I-Hydroxyethyl methyl cellulose (HEMC) iyi-ether ye-cellulose engeyona i-ionic esetshenziswa kakhulu ekwakheni, ekubaleni, e-ceramics, imithi, ukudla nezinye izimboni. I-HEMC inokuncibilika okuhle kwamanzi, ukuqina, ukugcinwa kwamanzi, ukwakheka kwefilimu kanye nezakhiwo zokubopha, futhi idlala indima ebalulekile odakeni oluxutshwe owomile, upende we-latex, okokuhlanza nezinye izinkambu.
1. Inqubo yokukhiqiza
1.1 Ukulungiselela impahla eluhlaza
I-HEMC ilungiswa kakhulu nge-cellulose yezitshalo zemvelo, i-methyl chloride (CH₃Cl), i-ethylene oxide (C₂H₄O), i-sodium hydroxide (NaOH) nezinye izinto zokusetshenziswa.
I-Cellulose: I-pulp yezinkuni noma i-cotton pulp ivame ukusetshenziswa njengempahla eluhlaza eyinhloko, edinga ukuhlanzeka okuphezulu kanye nokungcola okumbalwa ukuze kuqinisekiswe ikhwalithi yomkhiqizo.
I-Alkalizer (NaOH): isetshenziselwa ukwenza i-cellulose isebenze futhi ithuthukise umsebenzi wokusabela.
Umenzeli we-Etherifying (CH₃Cl futhi C₂H₄O): hlinzeka ngamaqembu e-methyl kanye ne-hydroxyethyl ngokulandelana, ukuze i-cellulose ibhekane nokusabela esikhundleni, ithuthukise ukuncibilika kwamanzi kanye nezakhiwo zokusebenza.
I-solvent ye-Organic (njenge-isopropanol): isetshenziselwa ukuncibilikisa ama-reactants, ukulawula indawo yokusabela kanye nokunciphisa ukusabela ohlangothini.
1.2 Ukwelashwa kwe-alkalization
Ngemuva kokuchotshozwa kwe-cellulose, inani elifanele lesisombululo se-sodium hydroxide liyengezwa futhi ukwelashwa kwe-alkalization kwenziwa ekushiseni okuthile nokucindezela, okuvame ukuthatha imizuzu engu-30-60. Inhloso eyinhloko ye-alkalization ukukhulisa iketango lamangqamuzana e-cellulose futhi kuthuthukiswe ukusebenza kabusha kwayo ne-ejenti e-etherifying. Le nqubo ivamise ukwenziwa kureactor evaliwe ngokunyakazisa ukuze kuqinisekiswe ukuthi isisombululo se-alkali singena ngokulinganayo ku-cellulose.
1.3 Ukusabela kwe-Etherification
I-alkalized cellulose isabela nge-methylation kanye nama-hydroxyethylation reagents (CH₃Cl futhi C₂H₄O) kureactor ukukhiqiza i-hydroxyethyl methyl cellulose. Izimo zokusabela zihlanganisa:
Izinga lokushisa: 60-90°C
Ingcindezi: 0.5-1.5 MPa
Isikhathi: amahora angu-2-5
Ngesikhathi sokuphendula, ukusabela kwe-methylation kanye ne-hydroxyethylation kuqhubeka kanyekanye, ukuze ingxenye ye-hydroxyl (-OH) ye-cellulose ithathelwe indawo yi-methyl (-OCH).₃) kanye ne-hydroxyethyl (-OCH₂CH₂OH), ngaleyo ndlela ishintsha izakhiwo zayo zokuncibilika nokujiya. Ukuze kuthuthukiswe izinga lokushintsha (amavelu e-DS kanye ne-MS), ngokuvamile kuyadingeka ukuthuthukisa ukuhleleka nengxenye yokwengezwa kwe-etherification.
