Cellulose ether bụ okwu n'ozuzu maka usoro ngwaahịa na-emepụta site na mmeghachi omume nke cellulose alkali na etherifying n'okpuru ọnọdụ ụfọdụ. Alkali cellulose na-anọchi anya dị iche iche etherifying ọrụ iji nweta dị iche iche cellulose ether. Dị ka ionization Njirimara nke nnọchi, cellulose ethers nwere ike kewaa ụzọ abụọ: ionic (dị ka carboxymethyl cellulose) na nonionic (dị ka methyl cellulose). Dị ka ụdị nnọchi, ether cellulose nwere ike kewaa monoether (dị ka methyl cellulose) na ngwakọta ether (dị ka hydroxypropyl methyl cellulose). Dị ka solubility dị iche iche si dị, enwere ike kewaa ya na mmiri solubility (dị ka hydroxyethyl cellulose) na organic mgbaze solubility (dị ka ethyl cellulose). Ngwa ngwa agwakọtara akpọnwụ akpọnwụ akpọnwụ akpọnwụ bụ cellulose na-agbaze mmiri, na cellulose nke nwere ike ịsọpu mmiri na-ekewa n'ụdị ozugbo na ụdị mgbaze na-egbu oge n'elu.
Usoro ọrụ nke cellulose ether na ngwa agha bụ ndị a:
(1) Mgbe ether cellulose dị na ngwa agha gbazere n'ime mmiri, a na-eme ka nkesa dị irè na nke dị n'otu nke cimentious ihe dị na usoro ahụ n'ihi ọrụ elu, na ether cellulose, dị ka colloid nchebe, "na-ekpuchi" ihe siri ike. A na-emepụta ihe na-eme ka ihe nkiri na-egbuke egbuke na-emepụta ihe nkiri na-egbuke egbuke n'elu elu ya, nke na-eme ka usoro ngwa agha dịkwuo mma, ma na-eme ka mmiri dị nro nke ngwa agha ahụ dịkwuo mma n'oge usoro ngwakọta na ire ụtọ nke ihe owuwu.
(2) N'ihi njirimara nhazi nke ya, ihe ngwọta cellulose ether na-eme ka mmiri dị na ngwa ngwa ghara ịdị mfe, ma jiri nwayọọ nwayọọ hapụ ya ogologo oge, na-enye ngwa agha ahụ nke ọma na njide mmiri na ịrụ ọrụ.
1. Methylcellulose: (MC)
Mgbe ejiri alkali mesoo owu a nụchara anụcha, a na-emepụta cellulose ether site na mmeghachi omume nke methane chloride dị ka onye na-emepụta ihe. N'ozuzu, ogo nke nnọchi bụ 1.6 ~ 2.0, na solubility dịkwa iche na ọkwa dị iche iche nke nnọchi. Ọ bụ nke cellulose ether na-abụghị ionic.
(1) Methylcellulose na-agbaze na mmiri oyi, ọ ga-esikwa ike igbari na mmiri ọkụ. Ihe ngwọta ya na-edozi ahụ kwụsiri ike na pH = 3 ~ 12. Ọ nwere ezigbo ndakọrịta na starch, guar gum, wdg na ọtụtụ surfactants. Mgbe okpomọkụ na-erute okpomọkụ gelation, gelation na-eme.
(2) Njide mmiri nke methyl cellulose na-adabere na ego mgbakwunye ya, viscosity, urughuru mma na mgbasa ozi. N'ozuzu, ọ bụrụ na ego mgbakwunye buru ibu, ịdị mma dị ntakịrị, na viscosity dị ukwuu, ọnụ ọgụgụ njide mmiri dị elu. N'ime ha, ọnụ ọgụgụ nke mgbakwunye na-enwe mmetụta kachasị ukwuu na njide mmiri, na ọkwa nke viscosity adịghị adabere kpọmkwem na ọkwa nke njide mmiri. The mgbasa ọnụego tumadi na-adabere n'ókè nke elu mgbanwe nke cellulose ahụ na urughuru fineness. N'ime cellulose ethers dị n'elu, methyl cellulose na hydroxypropyl methyl cellulose nwere ọnụ ọgụgụ njide mmiri dị elu.
