane, 80-90 iinxalenye methyl chloride, 16-19 iinxalenye glacial acetic acid; Amanyathelo athile ngala:

Isinyathelo sokuqala, kwi-kettle yokusabela, yongeza i-toluene kunye ne-isopropanol umxube, amanzi, kunye ne-sodium hydroxide, ukushisa ukuya kwi-60-80 ° C, gcina ukufudumala imizuzu engama-20-40;

Isinyathelo sesibini, i-alkalization: zipholisa izinto ezingentla ukuya kwi-30-50 ° C, yongeza umqhaphu ococekileyo, utshize i-toluene kunye ne-isopropanol umxube we-solvent, uyimpompe kwi-0.006Mpa, ugcwalise i-nitrogen ngokutshintshwa kwe-3, kwaye uqhube emva kokutshintshwa kwe-Alkalinization. iimeko ze-alkalization zezi: ixesha le-alkalization liyi-2 iiyure, kwaye ukushisa kwe-alkalization yi-30 ° C ukuya ku-50 ° C;

Isinyathelo sesithathu, i-etherification: emva kokuba i-alkalization igqityiwe, i-reactor ikhutshwe kwi-0.05-0.07MPa, kwaye i-ethylene oxide kunye ne-methyl chloride yongezwa imizuzu engama-30-50; isigaba sokuqala se-etherification: 40-60 ° C, 1.0-2.0 Iiyure, uxinzelelo lulawulwa phakathi kwe-0.15 kunye ne-0.3Mpa; isigaba sesibini se-etherification: 60～90℃, 2.0～2.5 iiyure, uxinzelelo lulawulwa phakathi kwe-0.4 kunye ne-0.8Mpa;

Isinyathelo sesine, ukungathathi hlangothi: Yongeza i-acetic acid elinganisiweyo kwangaphambili kwi-kettle yemvula, cinezela kwi-etherified material for neutralization, ukunyusa ubushushu ukuya ku-75-80 ° C ukuze kube nemvula, ubushushu buphakama ukuya kwi-102 ° C, kunye ne-pH. ixabiso yi-6 Ngentsimbi yesi-8, i-desolventization igqityiwe; itanki ye-desolventization izaliswe ngamanzi epompo aphathwe ngesixhobo se-osmosis esibuyela emva kwi-90 ° C ukuya kwi-100 ° C;

Isinyathelo sesihlanu, ukuhlamba i-centrifugal: izinto eziphathekayo kwinqanaba lesine li-centrifuged ngokusebenzisa i-screw centrifuge ene-horizontal screw, kwaye izinto ezihlukeneyo zidluliselwa kwitanki yokuhlamba ezaliswe ngamanzi ashushu kwangaphambili ukuze kuhlanjwe izinto;

Isinyathelo sesithandathu, ukomiswa kwe-centrifugal: izinto ezihlanjiweyo zigqithiselwa kwi-dryer nge-screw centrifuge ene-horizontal screw, kwaye izinto zomiswe kwi-150-170 ° C, kwaye izinto ezomileyo zityunyuziwe kwaye zipakishwe.

Xa kuthelekiswa neteknoloji yokuvelisa i-cellulose ether ekhoyo, ukuveliswa kwangoku kusebenzisa i-ethylene oxide njenge-etherification agent ukuze kulungiswe i-hydroxyethyl methyl cellulose, enekhono elihle lokulwa nokubunjwa ngenxa yokuqulatha amaqela e-hydroxyethyl. Inozinzo oluhle lwe-viscosity kunye nokumelana nokubola ngexesha lokugcinwa kwexesha elide. Ingasetyenziswa endaweni yezinye ii-cellulose ethers.