1.4 Ukungathathi hlangothi nokugeza
Ngemuva kokuthi ukusabela kuqediwe, isistimu isaqukethe i-alkali engaphenduliwe, i-solvent kanye nemikhiqizo (njenge-NaCl). Ngakho-ke, ukungathathi hlangothi nokugeza kuyadingeka:
I-Neutralization: Sebenzisa i-asidi (efana ne-acetic acid) ukuze unciphise i-alkali ohlelweni futhi ulungise inani le-pH libe ngu-6-8.
Ukugeza: Sebenzisa inani elikhulu lamanzi ashisayo noma i-ethanol aqueous solution ukugeza kaningi i-cellulose ukuze ukhiphe izinto ezingaphenduliwe kanye nemikhiqizo ekhiqizwe, unciphise ukungcola, futhi uthuthukise ukuhlanzeka komkhiqizo.
1.5 Ukomisa nokuchoboza
Ngemuva kokugeza, i-HEMC isaqukethe umswakama ophezulu futhi idinga ukomiswa. Izindlela zokomisa ezijwayelekile yilezi:
Ukomisa ukugeleza komoya: kusetshenziswa umoya oshisayo onesivinini esikhulu ukomisa i-HEMC emanzi, ngokusebenza kahle okuphezulu futhi kulungele ukukhiqizwa kwezinga elikhulu.
Ukomiswa kwe-vacuum: ukushisa nokomisa ngaphansi kwemvelo yengcindezi ephansi, engavimbela ngempumelelo ukuwohloka kwe-cellulose futhi ifanele imikhiqizo yekhwalithi ephezulu.
Ngemuva kokumisa, i-HEMC ichotshozwa yi-pulverizer futhi usayizi wezinhlayiyana ulawulwa ngokuhlolwa ukuze kuzuzwe ubuhle obudingekayo bomkhiqizo (ngokuvamile i-80-120 mesh).
2. Ukulawulwa kwekhwalithi
Ukulawulwa kwekhwalithi ye-HEMC ikakhulukazi kufaka phakathi izinkomba ezilandelayo:
IDegree of substitution (DS kanye ne-MS): inquma ukunyibilika kanye ne-viscosity, ngokuvamile i-DS iphakathi kuka-1.1-2.0 futhi i-MS iphakathi kuka-0.1-0.5.
Okuqukethwe komswakama: ngokuvamile kuyadingeka ukuba kube≤5%.
I-Viscosity: amabanga ahlukene e-viscosity ayadingeka ezinkambini zezicelo ezahlukahlukene (ezifana ne-400-100,000 mPa·s).
Ukuhlanzeka: kudinga okuqukethwe komlotha okuphansi, ukususwa kwezincibilikitsi ezisalelayo, nokuqinisekisa ukuthi akukho phunga.
3. Izindawo zokufaka izicelo eziyinhloko
Izinto zokwakha: ezisetshenziselwa udaka lukasimende, i-putty powder, i-adhesive tile, ukuthuthukisa ukugcinwa kwamanzi nokusebenza kokwakhiwa.
Imboni yokumboza: isetshenziswa ngopende we-latex nopende, ukuhlinzeka nge-rheology enhle nokusebenza okulwa nokuwohloka.
Umuthi nokudla: njenge-thickener ne-emulsifier, ngokuhambisana nebanga lokudla noma amazinga e-pharmacopoeia.
II-HEMC inqubo yokukhiqiza ihlanganisa alkalization, etherification, neutralization, ukuwasha, omiswe kanye nokuchotshozwa. Ukuthuthukisa amapharamitha wenqubo nokuthuthukisa idigri yokushintsha kanye nokuhlanzeka komkhiqizo izihluthulelo zokuthuthukisa ukusebenza kwe-HEMC. Ngezidingo ezikhulayo zokuvikelwa kwemvelo kanye nokukhiqizwa okuluhlaza, ukukhiqizwa kwe-HEMC kuzonaka kakhulu ukongiwa kwamandla kanye nokunciphisa ukukhishwa kwe-emission kanye nokusetshenziswa kwezincibilikisi eziluhlaza esikhathini esizayo.
Isikhathi sokuthumela: May-08-2025