1.Imiterere no gutegura ihame rya selile ether
Igishushanyo 1 kirerekana imiterere isanzwe ya selile. Buri gice cya bD-anhydroglucose (igice gisubiramo selile) gisimbuza itsinda rimwe kumwanya wa C (2), C (3) na C (6), ni ukuvuga ko hashobora kubaho amatsinda agera kuri atatu ya ether. Bitewe n'umunyururu-hagati hamwe na hydrogène ihuza imiyoboro yaselile macromolecules, biragoye gushonga mumazi hafi ya yose yumuti. Kwinjiza amatsinda ya ether binyuze muri etherification yangiza imigozi ya hydrogène yo mu bwoko bwa intermolecular na intermolecular, itezimbere hydrophilicity, kandi inoze cyane gukemura kwayo mubitangazamakuru byamazi.
Ubusanzwe insimburangingo ya etherifike ni matsinda mato ya alkoxy yuburemere (atome ya karubone 1 kugeza kuri 4) cyangwa hydroxyalkyl, ishobora noneho gusimburwa nandi matsinda akora nka carboxyl, hydroxyl cyangwa amatsinda ya amino. Ibisimburwa birashobora kuba bimwe, bibiri cyangwa byinshi bitandukanye. Kuruhande rwa selile ya macromolecular, amatsinda ya hydroxyl kumyanya C (2), C (3) na C (6) ya buri gice cya glucose asimburwa muburyo butandukanye. Mu magambo make, selile ether muri rusange ntabwo ifite imiterere yimiti ihamye, usibye ibyo bicuruzwa byasimbuwe rwose nubwoko bumwe bwitsinda (amatsinda atatu ya hydroxyl asimburwa). Ibicuruzwa birashobora gukoreshwa gusa mubisesengura na laboratoire, kandi nta gaciro byubucuruzi bifite.
(a) Imiterere rusange yibice bibiri bya anhydroglucose yingirabuzimafatizo ya selile ya selile, R1 ~ R6 = H, cyangwa insimburangingo;
(b) Urunigi rwa molekile igice cya carboxymethylhydroxyethyl selile, urwego rwo gusimbuza carboxymethyl ni 0.5, urwego rwo gusimbuza hydroxyethyl ni 2.0, naho urwego rwo gusimbuza molari ni 3.0. Iyi miterere yerekana impuzandengo yo gusimbuza urwego rwamatsinda, ariko abasimbuye mubyukuri.
Kuri buri cyasimbuwe, umubare rusange wa etherification ugaragazwa nurwego rwo gusimbuza DS agaciro. Urwego rwa DS ni 0 ~ 3, bihwanye numubare mpuzandengo wamatsinda ya hydroxyl yasimbuwe nitsinda rya etherification kuri buri gice cya anhydroglucose.
Kuri hydroxyalkyl selulose ethers, reaction yo gusimbuza izatangira etherification mumatsinda mashya ya hydroxyl yubusa, kandi urwego rwo gusimburwa rushobora kugereranywa nagaciro ka MS, ni ukuvuga urwego rwo gusimbuza. Yerekana impuzandengo ya mole ya etherifying agent reaction yongewe kuri buri gice cya anhydroglucose. Ubusanzwe reaction ni Ethylene oxyde kandi ibicuruzwa bifite hydroxyethyl. Igishushanyo cya 1, MS agaciro k'ibicuruzwa ni 3.0.
Mubyukuri, nta karimbi kari hejuru yagaciro ka MS. Niba agaciro ka DS kurwego rwo gusimbuza buri tsinda ryimpeta ya glucose rizwi, uburebure buringaniye bwurunigi rwurunigi rwa ether Bamwe mubakora uruganda nabo bakunze gukoresha igice kinini (wt%) cyamatsinda atandukanye ya etherification (nka -OCH3 cyangwa -OC2H4OH) kugirango bagaragaze urwego rusimburwa nurwego aho kuba DS na MS. Igice kinini cya buri tsinda hamwe nagaciro ka DS cyangwa MS birashobora guhindurwa kubara byoroshye.
Ethers nyinshi ya selile ni polymer zishonga amazi, kandi zimwe nazo zishonga igice mumashanyarazi. Cellulose ether ifite ibiranga imikorere ihanitse, igiciro gito, gutunganya byoroshye, uburozi buke nubwoko butandukanye, kandi ibisabwa nibisabwa biracyaguka. Nkumufasha wungirije, selile ether ifite ubushobozi bukomeye bwo gukoresha mubice bitandukanye byinganda. urashobora kuboneka na MS / DS.
