Cellulose ether ni polymer ikoze muri cellulose karemano nk'ibikoresho fatizo binyuze mu guhindura shimi. Cellulose ether ni ikintu gikomoka kuri cellulose karemano, ikorwa rya cellulose ether na polymer ikoze muri synthetic ni bitandukanye, ibikoresho byayo by'ibanze ni cellulose, ibintu bisanzwe bya polymer. Bitewe n'imiterere ya cellulose karemano, cellulose ubwayo ntabwo ifite ubushobozi bwo gukorana n'ikintu gitanga ether. Ariko nyuma yo kuvurwa ikintu gitanga ether, imigozi ikomeye ya hydrogen hagati y'iminyururu ya molekile n'iminyururu yarangiritse, maze imikorere ya hydroxyl group yarekuwe muri alkali cellulose ifite ubushobozi bwo gukora reaction, maze cellulose ether yaboneka binyuze mu gukora reaction ya etherifying agent - OH group muri - OR group.
Imiterere ya eteri za selulosi iterwa n'ubwoko, umubare n'uburyo ibintu bisimburana bikwirakwira. Uburyo eteri ya selulosi ishyirwa mu byiciro bushingiye kandi ku bwoko bw'ibintu bisimburana, urwego rwa eteri, gushonga no gukoreshwa bifitanye isano bishobora gushyirwa mu byiciro. Dukurikije ubwoko bw'ibintu bisimburana ku ruhererekane rwa molekile, ishobora kugabanywamo eteri imwe na eteri ivanze. MC ikoreshwa nk'eteri imwe, mu gihe HPmc ari eteri ivanze. Methyl cellulose ether MC ni igice cy’isukari karemano cya selulosi kuri hydroxyl ni methooxide yasimbuwe na formula y’imiterere y’ibicuruzwa [CO H7O2 (OH) 3-H (OCH3) H] X, hydroxypropyl methyl cellulose ether HPmc ni igice kiri kuri hydroxyl ni igice cya methooxide yasimbuwe, ikindi gice cy’ibicuruzwa byasimbuwe na hydroxypropyl, Formula y’imiterere ni [C6H7O2 (OH) 3-MN (OCH3) M [OCH2CH (OH) CH3] N] X na hydroxyethyl methyl cellulose ether HEmc, ikoreshwa cyane kandi igurishwa ku isoko.
Kuva ku gushonga bishobora kugabanywamo ubwoko bwa ionic n'ubwoko butarimo ionic. I-cellulose eteri ishongeshwa mu mazi igizwe ahanini na alkyl ether na hydroxyl alkyl ether y'ubwoko bubiri. Ionic Cmc ikoreshwa cyane cyane mu isabune y'ubukorikori, imyenda, icapiro, ibiryo no mu icukurwa rya peteroli. I-MC idashingiye kuri ionic, HPmc, HEmc n'izindi zikoreshwa cyane cyane mu bikoresho by'ubwubatsi, irangi rya latex, ubuvuzi, shimi ya buri munsi n'ibindi. Nk'ikintu gikomeza ubukana, ikintu gifata amazi, ikintu gikomeza guhagarara, ikintu gikwirakwiza, ikintu gitanga filime.
Kubika amazi muri eteri ya selulosi
Mu gukora ibikoresho by'ubwubatsi, cyane cyane imvange yumye, eteri ya selulose igira uruhare rudasimburwa, cyane cyane mu gukora imvange yihariye (imvange yahinduwe), ni igice cy'ingenzi.
Uruhare rw'ingenzi rwa eteri ya cellulose ishonga mu mazi muri mortilari rufite ahanini ibintu bitatu, kimwe ni ubushobozi bwiza bwo kubika amazi, icya kabiri ni ingaruka z'uburyo mortilari ikora neza kandi ikaba thixotropy, naho icya gatatu ni uburyo ikorana na sima.
Kugumana amazi ya eteri ya selulosi, biterwa n'ishingiro rya hydroscopicity, imiterere ya mortil, ubugari bw'urwego rwa mortil, gukenera amazi ya mortil, igihe cyo gukamana kw'ibikoresho bya condensation. Kugumana amazi kwa eteri ya selulosi bituruka ku gushonga no kubura amazi kwa eteri ya selulosi ubwayo. Birazwi ko iminyururu ya molekile ya selulosi, nubwo irimo umubare munini w'amatsinda ya OH afite amazi menshi, idashonga mu mazi kubera imiterere yayo ya crystalline. Ubushobozi bwo gukama kw'amatsinda ya hydroxyl yonyine ntibuhagije kugira ngo bwishyure iminyururu ikomeye ya hydrogen hamwe n'imbaraga za van der Waals. Iyo iminyururu yinjijwe mu munyururu wa molekile, si iminyururu gusa isenya umunyururu wa hydrogen, ahubwo n'iminyururu ya hydrogen ihuza iminyururu iracika bitewe no guhuza iminyururu iri hafi aho. Uko iminyururu iba minini, ni ko intera iri hagati ya molekile iba nini. Uko ingaruka za hydrogen bond effect zigenda zisenyuka cyane, cellulose lattice yagutse, igisubizo kijya muri eteri ya selulosi kiba gishonga mu mazi, bigatuma habaho umuti wa viscosity nyinshi. Uko ubushyuhe bugenda bwiyongera, amazi ya polymer aragabanuka kandi amazi ari hagati y’iminyururu arasohoka. Iyo ingaruka yo kubura amazi ihagije, molekile zitangira kwishyira hamwe maze gel ikazingira mu buryo butatu. Ibintu bigira ingaruka ku kubika amazi muri mortier birimo ubushyuhe bwa cellulose ether, ingano, ubunini bw’uduce duto n’ubushyuhe bwa serivisi.
