1. ʻO ke ʻano hana a me ka hoʻomākaukau ʻana o ka cellulose ether
Hōʻike ka Kiʻi 1 i ke ʻano maʻamau o nā ethers cellulose. Hoʻololi kēlā me kēia ʻāpana bD-anhydroglucose (ka ʻāpana hana hou o ka cellulose) i hoʻokahi hui ma nā kūlana C (2), C (3) a me C (6), ʻo ia hoʻi, hiki ke loaʻa a hiki i ʻekolu mau hui ether. Ma muli o nā pilina hydrogen intra-chain a me inter-chain onā macromolecules cellulose, he paʻakikī ke hoʻoheheʻe ʻia i ka wai a me ka aneane nā mea hoʻoheheʻe organik āpau. ʻO ka hoʻolauna ʻana o nā hui ether ma o ka etherification e hoʻopau i nā pilina hydrogen intramolecular a me intermolecular, hoʻomaikaʻi i kona hydrophilicity, a hoʻomaikaʻi nui i kona solubility i nā media wai.
ʻO nā mea pani etherified maʻamau he mau hui alkoxy kaumaha molekala haʻahaʻa (1 a 4 mau ʻātoma kalapona) a i ʻole nā hui hydroxyalkyl, a laila hiki ke pani ʻia e nā hui hana ʻē aʻe e like me ka carboxyl, hydroxyl a i ʻole nā hui amino. Hiki i nā mea pani ke ʻano o hoʻokahi, ʻelua a ʻoi aku paha. Ma ke kaulahao macromolecular cellulose, ua pani ʻia nā hui hydroxyl ma nā kūlana C (2), C (3) a me C (6) o kēlā me kēia ʻāpana glucose i nā ʻāpana like ʻole. Ma ke ʻano koʻikoʻi, ʻaʻohe ʻano kemika paʻa o ka cellulose ether, koe wale nō kēlā mau huahana i pani piha ʻia e hoʻokahi ʻano hui (ua pani ʻia nā hui hydroxyl ʻekolu). Hiki ke hoʻohana wale ʻia kēia mau huahana no ka nānā ʻana i ka hale hana a me ka noiʻi, a ʻaʻohe waiwai kalepa.
(a) Ke ʻano laulā o ʻelua mau ʻāpana anhydroglucose o ke kaulahao molekala cellulose ether, R1~R6=H, a i ʻole kahi pani organik;
(b) He ʻāpana kaulahao molekala o ka carboxymethylhydroxyethyl cellulose, ʻo ke kekelē o ka pani ʻana o ka carboxymethyl he 0.5, ʻo ke kekelē o ka pani ʻana o ka hydroxyethyl he 2.0, a ʻo ke kekelē o ka pani ʻana o ka molar he 3.0. Hōʻike kēia ʻano i ka pae pani awelika o nā hui etherified, akā he mea maʻamau ʻole nā mea pani.
No kēlā me kēia pani, ua hōʻike ʻia ka nui o ka etherification e ke kekelē o ka waiwai pani DS. ʻO ka laulā o DS he 0 ~ 3, ʻo ia ka mea like me ka helu awelika o nā hui hydroxyl i pani ʻia e nā hui etherification ma kēlā me kēia ʻāpana anhydroglucose.
No nā hydroxyalkyl cellulose ethers, e hoʻomaka ka hopena hoʻololi i ka etherification mai nā hui hydroxyl manuahi hou, a hiki ke helu ʻia ke kekelē o ka hoʻololi ʻana e ka waiwai MS, ʻo ia hoʻi, ke kekelē molar o ka hoʻololi ʻana. Hōʻike ia i ka helu awelika o nā moles o ka mea hana etherifying i hoʻohui ʻia i kēlā me kēia ʻāpana anhydroglucose. ʻO kahi mea hana maʻamau ʻo ethylene oxide a loaʻa i ka huahana kahi substituent hydroxyethyl. Ma ke Kiʻi 1, ʻo ka waiwai MS o ka huahana he 3.0.
Ma ke kumumanaʻo, ʻaʻohe palena kiʻekiʻe no ka waiwai MS. Inā ʻike ʻia ka waiwai DS o ke kekelē o ka pani ʻana ma kēlā me kēia hui apo glucose, ʻo ka lōʻihi kaulahao awelika o ke kaulahao ʻaoʻao ether. Hoʻohana pinepine kekahi mau mea hana i ka hapa nui (wt%) o nā hui etherification like ʻole (e like me -OCH3 a i ʻole -OC2H4OH) e hōʻike i ka pae pani a me ke kekelē ma kahi o nā waiwai DS a me MS. Hiki ke hoʻololi ʻia ka hapa nui o kēlā me kēia hui a me kāna waiwai DS a i ʻole MS ma ka helu maʻalahi.
