Cellulose ether ni polymer yubukorikori ikozwe muri selile karemano nkibikoresho fatizo muguhindura imiti. Ether ya selile ni inkomoko ya selulose karemano, umusaruro wa selile ether na polymer synthique iratandukanye, ibikoresho byayo byibanze ni selile, ibinyabuzima bya polymer bisanzwe. Bitewe nuburyo bwihariye bwimiterere ya selile, selile ubwayo ntabwo ifite ubushobozi bwo kubyitwaramo na etherifying agent. Ariko nyuma yo kuvura imiti yabyimbye, isano ikomeye ya hydrogène hagati yiminyururu ya molekile n'iminyururu yarasenyutse, maze ibikorwa byitsinda rya hydroxyl birekurwa muri alkali selulose ifite ubushobozi bwo kubyitwaramo, kandi ether ya selile yabonetse binyuze mubitekerezo bya etherifing agent - OH group - CYANGWA itsinda.
Ibiranga selile ya selile biterwa n'ubwoko, umubare no gukwirakwiza insimburangingo. Itondekanya rya selulose ether nayo ishingiye kubwoko bwinsimburangingo, urwego rwa etherification, solubilité hamwe nibisabwa bifitanye isano. Ukurikije ubwoko bwinsimburangingo kumurongo wa molekile, irashobora kugabanywamo ether imwe hamwe na ether ivanze. Ubusanzwe MC ikoreshwa nka ether imwe, mugihe HPmc ni ether ivanze. Methyl selulose ether MC ni selile isanzwe ya glucose ya hydroxyl ni hydroxyl isimburwa na formulaire yibicuruzwa [CO H7O2 (OH) 3-H (OCH3) H] X, hydroxypropyl methyl selulose ether HPmc nigice kuri hydroxyl ni igice ya methoxide yasimbuwe, ikindi gice cya hydroxypropyl yasimbuye ibicuruzwa, Inzira yimiterere ni [C6H7O2 (OH) 3-MN (OCH3) M [OCH2CH (OH) CH3] N] X na hydroxyethyl methyl selulose ether HEmc, ikoreshwa cyane kandi igurishwa ku isoko.
Kuva mubishobora gukemurwa birashobora kugabanywa muburyo bwa ionic n'ubwoko butari ionic. Amazi ashonga adafite ionic selulose ether agizwe ahanini na alkyl ether na hydroxyl alkyl ether ibyiciro bibiri byubwoko. Ionic Cmc ikoreshwa cyane mubikoresho byogeza, imyenda, gucapa, ibiryo no gukoresha peteroli. Non-ionic MC, HPmc, HEmc nibindi bikoreshwa cyane mubikoresho byubwubatsi, gutwikira latx, ubuvuzi, chimie ya buri munsi nibindi. Nkumubyimba, umukozi wo kubika amazi, stabilisateur, gutatanya, umukozi ukora firime.
Kubika amazi ya selile
Mu gukora ibikoresho byubwubatsi, cyane cyane byumye bivanze, selulose ether igira uruhare rudasubirwaho, cyane cyane mugukora minisiteri idasanzwe (minisiteri yahinduwe), nigice cyingenzi.
Uruhare rwingenzi rwa selireose ya elegitoronike ya ether muri minisiteri ifite ibintu bitatu, kimwe nubushobozi buhebuje bwo gufata amazi, icya kabiri ningaruka ziterwa na minisiteri na thixotropy, naho icya gatatu ni imikoranire na sima.
