Hydroxyethyl methyl cellulose (HEMC) he non-ionic cellulose ether i hoʻohana nui ʻia i ke kūkulu ʻana, nā uhi, nā seramika, nā lāʻau lapaʻau, nā meaʻai a me nā ʻoihana ʻē aʻe. He maikaʻi ko ka HEMC i ka wai, ka mānoanoa, ka paʻa ʻana o ka wai, ka hana kiʻiʻoniʻoni a me ka hoʻopaʻa ʻana i nā waiwai, a he hana koʻikoʻi i ka mortar maloʻo, ka pena latex, ka mea holoi a me nā māla ʻē aʻe.
1. Kaʻina hana
1.1 Hoʻomākaukau mea maka
Hoʻomākaukau nui ʻia ʻo HEMC mai ka cellulose mea kanu maoli, methyl chloride (CH₃Cl), ethylene oxide (C₂H₄O), sodium hydroxide (NaOH) a me nā mea maka.
Cellulose: Hoʻohana pinepine ʻia ka pulp lāʻau a i ʻole ka pulupulu pulupulu ma ke ʻano he kumu kumu nui, kahi e koi ai i ka maʻemaʻe kiʻekiʻe a me ka liʻiliʻi o nā haumia e hōʻoia i ka maikaʻi o ka huahana.
Alkalizer (NaOH): hoʻohana ʻia e hoʻāla i ka cellulose a hoʻomaikaʻi i ka hana ʻana.
ʻAi hoʻoheheʻe (CH₃Cl a me C₂H₄O): hāʻawi i nā pūʻulu methyl a me hydroxyethyl, no laila e hoʻololi ʻia ka cellulose, e hoʻomaikaʻi i ka hoʻoheheʻe wai a me nā waiwai hana.
Mea hoʻoheheʻe organik (e like me isopropanol): hoʻohana ʻia e hoʻopau i nā mea hoʻoheheʻe, e hoʻomalu i ke kaiapuni hopena a hoʻemi i nā ʻaoʻao.
1.2 Lapaʻau Alkalization
Ma hope o ka ʻoki ʻia ʻana o ka cellulose, hoʻohui ʻia ka nui o ka sodium hydroxide solution a lawe ʻia ka mālama alkalization i kahi mahana a me ke kaomi, ʻo ia ka 30-60 mau minuke. ʻO ke kumu nui o ka alkalization ʻo ia ka hoʻonui ʻana i ke kaulahao molekula cellulose a hoʻomaikaʻi i kona reactivity me ka etherifying agent. Hana ʻia kēia kaʻina hana i loko o kahi reactor paʻa me ka hoʻoulu ʻana e hōʻoia i ke komo pono ʻana o ka hopena alkali i loko o ka cellulose.
1.3 Etherification pane
Hoʻopili ka cellulose alkalized me ka methylation a me ka hydroxyethylation reagents (CH₃Cl a me C₂H₄O) i loko o kahi reactor e hana i ka hydroxyethyl methyl cellulose. Loaʻa nā kūlana pane:
Mahana: 60-90°C
Pumi: 0.5-1.5 MPa
Manawa: 2-5 hola
I ka wā o ka hopena, hoʻomau ka hopena o ka methylation a me ka hydroxyethylation i ka manawa like, i hoʻololi ʻia ka ʻāpana hydroxyl (-OH) o ka cellulose e ka methyl (-OCH).₃) a me ka hydroxyethyl (-OCH₂CH₂OH), ma laila e hoʻololi ai i kona solubility a me nā waiwai mānoanoa. I mea e hoʻomaikaʻi ai i ke kiʻekiʻe o ka hoʻololi ʻana (DS a me MS koʻikoʻi), pono e hoʻopaʻa pono i ka hoʻonohonoho a me ka hapa o ka hoʻohui ʻana i ka mea hoʻohui etherification.