ʻO ka hapa nui o nā cellulose ethers he mau polymers wai-soluble, a ʻo kekahi he hapa hoʻoheheʻe ʻia i loko o nā mea hoʻoheheʻe organik. Loaʻa i ka Cellulose ether nā ʻano o ka pono kiʻekiʻe, ke kumukūʻai haʻahaʻa, ka hana maʻalahi, ka haʻahaʻa haʻahaʻa a me nā ʻano like ʻole, a ke hoʻonui nei ke koi a me nā kahua noi. Ma ke ʻano he mea kōkua, loaʻa i ka cellulose ether ka hiki ke hoʻohana nui ʻia ma nā ʻano ʻoihana like ʻole. hiki ke loaʻa ma o MS/DS.
Ua hoʻokaʻawale ʻia nā ethers cellulose e like me ke ʻano kemika o nā mea pani i nā ethers anionic, cationic a me nonionic. Hiki ke hoʻokaʻawale ʻia nā ethers nonionic i nā huahana wai-hoʻoheheʻe ʻia a me nā huahana ʻaila-hoʻoheheʻe ʻia.
Ua helu ʻia nā huahana i hoʻomohala ʻia ma ka ʻaoʻao luna o ka Papa 1. ʻO ka ʻaoʻao haʻahaʻa o ka Papa 1 e helu ana i kekahi mau hui etherification i ʻike ʻia, ʻaʻole i lilo i mau huahana kālepa koʻikoʻi.
Hiki ke kapa ʻia ke kauoha pōkole o nā pani ether i hui ʻia e like me ke kauoha pīʻāpā a i ʻole ka pae o ka DS (MS), no ka laʻana, no 2-hydroxyethyl methylcellulose, ʻo ka pōkole ʻo HEMC, a hiki ke kākau ʻia ʻo MHEC e hōʻike i ka pani methyl.
ʻAʻole hiki ke komo maʻalahi nā hui hydroxyl ma ka cellulose e nā mea etherification, a hana pinepine ʻia ke kaʻina hana etherification ma lalo o nā kūlana alkaline, me ka hoʻohana ʻana i kahi ʻano o ka wai NaOH. Hoʻokumu mua ʻia ka cellulose i loko o ka cellulose alkali pehu me ka wai NaOH, a laila hana i ka hopena etherification me ka mea etherification. I ka wā o ka hana ʻana a me ka hoʻomākaukau ʻana o nā ethers i hui ʻia, pono e hoʻohana ʻia nā ʻano mea etherification like ʻole i ka manawa like, a i ʻole e hana ʻia ka etherification i kēlā me kēia ʻanuʻu ma ka hānai intermittent (inā pono). ʻEhā mau ʻano hopena i ka etherification o ka cellulose, i hōʻuluʻulu ʻia e ke ʻano hana (ua pani ʻia ka cellulosic e Cell-OH) penei:
Hōʻike ka Equation (1) i ka hopena etherification Williamson. ʻO RX kahi ester waikawa inorganic, a ʻo X ka halogen Br, Cl a i ʻole sulfuric acid ester. Hoʻohana nui ʻia ʻo Chloride R-Cl i ka ʻoihana, no ka laʻana, methyl chloride, ethyl chloride a i ʻole chloroacetic acid. Hoʻopau ʻia kahi nui stoichiometric o ke kumu i ia mau hopena. ʻO nā huahana cellulose ether ʻoihana ʻo methyl cellulose, ethyl cellulose a me carboxymethyl cellulose nā huahana o ka hopena etherification Williamson.
ʻO ke ʻano hana (2) ka hana hoʻohui o nā epoxides i hoʻopili ʻia e ke kumu (e like me R=H, CH3, a i ʻole C2H5) a me nā hui hydroxyl ma nā molekole cellulose me ka ʻole o ka hoʻopau ʻana i ke kumu. E hoʻomau paha kēia hana i ka wā e hana ʻia ai nā hui hydroxyl hou i ka wā o ka hana, e alakaʻi ana i ka hoʻokumu ʻana o nā kaulahao ʻaoʻao oligoalkylethylene oxide: ʻO kahi hana like me 1-aziridine (aziridine) e hana i ka aminoethyl ether: Cell-O-CH2-CH2-NH2. ʻO nā huahana e like me ka hydroxyethyl cellulose, hydroxypropyl cellulose a me ka hydroxybutyl cellulose he mau huahana āpau o ka epoxidation i hoʻopili ʻia e ke kumu.
ʻO ke ʻano hana (3) ka hana ma waena o Cell-OH a me nā hui organik e loaʻa ana nā pilina pālua hana i loko o ka alkaline medium, ʻo Y kahi hui electron-withdrawing, e like me CN, CONH2, a i ʻole SO3-Na+. I kēia lā, ʻaʻole i hoʻohana pinepine ʻia kēia ʻano hana ma ka ʻoihana.
ʻAʻole i hoʻomohala ʻia ke ʻano hana (4), ʻo ka etherification me ka diazoalkane.