Ether ya selile yashyizwe mubice ukurikije imiterere yimiti yabasimbuye muri anionic, cationic na nonionic ethers. Ether nonionic irashobora kugabanywamo ibicuruzwa biva mu mazi hamwe n’ibikomoka ku mavuta.
Ibicuruzwa byakozwe mu nganda byashyizwe ku gice cyo hejuru cyimbonerahamwe ya 1. Igice cyo hepfo cyimbonerahamwe ya 1 cyerekana amatsinda azwi ya etherification, atarabaye ibicuruzwa byingenzi byubucuruzi.
Urutonde rwincamake rwibintu bivanze bya ether birashobora kwitwa amazina ukurikije gahunda yinyuguti cyangwa urwego rwa DS (MS) bijyanye, kurugero, kuri 2-hydroxyethyl methylcellulose, amagambo ahinnye ni HEMC, kandi birashobora no kwandikwa nka MHEC kugirango ushire ahabona methyl.
Amatsinda ya hydroxyl kuri selile ntashobora kugerwaho byoroshye na etherification, kandi inzira ya etherifasique ikorwa mugihe cya alkaline, muri rusange ikoresheje kwibanda kumazi wa NaOH. Cellulose yabanje kwibumbira muri alkali selile yabyimbye hamwe na NaOH yumuti wamazi, hanyuma ikagira reaction ya etherification hamwe na agent ya etherification. Mugihe cyo gukora no gutegura ethers ivanze, ubwoko butandukanye bwibikoresho bya etherification bigomba gukoreshwa icyarimwe, cyangwa etherification igomba gukorwa intambwe ku yindi kugaburira rimwe na rimwe (nibiba ngombwa). Hariho ubwoko bune bwibisubizo muri etherification ya selile, byegeranijwe na formulaire ya reaction (selile isimburwa na Cell-OH) kuburyo bukurikira:
Ikigereranyo (1) gisobanura reaction ya Williamson. RX ni acide ya organique, na X ni halogen Br, Cl cyangwa acide sulfurike. Chloride R-Cl isanzwe ikoreshwa mu nganda, urugero, methyl chloride, Ethyl chloride cyangwa aside chloroacetic. Umubare wa stoichiometric wibanze ukoreshwa mubitekerezo nkibi. Inganda za selile zikora inganda methyl selulose, Ethyl selulose na carboxymethyl selulose nibicuruzwa bya Williamson etherification reaction.
Inzira ya reaction (2) niyongeraho reaction ya epoxide yibanze (nka R = H, CH3, cyangwa C2H5) hamwe nitsinda rya hydroxyl kuri molekile ya selile idakoresheje shingiro. Iyi reaction irashobora gukomeza kuko amatsinda mashya ya hydroxyl atangwa mugihe cyo kubyitwaramo, biganisha ku gushiraho iminyururu ya oligoalkylethylene ya oxyde: Igisubizo gisa na 1-aziridine (aziridine) kizakora aminoethyl ether: Cell-O-CH2-CH2-NH2. Ibicuruzwa nka hydroxyethyl selulose, hydroxypropyl selulose na hydroxybutyl selulose byose nibicuruzwa bya epoxidation yibanze.
Inzira yo kwitwara (3) nigisubizo hagati ya Cell-OH hamwe ningingo ngengabuzima zirimo imigozi ibiri ikora muburyo bwa alkaline, Y ni itsinda rikuramo electron, nka CN, CONH2, cyangwa SO3-Na +. Uyu munsi ubu bwoko bwa reaction ntibukoreshwa cyane munganda.
Inzira yo kwitwara (4), etherification hamwe na diazoalkane ntabwo yakozwe munganda.
- Ubwoko bwa selile
Ether ya selile irashobora kuba imwe cyangwa ivanze na ether, kandi imiterere yayo iratandukanye. Hano hari amatsinda ya hydrophilique asimbuwe kuri macromolecule ya selile, nka hydroxyethyl matsinda, ashobora guha ibicuruzwa urugero runaka rwamazi yo gukemura, mugihe kubitsinda rya hydrophobique, nka methyl, Ethyl, nibindi, gusa gusimburana kurwego rwo hejuru birashobora guha ibicuruzwa igisubizo cyamazi cyoroshye, kandi ibicuruzwa bisimbuwe na alkali byabyimbye mumazi cyangwa ibishishwa bisukuye gusa. Hamwe nubushakashatsi bwimbitse kumiterere ya selile ya selile, ether nshya ya selile hamwe nimirima yabyo bizakomeza gutezwa imbere no kubyazwa umusaruro, kandi imbaraga nini zo gutwara ni isoko yagutse kandi ikomeza kunonosorwa.
