Iyiphi inqubo yokukhiqiza ye-methylcellulose?

I-methylcellulose (MC) iyingxenye ye-polymer esetshenziswa ngamanzi esetshenziswa kabanzi ekudleni, emithini, amakhemikhali nsuku zonke, ezokwakha kanye nezinye izimboni. Inqubo yayo yokukhiqiza ifaka izinyathelo eziningi, ikakhulukazi kufaka phakathi ukukhishwa kwe-cellulose, ukuguqulwa ukuguqulwa, ukomisa nokuchoboza.

1. Ukukhishwa kwe-cellulose
Izinto ezisetshenziswayo eziyisisekelo ze-methylcellulose ziyi-cellulose yemvelo, evame ukususelwa epulpini lezinkuni noma ukotini. Okokuqala, izinkuni noma ukotini kufakwa ngaphansi kochungechunge lokususa ukungcola (njenge-lignin, resin, amaprotheni, njll.) Ukuthola iselula emsulwa. Izindlela ezejwayelekile zokuhlekisa zifaka indlela ye-acid-base kanye nendlela ye-enzymatic. Endleleni ye-acid-base, u-soulp noma ukotini i-pulp iphathwa nge-sodium hydroxide (Naoh) noma ezinye izixazululo ze-alkali ukuncibilikisa ubumbano nokunye ukungcola, ngaleyo ndlela kukhishwe i-cellulose.

2. Ukusabela kokuthembela kwe-cellulose
Okulandelayo, ukusabela kwe-methylation (ukusabela kokuthezeka) kwenziwa ukulungiselela i-methylcellulose. Isinyathelo esiyisisekelo sokuphendula ukusheshisa ukusabela kuselula nge-methylating ejenti (imvamisa i-methyl chloride, i-methyl iodide, njll.) Ukuthola i-methylcellulose. Ukusebenza okuthize kungokulandelayo:

Ukukhetha kwe-solvent yokusabela: ama-solvents we-polar (njengamanzi, i-ethanol noma i-solvent exubile yamanzi notshwala) avame ukusetshenziswa njengemidiya yokuphendula, kanye ne-catalysts (njenge-sodium hydroxide) kwesinye isikhathi angezwe ukuthuthukisa ukusabela.
Izimo Zokuphendula: Ukusabela kwenziwa emazingeni okushisa athile nengcindezi, kanye nokushisa okujwayelekile kokuphendula ngu-50-70 ° C. Ngesikhathi sokuphendula, i-methyl chloride iphendula ngeqembu le-hydroxyl (-OH) e-cellulose molecule ukuzoliguqula kube yi-methyl cellulose.
Ukulawula Ukuphendula: Ukusabela kwe-methylation kudinga ukulawula okuqondile kwesikhathi sokuphendula kanye nokushisa. Isikhathi eside kakhulu sokuphendula noma izinga lokushisa eliphakeme kakhulu lingadala ukubola kweselula, ngenkathi izinga lokushisa eliphansi kakhulu noma ukuphendula okungaphelele kungaholela ekusebenzeni okunganele, okuthinta ukusebenza kwe-methyl cellulose.

3. Ukungathathi hlangothi nokuhlanza
Ngemuva kokuthi ukusabela sekuqediwe, ama-reagents we-methylation angavuliwe kanye nama-catalysts angahlala emkhiqizweni we-methyl cellulose, okudinga ukungathathi hlangothi futhi ahlanzwa. Inqubo yokungathathi hlangothi ivame ukusebenzisa isixazululo se-acidic (njenge-acetic acid solution) ukuze izuze izinto ze-alkali kuMkhiqizo wokuphendula. Inqubo yokuhlanza isebenzisa inani elikhulu lamanzi noma utshwala ukususa amakhemikhali, amakhemikhali angabhalisiwe kanye nemikhiqizo ngemuva kokuphendula ukuze aqinisekise ubumsulwa bomkhiqizo wokugcina.