Kugumana amazi ya selile ya selile, biterwa nishingiro rya hydroscopicity, ibigize minisiteri, uburebure bwa minisiteri, amazi ya minisiteri, igihe cyo guteranya ibintu. Kugumana amazi ya selile ether ituruka kumashanyarazi no kubura umwuma wa selile ubwayo. Birazwi neza ko iminyururu ya selile ya selile, nubwo irimo umubare munini wamatsinda ya OH afite amazi menshi, ntashobora gushonga mumazi kubera imiterere yabyo. Ubushobozi bwa hydration bwamatsinda ya hydroxyl yonyine ntibihagije kugirango wishyure ingufu za hydrogène intermolecular ningufu za van der Waals. Iyo insimburangingo zinjijwe mumurongo wa molekile, ntabwo insimburangingo zangiza urunigi rwa hydrogène gusa, ariko kandi imigozi ya hydrogène ihuza imiyoboro iracika kubera guhuza insimburangingo hagati yiminyururu yegeranye. Ninini insimburangingo nini, nini intera iri hagati ya molekile. Kurimbuka kwinshi kwingaruka za hydrogène, kwaguka kwa selile ya selile, igisubizo muri selile ya selile ihinduka amazi, gushiramo igisubizo cyinshi. Mugihe ubushyuhe buzamutse, hydrated ya polymer iragabanuka kandi amazi ari hagati yiminyururu yirukanwa. Iyo ingaruka yo kubura umwuma ihagije, molekile zitangira kwegeranya hanyuma gel ikazunguruka mumurongo wibice bitatu. Mu bintu bigira ingaruka ku gufata amazi ya minisiteri harimo selile ya ether viscosity, dosiye, ubwiza bwa selile hamwe nubushyuhe bwa serivisi.
Ninshi ubwiza bwa selulose ether, nuburyo bwiza bwo gufata amazi, ubwiza bwumuti wa polymer. Uburemere bwa molekuline (urwego rwa polymerisation) ya polymer nabwo bugenwa nuburebure na morphologie yimiterere ya molekile yiminyururu, kandi ikwirakwizwa ryumubare wabasimbuye bigira ingaruka muburyo butagaragara. [eta] = Km alpha
Imbere ya viscosity ya polymer ibisubizo
M polymer uburemere
α polymer iranga guhoraho
K coefficient de coiffe
Ubwiza bwumuti wa polymer biterwa nuburemere bwa molekuline ya polymer. Ubukonje hamwe nubushakashatsi bwa selulose ether ibisubizo bifitanye isano nibikorwa bitandukanye. Kubwibyo, buri selile ether ifite ibintu byinshi bitandukanye byerekana ububobere, kugenzura ibishishwa nabyo biterwa ahanini no kwangirika kwa alkali selile, aribyo kuvunika urunigi rwa selile kugirango bigerweho.
Kubunini buke, nibyiza cyane, niko gufata amazi neza. Ibice binini bya selulose ether ihura namazi, hejuru ihita ishonga hanyuma igakora gel kugirango ipfundike ibikoresho kugirango irinde molekile zamazi gukomeza kwinjira, rimwe na rimwe umwanya muremure ntushobora gukwirakwira neza gushonga, gushiraho igisubizo cyibyondo cyangwa ibyondo cyangwa aglomerate. Ubushobozi bwa selile ether ni kimwe mubintu byo guhitamo selile.
Kubyimba hamwe na thixotropy ya selile ether
Ingaruka ya kabiri ya selulose ether - kubyibuha biterwa na: selulose ether polymerisiyasi, ibisubizo byibisubizo, igipimo cyogosha, ubushyuhe nibindi bihe. Imiterere ya gelation yumuti yihariye kuri alkyl selulose nibiyikomokaho. Ibiranga gelation bifitanye isano nurwego rwo gusimbuza, kwibanda kubisubizo hamwe ninyongera. Kuri hydroxyl alkyl ikomokaho, imiterere ya gel nayo ijyanye nurwego rwa hydroxyl alkyl ihinduka. Kubisubizo byibisubizo bya viscosity nkeya MC na HPmc birashobora gutegurwa 10% -15% yumuti wibisubizo, viscosity MC na HPmc birashobora gutegurwa 5% -10% igisubizo hamwe nubwiza bwinshi MC na HPmc birashobora gutegurwa gusa 2% -3% igisubizo, kandi mubisanzwe viscosity ya selulose ether nayo ishyirwa mubikorwa na 1% -2% igisubizo. Uburemere bukabije bwa selile selile ether kubyimbye neza, guhuriza hamwe igisubizo, polimeri yuburemere butandukanye ifite ububobere butandukanye, ubukonje nuburemere bwa molekuline bishobora kugaragazwa gutya, [η] = 2.92 × 10-2 (DPn) 0.905, DPn ni impuzandengo urwego rwa polymerisation rwo hejuru. Uburemere buke bwa selile selile ether kugirango wongere byinshi kugirango ugere ku ntego yo kwiyegereza. Ubukonje bwarwo ntibushingiye cyane ku gipimo cyogosha, ubwiza bwinshi kugirango ugere ku ntego yo kwiyegeranya, amafaranga akenewe kugirango yongereho make, ibishishwa biterwa no kubyimba neza. Kubwibyo, kugirango ugere kumurongo umwe, umubare runaka wa selulose ether (concentration yumuti) hamwe nubwiza bwibisubizo bigomba kwemezwa. Ubushyuhe bwa gelation yumuti bwagabanutse cyane hamwe no kwiyongera kwumuti wibisubizo, kandi gelation yabaye mubushyuhe bwicyumba nyuma yo kugera kumurongo runaka. HPmc ifite ubushyuhe bwinshi mubushyuhe bwicyumba.