Amategeko rusange yingaruka zamatsinda muri ethers ivanze kumitungo ikemurwa ni:
1) Kongera ibiri mumatsinda ya hydrophobique mubicuruzwa kugirango wongere hydrophobicity ya ether no kugabanya gel point;
2) Ongera ibiri mumatsinda ya hydrophilique (nka hydroxyethyl matsinda) kugirango wongere ingingo ya gel;
3) Itsinda rya hydroxypropyl ntirisanzwe, kandi hydroxypropylation ikwiye irashobora kugabanya ubushyuhe bwa geli yibicuruzwa, kandi ubushyuhe bwa gel bwibicuruzwa biva mu bwoko bwa hydroxypropylated bizongera kwiyongera, ariko urwego rwo hejuru rwo gusimbuza ruzagabanya aho rwerekeza; Impamvu iterwa nuburebure bwihariye bwa karubone yuburebure bwitsinda rya hydroxypropyl, hydroxypropylation yo mu rwego rwo hasi, intege za hydrogène zacitse intege no hagati ya molekile muri macromolecule ya selile, hamwe nitsinda rya hydrophilique hydroxyl kumurongo wishami. Amazi ariganje. Kurundi ruhande, niba gusimburwa ari hejuru, hazabaho polymerisation kumurwi wuruhande, ugereranije nibiri mumatsinda ya hydroxyl bizagabanuka, hydrophobicity iziyongera, kandi ibisubizo bizagabanuka aho.
Umusaruro n'ubushakashatsi bwaselile etherifite amateka maremare. Mu 1905, Suida yabanje gutanga raporo ya etherifisation ya selile, yashizwemo methyl na sulfate ya dimethyl. Ether ya nonkyic alkyl yatanzwe na Lilienfeld (1912), Dreyfus (1914) na Leuchs (1920) kugirango babone amazi ya elegitoronike cyangwa amavuta ya elegitoronike. Buchler na Gomberg bakoze selile ya benzyl mu 1921, carboxymethyl selulose yakozwe bwa mbere na Jansen mu 1918, Hubert ikora hydroxyethyl selulose mu 1920. Mu ntangiriro ya 1920, carboxymethylcellulose yacururizwaga mu Budage. Kuva mu 1937 kugeza 1938, umusaruro w’inganda za MC na HEC wamenyekanye muri Amerika. Suwede yatangiye gukora EHEC ikora amazi mu 1945. Nyuma ya 1945, umusaruro wa ether wa selile wagutse vuba mu Burayi bw’iburengerazuba, Amerika n'Ubuyapani. Mu mpera za 1957, Ubushinwa CMC bwashyizwe mu bikorwa bwa mbere mu ruganda rwa Celluloid rwa Shanghai. Kugeza 2004, umusaruro wigihugu cyanjye uzaba toni 30.000 za ionic ether na toni 10,000 za ether zitari ionic. Kugeza 2007, izagera kuri toni 100.000 za ionic ether na toni 40.000 za Nonionic ether. Isosiyete ikorana buhanga mu gihugu no hanze yarwo nayo ihora igaragara, kandi Ubushinwa butanga umusaruro wa selile ether nu rwego rwa tekiniki bigenda bitera imbere.
Mu myaka yashize, monoethers ya selile nyinshi hamwe na ethers ivanze ifite indangagaciro zitandukanye za DS, viscosities, isuku nimiterere ya rheologiya byakomeje gutezwa imbere. Kugeza ubu, intego yibanze mu iterambere mu bijyanye na selile ya selile ni ugukoresha ikoranabuhanga rigezweho ry’umusaruro, ikoranabuhanga rishya ryo gutegura, ibikoresho bishya, ibicuruzwa bishya, ibicuruzwa byiza, n’ibicuruzwa bitunganijwe bigomba gukorwaho ubushakashatsi.
Igihe cyo kohereza: Apr-28-2024