Methylcellulose (MC)
Usoro ihe omimi nke methylcellulose (MC) bụ:
[C6H7O2(OH)3-h(OCH3)n\]x
Usoro mmepụta bụ ime cellulose ether site na mmeghachi omume dị iche iche mgbe a na-edozi owu a nụchara anụcha na alkali, a na-ejikwa methyl chloride mee ihe 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.
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.
Njide mmiri nke methylcellulose na-adabere na ego mgbakwunye ya, viscosity, urughuru mma na ọnụego mgbasa.
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.
Carboxymethylcellulose (CMC)
Carboxymethyl cellulose, nke a makwaara dị ka sodium carboxymethyl cellulose, nke a na-akpọkarị cellulose, cmc, wdg, bụ polymer linear anionic, nnu sodium nke cellulose carboxylate, na-emegharị ọhụrụ na nke na-adịghị agwụ agwụ. Ngwa ngwa kemịkalụ.
A na-ejikarị ya na ụlọ ọrụ nchacha, ụlọ ọrụ nri na mmiri na-egwu mmiri n'ubi mmanụ, ego a na-eji na ịchọ mma bụ naanị ihe dịka 1%.
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.
CMC nwere ikike ijikọ nke ọma, na ngwọta mmiri ya nwere ikike nkwụsịtụ dị mma, mana ọ nweghị ezigbo uru nrụrụ plastik.
Mgbe CMC gbazere, nkwụsịtụ na-eme n'ezie. Viscosity na-amalite ịrị elu n'oge mgbasa, na-agafe na nke kachasị, wee daa n'ala dị larịị. Ihe na-akpata viscosity metụtara depolymerization.
Ogo nke depolymerization nwere njikọ chiri anya na oke ihe mgbaze na-adịghị mma (mmiri) na nhazi ahụ. N'ime usoro ihe mgbaze na-adịghị mma, dị ka ntacha eze nwere glycerin na mmiri, CMC agaghị ewepụ kpamkpam ma rute ebe nha nha.
N'ihe banyere ntinye mmiri e nyere, CMC nke hydrophilic nke ukwuu dochie anya dị mfe karịa nke CMC dị ala dochie anya.
Hydroxyethylcellulose (HEC)
A na-eme HEC site n'ịgwọ 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 bụ n'ozuzu 1.5 ~ 2.0. Ọ nwere hydrophilicity siri ike ma dị mfe ịmịkọrọ mmiri.
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.
Ọ kwụsiri ike na acids na bases nkịtị. Alkalis 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.
Hydroxypropyl Methyl Cellulose (HPMC)
Usoro ihe omimi nke HPMC bụ:
\[C6H7O2(OH)3-mn(OCH3)m,OCH2CH(OH)CH3\]n\]x
Hydroxypropyl methylcellulose bụ ụdị cellulose nke mmepụta na oriri ya na-abawanye ngwa ngwa.
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 dị iche iche n'ihi oke dị iche iche nke ọdịnaya methoxyl na ọdịnaya hydroxypropyl.
Hydroxypropyl methylcellulose na-adị mfe mgbaze na mmiri oyi, mana ọ ga-esiri ya ike 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.
Viscosity nke hydroxypropyl methylcellulose na-ejikọta ya na ịdị arọ 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, nnukwu viscosity ya nwere mmetụta okpomọkụ dị ala karịa methyl cellulose. Ngwọta ya kwụsiri ike mgbe echekwara ya na ụlọ okpomọkụ.
Njide mmiri nke hydroxypropyl methylcellulose na-adabere na ego mgbakwunye ya, viscosity, wdg, na ọnụ ọgụgụ njide mmiri ya n'otu ego mgbakwunye dị elu karịa nke methyl cellulose.
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 elu.
Hydroxypropyl methylcellulose kwụsiri ike na nnu nkịtị, ma mgbe ntinye nke ngwọta nnu dị elu, viscosity nke hydroxypropyl methylcellulose ngwọta na-ebuli elu.
Enwere ike ịgwakọta Hydroxypropyl methylcellulose na ogige polymer na-agbaze mmiri iji mepụta otu ihe ngwọta na viscosity dị elu. Dị ka mmanya polyvinyl, starch ether, chịngọm akwukwo nri, wdg.
Hydroxypropyl methylcellulose nwere nguzogide enzyme dị mma karịa methylcellulose, na ngwọta ya adịkwaghị ka ọ ga-emebi enzymatically karịa methylcellulose.
Oge nzipu: Feb-14-2023