Ihame rishobora kandi guhindurwa muguhitamo ingano ya selile na selile ya selile hamwe nimpamyabumenyi zitandukanye zo guhindura. Ibyo bita guhindura ni ugutangiza hydroxyl alkyl groupe murwego runaka rwo gusimbuza imiterere ya skeleton ya MC. Muguhindura igereranyo cyo gusimbuza indangagaciro zibiri zasimbuwe, ni ukuvuga, DS na MS ugereranije nindangagaciro zo gusimbuza imikorere ya hydroxyl. Ibintu bitandukanye bya selulose ether birasabwa muguhindura agaciro kagereranya indangagaciro zubwoko bubiri bwinsimburangingo.
isano iri hagati yo guhinduka no guhindura. Mu gishushanyo cya 5, kongeramo ether ya selile bigira ingaruka kumikoreshereze yamazi ya minisiteri kandi bigahindura igipimo cyamazi gihuza amazi na sima, ningaruka yo kwiyongera. Iyo dosiye iri hejuru, niko gukoresha amazi menshi.
Ether ya selile ikoreshwa mubikoresho byubaka ifu igomba gushonga vuba mumazi akonje kandi igatanga sisitemu ihamye. Niba igipimo cyogosha cyatanzwe kiracyari flocculent na colloidal nigicuruzwa kitujuje ubuziranenge cyangwa cyiza.
Hariho kandi umurongo mwiza mwiza hagati ya sima slurry idahwitse hamwe na dosiye ya selulose ether, selulose ether irashobora kongera cyane ububobere bwa minisiteri, uko dosiye nini, niko bigaragara ingaruka.
Cellulose ether amazi yo mumazi hamwe nubukonje bwinshi afite thixotropy nyinshi, nikimwe mubiranga selile ya ether. Ibisubizo byamazi ya polimeri yo mu bwoko bwa Mc mubisanzwe bifite pseudoplastique, non-thixotropic fluidity munsi yubushyuhe bwa gel, ariko ibintu bya Newtonian bitemba ku gipimo gito. Pseudoplastique yiyongera hamwe no kwiyongera kwuburemere bwa molekuline cyangwa kwibumbira hamwe kwa selile ether kandi ntigengwa nubwoko bwinsimburangingo. Kubwibyo, selile ya ether yo murwego rumwe rwijimye, yaba MC, HPmc cyangwa HEmc, burigihe yerekana imiterere imwe ya rheologiya mugihe cyose ubushyuhe nubushyuhe bikomeza guhoraho. Iyo ubushyuhe bwiyongereye, gel yubatswe ikorwa kandi tixotropique itemba ibaho. Ethers ya selile ifite ubukana bwinshi hamwe nubukonje buke bwerekana thixotropy ndetse no munsi yubushyuhe bwa gel. Uyu mutungo ufite inyungu nyinshi mukubaka inyubako ya minisiteri kugirango uhindure imigendekere yimitungo yimanitse. Birakenewe gusobanurwa hano ko uko ubukonje bwa ether ya selireose, niko gufata amazi neza, ariko uko ubukonje bugenda bwiyongera, niko uburemere bwa molekuline bugereranije na selile ya selile, kugabanuka gukwiranye kwayo, bigira ingaruka mbi kuri kwibanda kuri minisiteri no gukora imirimo yo kubaka. Iyo hejuru yubusembwa, niko bigaragara cyane kubyimbye bya minisiteri, ariko ntabwo ari isano yuzuye. Ubukonje buke, ariko bwahinduwe na selulose ether mugutezimbere imbaraga zimiterere ya minisiteri itose ifite imikorere myiza cyane, hamwe no kwiyongera kwijimye, selile ya ether yabitswe neza.
Igihe cyo kohereza: Werurwe-30-2022