Kedu ka esi eme hydroxyethyl cellulose?

Hydroxyethyl Cellulose (HEC) bụ polymer mmiri na-agbaze nke ọma nke a na-ejikarị na kemịkalụ kwa ụbọchị, ihe owuwu, mkpuchi, ọgwụ, nri na ụlọ ọrụ ndị ọzọ. Ọ bụ ether cellulose nke na-abụghị ionic nke ejiri kemịkal gbanwee cellulose eke. Usoro mmepụta nke hydroxyethyl cellulose na-agụnye mmeghachi omume kemịkalụ mgbagwoju anya, gụnyere mmịpụta cellulose, ọgwụgwọ alkalization, mmeghachi omume etherification, wdg. Ihe na-esonụ bụ nkọwa zuru ezu na usoro mmepụta ya.

1. Nhọrọ nke akụrụngwa na mmịpụta nke cellulose
Isi akụrụngwa nke hydroxyethyl cellulose bụ cellulose eke, nke sitere na osisi, owu ma ọ bụ eriri osisi ndị ọzọ. Ọdịnaya cellulose dị na mgbidi cell osisi dị elu, na cellulose dị ọcha nwere ike isi na ihe ndị a sitere n'okike ma ọ bụ kemịkalụ nweta. Usoro mmịpụta na-agụnye ịkụpịa, iwepụ ihe ndị na-adịghị ọcha (dị ka lignin, hemicellulose), ịcha ọcha na usoro ndị ọzọ.

Mwepụta nke cellulose: A na-ejikarị cellulose eke eme ihe n'usoro ma ọ bụ kemịkalụ iji wepụ ihe ndị na-abụghị cellulose iji nweta cellulose dị ọcha. eriri owu, osisi pulp, wdg nwere ike ịbụ isi mmalite nke akụrụngwa. N'oge usoro ọgwụgwọ, a na-eji alkali (dị ka sodium hydroxide) na-enyere aka igbari ihe ndị na-abụghị cellulose, nke fọdụrụnụ bụ cellulose.
2. Ọgwụgwọ Alkalization
A ga-ebu ụzọ mee ka cellulose dị ọcha mee ihe. Nzọụkwụ a bụ ime ka ndị otu hydroxyl dị na cellulose molecular chain na-arụsi ọrụ ike ka ha wee nwee ike imeghachi omume ngwa ngwa site na onye na-emepụta ihe. Isi usoro nke ọgwụgwọ alkalisation bụ ndị a:

Mmeghachi omume nke cellulose na alkali: cellulose na-agwakọta ya na a siri ike alkali (na-emekarị sodium hydroxide) na-emepụta alkali cellulose (Alkali Cellulose). A na-emekarị usoro a na mmiri mmiri. Alkali cellulose bụ mmeghachi omume nke cellulose na sodium hydroxide. Ihe a nwere usoro dị nro na mmeghachi omume dị elu, nke na-eme ka mmeghachi omume etherification na-esote.
Usoro alkalization na-emekarị na okpomọkụ na iru mmiri kwesịrị ekwesị, na-emekarị na nso 20 ℃ ~ 30 ℃ ruo ọtụtụ awa iji hụ na otu hydroxyl dị na cellulose molecule na-arụ ọrụ nke ọma.

3. mmeghachi omume etherification
Etherification bụ isi nzọụkwụ na mmepụta nke hydroxyethyl cellulose. A na-emepụta hydroxyethyl cellulose site n'imeghachi alkali cellulose na ethylene oxide iji webata otu hydroxyethyl. Usoro ndị a kapịrị ọnụ bụ ndị a:

Mmeghachi omume na ethylene oxide: Alkali cellulose na-emeghachi omume na ụfọdụ ethylene oxide n'okpuru ụfọdụ ọnọdụ okpomọkụ na nrụgide. Ọdịdị mgbanaka dị na ethylene oxide na-emepe ka ọ bụrụ njikọ ether, na-emeghachi omume na otu hydroxyl dị na mkpụrụ ndụ cellulose, ma webata otu hydroxyethyl (-CH2CH2OH). Usoro a nwere ike gbanwee ogo nke etherification site na ịchịkwa ọnọdụ mmeghachi omume (dịka okpomọkụ, nrụgide, na oge).
A na-emekarị mmeghachi omume na mpaghara alkaline iji hụ na arụmọrụ etherification dị. The mmeghachi omume okpomọkụ bụ n'ozuzu 50 ℃ ~ 100 ℃, na mmeghachi omume oge bụ ọtụtụ awa. Site n'ịgbanwe ọnụọgụ ethylene oxide, enwere ike ịchịkwa ogo nke nnọchi nke ngwaahịa ikpeazụ, ya bụ, ole hydroxyl dị n'ime mkpụrụ ndụ cellulose na-eji otu hydroxyethyl dochie ya.