1.4 Neutralization a holoi
Ma hope o ka pau ʻana o ka pane ʻana, loaʻa i ka ʻōnaehana ka alkali unreacted, solvent a me nā huahana (e like me NaCl). No laila, pono ka neutralization a me ka holoi ʻana:
Neutralization: E hoʻohana i ka waikawa (e like me ka acetic acid) e hoʻokaʻawale i ka alkali i loko o ka ʻōnaehana a hoʻololi i ka waiwai pH i 6-8.
Holoi: E hoʻohana i ka nui o ka wai wela a i ʻole ka ethanol aqueous solution e holoi pinepine ai i ka cellulose e wehe i nā mea i hana ʻole ʻia a me nā huahana, e hoʻemi i ka maʻi haumia, a hoʻomaikaʻi i ka maʻemaʻe o ka huahana.
1.5 Ka maloʻo a me ka ʻohi ʻana
Ma hope o ka holoi ʻana, loaʻa i ka HEMC ka mākū nui a pono e hoʻomaloʻo ʻia. ʻO nā ʻano hana hoʻomaloʻo maʻamau:
ʻO ka hoʻomaloʻo ʻana o ka ea: e hoʻohana ana i ka ea wela kiʻekiʻe e hoʻomaloʻo i ka HEMC pulu, me ka hana kiʻekiʻe a kūpono no ka hana nui.
ʻO ka maloʻo maloʻo: ka hoʻomehana a me ka maloʻo ma lalo o ka haʻahaʻa haʻahaʻa haʻahaʻa, hiki ke pale pono i ka cellulose degradation a kūpono i nā huahana kiʻekiʻe.
Ma hope o ka maloʻo ʻana, ʻoki ʻia ka HEMC e kahi pulverizer a hoʻomalu ʻia ka nui o ka ʻāpana e ka nānā ʻana e hoʻokō i ka maikaʻi o ka huahana (maʻamau 80-120 mesh).
2. Ka hoomalu maikai
ʻO ka mana maikaʻi o HEMC ka mea nui i nā hōʻailona aʻe:
Degree of substitution (DS and MS): hoʻoholo i ka solubility a me ka viscosity, ʻo DS ma waena o 1.1-2.0 a ʻo MS ma waena o 0.1-0.5.
ʻO ka wai maʻemaʻe: makemake pinepine ʻia≤5%.
Viscosity: koi ʻia nā māka viscosity ʻokoʻa no nā kahua noi like ʻole (e like me 400-100,000 mPa·s).
Maʻemaʻe: pono haʻahaʻa lehu maʻiʻo, ka wehe ʻana i nā koena solvents, a hōʻoia i ka ʻala ʻole.
3. Nā wahi noi nui
ʻO nā mea kūkulu hale: hoʻohana ʻia i ka mortar sima, ka pauka putty, ka mea hoʻopili tile, e hoʻomaikaʻi i ka mālama ʻana i ka wai a me ka hana hana.
ʻOihana uhi: hoʻohana ʻia i ka pena latex a me ka pena, e hāʻawi i ka rheology maikaʻi a me ka hana anti-sagging.
ʻO ka lāʻau lapaʻau a me ka meaʻai: ma ke ʻano he mānoanoa a me ka emulsifier, e like me nā kūlana meaʻai a i ʻole pharmacopoeia.
ʻO kaHEMC ʻO ke kaʻina hana e pili ana i ka alkalization, etherification, neutralization, holoi, maloʻo a me ka ʻoki ʻana. ʻO ka hoʻonui ʻana i nā ʻāpana kaʻina hana a me ka hoʻomaikaʻi ʻana i ke degere pani a me ka maʻemaʻe o ka huahana nā kī i ka hoʻomaikaʻi ʻana i ka hana HEMC. Me ka hoʻonui ʻana i nā koi no ka mālama ʻana i ke kaiapuni a me ka hana ʻōmaʻomaʻo, ʻoi aku ka nānā ʻana o ka hana HEMC i ka mālama ʻana i ka ikehu a me ka hoʻemi ʻana o ka hoʻokuʻu ʻana a me ka hoʻohana ʻana i nā solvents ʻōmaʻomaʻo i ka wā e hiki mai ana.
Ka manawa hoʻouna: Mei-08-2025