Uko eteri ya selulosi irushaho kuba nini, ni ko imikorere myiza yo kubika amazi, ni nako imiterere y’umuti wa polymer irushaho kuba myiza. Uburemere bwa molekile (urwego rwa polymerization) bwa polymer nabwo bugenwa n’uburebure n’imiterere y’imiterere ya molekile y’urunigi, kandi ikwirakwizwa ry’umubare w’ibintu bisimbura bigira ingaruka zitaziguye ku rugero rw’imitsi. [eta] = Km alpha
Uburemere bw'ibisubizo bya polymeri mu buryo bufatika
Uburemere bwa molekile ya M polima
α polymer ihoraho
Igipimo cy'umuti wa K viscosity
Uburemere bw'umuti wa polymer buterwa n'uburemere bwa molekile ya polymer. Uburemere n'ubwinshi bw'umuti wa eteri ya selulose bifitanye isano n'ikoreshwa ritandukanye. Kubwibyo, buri eteri ya selulose ifite uburyo butandukanye bwo kugabanya uburemere, uburyo bwo kugenzura uburemere bushingiye ahanini ku kwangirika kwa selulose ya alkali, ni ukuvuga kuvunika k'umuyoboro wa molekile ya selulose kugira ngo bigerweho.
Ku bunini bw'uduce, uko agace gato kaba gato, ni ko amazi arushaho kugumana neza. Uduce tunini twa eteri ya selulose duhura n'amazi, ubuso buhita bushonga bugakora jeli yo gupfunyika ibikoresho kugira ngo hirindwe ko molekile z'amazi zikomeza kwinjira, rimwe na rimwe kuvanga igihe kirekire ntibishobora gushonga kimwe, hakavuka umuti w'ibirundo cyangwa agglomerate. Gushonga kwa eteri ya selulose ni kimwe mu bintu bituma umuntu ahitamo eteri ya selulose.
Ububyimbirwe na thixotropi ya eteri ya selulose
Ingaruka ya kabiri ya eteri ya selulosi - ubunini bushingiye kuri: urwego rwa polymerization ya eteri ya selulosi, ubwinshi bw'umuti, igipimo cyo gukata, ubushyuhe n'ibindi. Imiterere ya gelation y'umuti ni umwihariko wa alkyl cellulose n'ibikomoka kuri yo byahinduwe. Imiterere ya gelation ifitanye isano n'urwego rwo gusimbuza, ubwinshi bw'umuti n'inyongera. Ku bikomoka kuri hydroxyl alkyl byahinduwe, imiterere ya gel nayo ifitanye isano n'urwego rwo guhindura hydroxyl alkyl. Ku gipimo cy'umuti cya viscosity nke ya MC na HPmc hashobora gutegurwa 10%-15% y'umuti, viscosity iri hagati ya MC na HPmc hashobora gutegurwa 5%-10% y'umuti naho viscosity iri hejuru ya MC na HPmc hashobora gutegurwa 2%-3% y'umuti, kandi ubusanzwe viscosity ya eteri ya selulosi nayo ihabwa amanota ya 1%-2%. Ubushobozi bwo gukurura eteri ya cellulose ifite uburemere bwinshi, igipimo kimwe cy'umuti, polymer zitandukanye zifite uburemere butandukanye bwa vis, ubukana n'uburemere bwa molecule bishobora kugaragazwa ku buryo bukurikira, [η] = 2.92 × 10-2 (DPn) 0.905, DPn ni igipimo mpuzandengo cya polymerization cyo hejuru. Eteri ya cellulose ifite uburemere buke bwa molecule kugira ngo yongereho byinshi kugira ngo igere ku bukana bw'intego. Ubukana bwayo ntibushingira cyane ku gipimo cyo gukata, ubukana bwinshi kugira ngo igere ku bukana bw'intego, ingano ikenewe kugira ngo yongerwemo nke, ubukana bushingiye ku bunoze bwo gukurura. Kubwibyo, kugira ngo igere ku bunararibonye runaka, ingano runaka ya eteri ya cellulose (ubwinshi bw'umuti) n'ubukana bw'umuti bigomba kwemezwa. Ubushyuhe bwa gelation bw'umuti bwagabanutse ku buryo bugororotse hamwe n'ubwiyongere bw'igipimo cy'umuti, kandi gelation yabaye ku bushyuhe bw'icyumba nyuma yo kugera ku gipimo runaka. HPmc ifite igipimo kinini cya gelation ku bushyuhe bw'icyumba.