(3) Mgbanwe na okpomọkụ ga-emetụta oke njide mmiri nke methyl cellulose. N'ozuzu, ka okpomọkụ dị elu, na-akawanye njọ njigide mmiri. Ọ bụrụ na okpomọkụ nke ngwa agha gafere 40 Celsius, njide mmiri nke methyl cellulose ga-ebelata nke ukwuu, na-emetụta nrụnye ngwa ngwa.
(4) Methyl cellulose na-enwe mmetụta dị ukwuu n'ịrụ ụlọ na njikọta nke ngwa agha. “Nrapagide” ebe a na-ezo aka n'ike njikọ a na-enwe n'etiti ngwa ngwa onye ọrụ na mkpụrụ mgbidi ahụ, ya bụ, nkwụsi ike nke ngwa agha ahụ. Nchikota dị elu, nkwụsị nke mgbochi nke ngwa agha dị ukwuu, na ike nke ndị ọrụ na-arụ ọrụ na-arụ ọrụ na-arụkwa ọrụ buru ibu, na ịrụ ọrụ nke ngwa agha adịghị mma. Njikọ nke methyl cellulose dị n'ogo ọkara na ngwaahịa ether cellulose.
2. Hydroxypropyl methyl cellulose (HPMC):
Hydroxypropyl methylcellulose bụ ụdị cellulose nke mmepụta na oriri ya na-abawanye ngwa ngwa n'afọ ndị na-adịbeghị anya. Ọ bụ ether na-abụghị ionic cellulose agwakọta nke sitere na owu a nụchara anụcha mgbe alkalization, na-eji propylene oxide na methyl chloride dị ka onye na-ahụ maka etherification, site na usoro mmeghachi omume. Ogo nke nnọchi bụ n'ozuzu 1.2 ~ 2.0. Ngwongwo ya na-adịgasị iche dabere n'oke ọdịnaya methoxyl na ọdịnaya hydroxypropyl.
(1) Hydroxypropyl methylcellulose na-adị mfe mgbaze na mmiri oyi, ọ ga-enwekwa ihe isi ike na igbari na mmiri ọkụ. Ma gelation okpomọkụ ya na mmiri ọkụ dị nnọọ elu karịa nke methyl cellulose. A na-emeziwanye ihe solubility na mmiri oyi ma e jiri ya tụnyere methyl cellulose.
(2) Viscosity nke hydroxypropyl methylcellulose na-ejikọta ya na arọ molekụla ya, na ibu ibu molekụla, otú ahụ ka viscosity dị elu. Okpomọkụ na-emetụtakwa viscosity ya, ka okpomọkụ na-abawanye, viscosity na-ebelata. Otú ọ dị, mmetụta nke elu viscosity ya na okpomọkụ dị ala karịa nke methyl cellulose. Ngwọta ya kwụsiri ike mgbe echekwara ya na ụlọ okpomọkụ.
(3) Njide mmiri nke hydroxypropyl methylcellulose na-adabere na ego mgbakwunye ya, viscosity, wdg, na ọnụ ọgụgụ njide mmiri ya n'okpuru otu ihe mgbakwunye ahụ dị elu karịa nke methyl cellulose.
(4) Hydroxypropyl methylcellulose kwụsiri ike na acid na alkali, na ngwọta mmiri ya kwụsiri ike na pH = 2 ~ 12. Caustic soda na mmiri lime enweghị mmetụta dị nta na arụmọrụ ya, mana alkali nwere ike mee ka mgbasa ya dị ngwa ma mee ka viscosity ya dịkwuo ntakịrị. Hydroxypropyl methylcellulose kwụsiri ike na nnu nkịtị, ma mgbe ntinye nke ngwọta nnu dị elu, viscosity nke hydroxypropyl methylcellulose ngwọta na-ebuli elu.