4. Neutralization na ịsacha
Mgbe emechara mmeghachi omume etherification, ihe ndị dị na alkaline na usoro mmeghachi omume kwesịrị ka a na-ewepụ ya. Ntụle ndị a na-ejikarị bụ ihe acidic, dị ka acetic acid ma ọ bụ hydrochloric acid. Usoro nkwụsịtụ ga-eme ka alkali gafere n'ime nnu, nke na-agaghị emetụta arụmọrụ nke ngwaahịa ahụ.

Mmeghachi omume nnọpụiche: Wepụ ngwaahịa ahụ na reactor wee gbakwunye acid kwesịrị ekwesị maka nnọpụiche ruo mgbe uru pH dị na sistemụ ahụ ruru nnọpụiche. Usoro a ọ bụghị nanị na-ewepụ alkali fọdụrụnụ, kamakwa ọ na-ebelata mmetụta nke mmeghachi omume sitere na ngwaahịa na arụmọrụ nke hydroxyethyl cellulose.

Ịsacha na akpịrị ịkpọ nkụ: Ekwesịrị ịsacha ngwaahịa a na-anọpụ iche ọtụtụ ugboro, na-ejikarị mmiri ma ọ bụ ethanol na ihe mgbaze ndị ọzọ na-ekpochapụ adịghị ọcha na ngwaahịa. Ngwaahịa a na-asachapụ na-agbaze site na centrifugation, nzacha nzacha na ụzọ ndị ọzọ iji belata ọdịnaya mmiri.

5. Ịkpọ nkụ na ịkụpịa
Mgbe ịsachara na akpịrị ịkpọ nkụ, hydroxyethyl cellulose ka nwere ntakịrị mmiri ma chọọ ka akpọnwụkwuo ya. Enwere ike ịme usoro ihicha site na ikpochapụ ikuku ma ọ bụ ihicha oghere iji hụ na ngwaahịa ahụ nwere nkwụsi ike dị mma n'oge nchekwa na ojiji.

Ịkpọ nkụ: Kpochapụ ngwaahịa ahụ na ọnọdụ okpomọkụ (na-adịkarị n'okpuru 60 Celsius) iji wepụ mmiri fọdụrụnụ. Okpomọkụ ihicha ekwesịghị ịdị elu, ma ọ bụghị ya, ọ nwere ike ịkpata mmebi ngwaahịa ma metụta ọrụ ya.

Nchicha na nyocha: Hydroxyethyl cellulose a mịrị amị na-adịkarị na ngọngọ ma ọ bụ lumps, a ga-egwepịa ya iji nweta ezigbo ntụ ntụ. The anuahade ngwaahịa na-kwesịrị ka ekpuchiri iji nweta urughuru size nkesa na-ezute chọrọ iji hụ na ya solubility na dispersibility na ngwa ngwa.

6. Nnwale na nkwakọ ngwaahịa ikpeazụ
Mgbe emechara, hydroxyethyl cellulose kwesịrị ka a nwalee maka ịdị mma iji hụ na ihe ngosi arụmọrụ ya na-emezu ụkpụrụ achọrọ. Ihe nnwale na-agụnyekarị:

Ntụle viscosity: viscosity nke hydroxyethyl cellulose mgbe agbazere n'ime mmiri bụ ihe ngosi mma dị mkpa, nke na-emetụta ojiji ya na mkpuchi, ihe owuwu, kemịkalụ kwa ụbọchị na mpaghara ndị ọzọ.
Ọdịnaya mmiri: Nyochaa ọdịnaya mmiri nke ngwaahịa ahụ iji hụ na nchekwa ya kwụsie ike.
Degree of nnọchi (DS) na molar nnọchi (MS): Kpebie ogo nke nnọchi na molar nnọchi n'ime ngwaahịa site na nyocha kemịkalụ iji hụ na mmetụta nke mmeghachi omume etherification.
Mgbe ị gafechara ule ahụ, a ga-etinye hydroxyethyl cellulose n'ime ntụ ntụ ma ọ bụ ngwaahịa granular, na-abụkarị na akpa rọba na-enweghị mmiri mmiri ma ọ bụ akpa akwụkwọ iji gbochie ya ka ọ ghara ikpori mmiri ma ọ bụ metọọ.

Usoro mmepụta nke hydroxyethyl cellulose na-agụnye usoro nke mmịpụta cellulose, ọgwụgwọ alkalization, mmeghachi omume etherification, neutralization na ịsacha, ihicha na ikpochapụ. Usoro dum na-adabere na alkalization na etherification na mmeghachi omume kemịkalụ, a na-enyekwa cellulose ezigbo mmiri solubility na ihe ndị na-emepụta ihe site na iwebata ìgwè hydroxyethyl. A na-eji hydroxyethyl cellulose mee ihe n'ọtụtụ ụlọ ọrụ, dị ka thickener maka mkpuchi, onye na-ejigide mmiri maka ihe owuwu ụlọ, onye na-eme ka ọ dị mma na ngwaahịa kemịkalụ kwa ụbọchị, wdg. Njikọ ọ bụla na usoro mmepụta kwesịrị ka a na-achịkwa ya nke ọma iji hụ na arụmọrụ dị elu ma kwụsie ike. nke ngwaahịa.