4. Ukomisa nokuchoboza
Ngemuva kokugeza, i-methylcellose imvamisa isesimweni sokunamathisela noma sejeli, ngakho-ke kudinga ukomiswa ukuthola umkhiqizo oluyimpuphu. Kunezindlela eziningi zoma, futhi ezisetshenziswayo ezivame ukusetshenziswa zifaka ukomisa isifutho, ukumisa ukomisa nokomisa kwe-vacuum. Ngesikhathi senqubo yokomisa, izinga lokushisa nomswakama kudingeka lilawulwe ngokuqinile ukuze ligweme ukubola okubangelwa ukushisa okuphezulu noma ukulimala kwezindawo ze-gel.

Ngemuva kokumiswa, i-methylcellose etholakele idinga ukuchotshozwa ukufeza usayizi wezinhlayiyana ezidingekayo. Inqubo yokuchotshozwa ivame ukuqedwa yi-Air jet get milling noma milling mehendi. Ngokulawula usayizi wezinhlayiyana, izinga lokuchithwa kanye nezimpawu ze-viscosity ze-methylcellulose zingalungiswa.

5. Ukuhlola kanye nokupakishwa komkhiqizo wokugcina
Ngemuva kokuchotshozwa, i-methylcellose idinga ukubhekana nokulawulwa kwekhwalithi okuqinile ukuqinisekisa ukuthi ihlangabezana nokucaciswa kobuchwepheshe. Izinto zokuhlola ezivamile zifaka:

Okuqukethwe umswakama: okuqukethwe okuphezulu kakhulu komswakama we-methylcellulose kuzothinta ukuqina nokugcinwa kwayo.
Ukusatshalaliswa kosayizi wezinhlayiyana: Usayizi nokusatshalaliswa kwezinhlayiya kuzothinta i-solubity ye-methylcellulose.
I-degree of methylation: Izinga le-methylation liyisikhombi esikhulu sokuhlola ikhwalithi ye-methylcellulose, ethinta ukusebenza kwayo kanye nokusebenza kohlelo lokusebenza.
I-Solubity kanye ne-Viscosity: I-solubility kanye nokubonakala kwe-methylcellose kungamapharamitha abalulekile ekusetshenzisweni kwawo, ikakhulukazi emkhakheni wokudla nomuthi.
Ngemuva kokudlula ekuhlolweni, umkhiqizo uzohlanganiswa ngokuya ngezidingo ezihlukile, imvamisa ezikhwameni zepulasitiki noma ezikhwameni zephepha, futhi kumakwe ngenombolo ye-batch yokukhiqiza, imininingwane, usuku lokukhiqiza kanye neminye imininingwane.

6. Ukuvikelwa kwezemvelo nokuphepha
Ngesikhathi senqubo yokukhiqiza ye-methyl cellulose, izindlela ezifanele zokuvikela ezemvelo zidinga ukuthathwa, ikakhulukazi amakhemikhali nama-sol asetshenziswa kwinqubo yokusabela. Ngemuva kokuphendula, imfucumfucu kanye negesi yokungcola kufanele iphathwe ukuze uvikele ukungcolisa imvelo. Ngaphezu kwalokho, ama-reagents wamakhemikhali kwinqubo yokukhiqiza kufanele asebenze ngokuqinile ngezinqubo zokusebenza zokuphepha ukuze aqinisekise ukuphepha kwabasebenzi.

Inqubo yokukhiqiza ye-methyl cellulose ifaka ikakhulukazi ukukhishwa kwe-cellulose, ukusabela kwe-methylation, ukugeza nokungathathi hlangothi, ukomisa nokuchoboza. Isixhumanisi ngasinye sinomthelela obalulekile kwikhwalithi yomkhiqizo wokugcina, ngakho-ke ukulawula nokuqapha inqubo yokukhiqiza kubalulekile kakhulu. Ngalezi zinyathelo zenqubo, i-methyl cellulose ehlangabezana nezidingo zohlelo lokusebenza ezihlukile ingakhiqizwa.