Uburyo ibintu bimeze bushobora kandi guhindurwa hakoreshejwe guhitamo ingano y'uduce duto n'uturemangingo twa cellulose hamwe n'ibipimo bitandukanye byo guhinduka. Icyo bita guhindura ni ukwinjizwa kw'itsinda rya hydroxyl alkyl mu rugero runaka rwo gusimbuza imiterere y'amagufwa ya MC. Mu guhindura agaciro k'isimbuza ry'ibintu bibiri, ni ukuvuga agaciro k'isimbuza ry'ibintu bya DS na MS by'amatsinda ya methoxy na hydroxyl. Imiterere itandukanye ya ether ya cellulose irakenewe mu guhindura agaciro k'isimbuza ry'ubwoko bubiri bw'ibintu.
isano iri hagati y’ubudahinduka n’impinduka. Ku ishusho ya 5, kongeramo eteri ya selulose bigira ingaruka ku mikoreshereze y’amazi ya mortiweri kandi bihindura ikigereranyo cy’amazi na sima, ari na byo bituma amazi arushaho kuzura. Uko ingano ingana ni ko amazi akoreshwa cyane.
Eteri za selulosi zikoreshwa mu bikoresho by’ubwubatsi birimo ifu zigomba gushonga vuba mu mazi akonje kandi zigatanga uburyo bukwiye bwo gukora neza. Iyo igipimo runaka cyo gukata kikiri cyuzuye kandi gikonje, ni ibicuruzwa bidafite ubuziranenge cyangwa bifite ireme rihagije.
Hariho kandi isano nziza hagati y’uburyo ibintu bimeze nk’ibice bya sima n’ingano ya eteri ya selulose, eteri ya selulose ishobora kongera cyane ubukana bwa sima, uko ingano yayo iba nini, niko ingaruka zayo zigaragara cyane.
Umuti w’amazi wa Cellulose ether ufite ubushyuhe bwinshi ufite thixotropy nyinshi, ikaba ari imwe mu miterere ya ether ya cellulose. Ubusanzwe, imiterere y’amazi ya polymer zo mu bwoko bwa Mc irangwa n’ubushyuhe bwa pseudoplastic, butari thixotropic munsi y’ubushyuhe bwa gel, ariko imiterere y’amazi ya Newtonian ku gipimo gito cyo gukata. Ubushyuhe bwa Pseudoplasticity buriyongera uko uburemere bwa molekile cyangwa ubunini bwa ether ya cellulose bwiyongera kandi ntibushingiye ku bwoko n’ingano byayo. Kubwibyo, ether za cellulose zo mu rwego rumwe rwa viscosity, zaba MC, HPmc cyangwa HEmc, zihora zigaragaza imiterere imwe ya rheological igihe cyose ubushyuhe n’ubushyuhe biguma bihoraho. Iyo ubushyuhe bwiyongeye, gel y’imiterere iraremwa maze habaho urujya n’uruza rwa thixotropic rwinshi. Ether za cellulose zifite ubushyuhe bwinshi n’ubushyuhe buke zigaragaza thixotropy ndetse no munsi y’ubushyuhe bwa gel. Iyi miterere ni ingirakamaro cyane mu kubaka morti yo kubaka kugira ngo ihindure uburyo bwayo bwo kugenda n’uburyo bwo kumanika. Aha hagomba gusobanurwa ko uko eteri ya selulosi irushaho kuba nziza, ni ko amazi agumana neza, ariko uko eteri ya selulosi irushaho kuba nyinshi, ni ko uburemere bwa molekile ya selulosi burushaho kuba bwinshi, bityo ubushobozi bwayo bwo gushonga bugabanuka, bigira ingaruka mbi ku bwinshi bw’imvange n’imikorere y’inyubako. Uko eteri ya selulosi irushaho kuba nyinshi, ni ko ingaruka zo gushonga zigaragara cyane, ariko si isano yuzuye. Eteri ya selulosi igabanuka, ariko yahinduwe mu kunoza imbaraga z’inyubako za selulosi itose, igira imikorere myiza cyane, hamwe no kwiyongera kwa eteri ya selulosi irushaho kuba nziza.
Igihe cyo kohereza ubutumwa: Werurwe-30-2022