- Nā ʻano o nā ethers cellulose
Hiki i ka cellulose ether ke monoether a i ʻole ka ether hui ʻia, a ʻokoʻa kona mau waiwai. Aia nā hui hydrophilic haʻahaʻa-pane ma ka macromolecule cellulose, e like me nā hui hydroxyethyl, hiki ke hāʻawi i ka huahana me kahi kekelē o ka solubility wai, ʻoiai no nā hui hydrophobic, e like me ka methyl, ethyl, etc., ʻo ke kekelē kiʻekiʻe wale nō ke hāʻawi i ka huahana i kahi solubility wai, a ʻo ka huahana haʻahaʻa-pane e pehu wale i ka wai a hiki ke hoʻoheheʻe ʻia i loko o ka hopena alkali dilute. Me ka noiʻi hohonu i nā waiwai o nā cellulose ethers, e hoʻomohala mau ʻia a hana ʻia nā cellulose ethers hou a me kā lākou mau kahua noi, a ʻo ka ikaika nui loa ka mākeke noi ākea a hoʻomaʻemaʻe mau ʻia.
ʻO ke kānāwai laulā o ka mana o nā hui i loko o nā ethers i hui pū ʻia ma nā waiwai solubility penei:
1) E hoʻonui i ka ʻike o nā hui hydrophobic i loko o ka huahana e hoʻonui i ka hydrophobicity o ether a hoʻohaʻahaʻa i ke kiko gel;
2) Hoʻonui i ka ʻike o nā hui hydrophilic (e like me nā hui hydroxyethyl) e hoʻonui i kona kiko gel;
3) He kūikawā ka hui hydroxypropyl, a hiki i ka hydroxypropylation kūpono ke hoʻohaʻahaʻa i ka mahana gel o ka huahana, a e piʻi hou ka mahana gel o ka huahana hydroxypropylated waena, akā ʻo ka pae kiʻekiʻe o ka hoʻololi ʻana e hōʻemi i kona kiko gel; ʻO ke kumu ma muli o ke ʻano lōʻihi o ke kaulahao kalapona kūikawā o ka hui hydroxypropyl, ka hydroxypropylation haʻahaʻa, nā pilina hydrogen nāwaliwali i loko a ma waena o nā molekala i loko o ka cellulose macromolecule, a me nā hui hydroxyl hydrophilic ma nā kaulahao lālā. He mana ka wai. Ma ka ʻaoʻao ʻē aʻe, inā kiʻekiʻe ka hoʻololi ʻana, e loaʻa ka polymerization ma ka hui ʻaoʻao, e emi ana ka ʻike pili o ka hui hydroxyl, e piʻi ka hydrophobicity, a e emi ana ka solubility.
Ka hana ʻana a me ka noiʻi ʻana oʻEtera celluloseHe moʻolelo lōʻihi ko Suida. I ka makahiki 1905, ua hōʻike mua ʻo Suida i ka etherification o ka cellulose, kahi i methylated me dimethyl sulfate. Ua hoʻopaʻa ʻia nā nonionic alkyl ethers e Lilienfeld (1912), Dreyfus (1914) a me Leuchs (1920) no nā cellulose ethers wai-soluble a i ʻole ka ʻaila-soluble. Ua hana ʻo Buchler lāua ʻo Gomberg i ka benzyl cellulose i ka makahiki 1921, ua hana mua ʻia ka carboxymethyl cellulose e Jansen i ka makahiki 1918, a ua hana ʻo Hubert i ka hydroxyethyl cellulose i ka makahiki 1920. I ka hoʻomaka ʻana o nā makahiki 1920, ua kūʻai ʻia ka carboxymethylcellulose ma Kelemania. Mai ka makahiki 1937 a i ka makahiki 1938, ua hoʻokō ʻia ka hana ʻoihana o MC a me HEC ma ʻAmelika Hui Pū ʻIa. Ua hoʻomaka ʻo Suedena i ka hana ʻana o ka EHEC wai-soluble i ka makahiki 1945. Ma hope o 1945, ua hoʻonui koke ʻia ka hana ʻana o ka cellulose ether ma ʻEulopa Komohana, ʻAmelika Hui Pū ʻIa a me Iapana. I ka hopena o 1957, ua hoʻokomo mua ʻia ʻo Kina CMC i ka hana ma ka Hale Hana Celluloid o Shanghai. I ka makahiki 2004, ʻo ka hiki ke hana o koʻu ʻāina he 30,000 tone o ka ionic ether a me 10,000 tone o ka non-ionic ether. I ka makahiki 2007, e hōʻea ia i 100,000 tone o ka ionic ether a me 40,000 tone o ka Nonionic ether. Ke puka mau nei nā ʻoihana ʻenehana hui ma ka home a me nā ʻāina ʻē, a ke hoʻomaikaʻi mau nei ka hiki ke hana cellulose ether a me ka pae loea o Kina.
I nā makahiki i hala iho nei, ua hoʻomohala mau ʻia nā monoethers cellulose he nui a me nā ethers i hui pū ʻia me nā waiwai DS like ʻole, nā viscosities, ka maʻemaʻe a me nā waiwai rheological. I kēia manawa, ʻo ke kiko o ka hoʻomohala ʻana i ke kahua o nā ethers cellulose ka hoʻohana ʻana i ka ʻenehana hana holomua, ʻenehana hoʻomākaukau hou, nā lako hou, nā huahana hou, nā huahana kiʻekiʻe, a me nā huahana ʻōnaehana e pono e noiʻi ʻenehana.
Ka manawa hoʻouna: ʻApelila-28-2024