(5) Hydroxypropyl methylcellulose nwere ike ịgwakọta ya na mmiri-soluble polymer ogige na-etolite a edo na elu viscosity ngwọta. Dị ka mmanya polyvinyl, starch ether, chịngọm akwukwo nri, wdg.
(6) Hydroxypropyl methylcellulose nwere nguzogide enzyme dị mma karịa methylcellulose, na ohere nke mmebi enzymatic nke ngwọta ya dị ala karịa nke methylcellulose.
(7) Nrapanye nke hydroxypropyl methylcellulose na mgbidi ngwa agha dị elu karịa nke methylcellulose.
3. Hydroxyethyl cellulose (HEC):
A na-eme ya site na owu a nụchara anụcha na alkali, wee meghachi omume na ethylene oxide dị ka onye na-eme ka etherification na ọnụnọ acetone. Ogo nke nnọchi ya n'ozuzu bụ 1.5 ~ 2.0. Ọ nwere hydrophilicity siri ike ma dị mfe ịmịkọrọ mmiri.
(1) Hydroxyethyl cellulose bụ soluble na mmiri oyi, ma ọ na-esiri ike igbari na mmiri ọkụ. Ngwọta ya kwụsiri ike na oke okpomọkụ na-enweghị gelling. Enwere ike iji ya ogologo oge n'okpuru nnukwu okpomọkụ na ngwa agha, mana njide mmiri ya dị ala karịa nke methyl cellulose.
(2) Hydroxyethyl cellulose kwụsiri ike na acid izugbe na alkali. Alkali nwere ike mee ka mgbasa ya dịkwuo ngwa ma mee ka viscosity ya dịkwuo ntakịrị. Mgbasa ya na mmiri dị ntakịrị njọ karịa nke methyl cellulose na hydroxypropyl methyl cellulose. .
(3) Hydroxyethyl cellulose nwere ezigbo mgbochi sag arụmọrụ maka ngwa agha, ma ọ nwere ogologo oge na-azụ azụ maka ciment.
(4) Arụmọrụ nke hydroxyethyl cellulose nke ụfọdụ ụlọ ọrụ ụlọ na-emepụta dị ntakịrị ala karịa nke methyl cellulose n'ihi oke mmiri dị na ya na nnukwu ntụ ntụ.
4. Carboxymethyl cellulose (CMC):
A na-eme ether cellulose ionic site na eriri eke (owu, wdg) mgbe ọgwụgwọ alkali gasịrị, na-eji sodium monochloroacetate dị ka onye na-ahụ maka etherification, ma na-enweta usoro ọgwụgwọ mmeghachi omume. Ogo nke nnọchi n'ozuzu bụ 0.4 ~ 1.4, na ogo nke nnọchi na-emetụta arụmọrụ ya nke ukwuu.
(1) Carboxymethyl cellulose bụ ihe hygroscopic karịa, ọ ga-enwekwa mmiri karịa mgbe echekwara ya n'okpuru ọnọdụ izugbe.
(2) Carboxymethyl cellulose ngwọta mmiri agaghị emepụta gel, na viscosity ga-ebelata na mmụba nke okpomọkụ. Mgbe okpomọkụ gafere 50 Celsius, viscosity agaghị agbanwe agbanwe.
(3) PH na-emetụta nkwụsi ike ya nke ukwuu. N'ozuzu, enwere ike iji ya na ngwa ngwa gypsum, ma ọ bụghị n'igwe simenti. Mgbe nnukwu alkaline, ọ ga-efunahụ viscosity.
(4) Njide mmiri ya dị nnọọ ala karịa nke methyl cellulose. Ọ na-enwe mmetụta nkwụsịtụ na ngwa agha nke gypsum ma na-ebelata ike ya. Otú ọ dị, ọnụ ahịa carboxymethyl cellulose dị nnọọ ala karịa nke methyl cellulose.
Oge nzipu: Feb-27-2023