Methylcellulose (MC)
Usoro molekul nke methylcellulose (MC) bụ:
[C6H7O2(OH)3-h(OCH3)n\]x
Usoro mmepụta bụ ime cellulose ether site na usoro mmeghachi omume mgbe ejiri alkali gwọọ owu a nụchara anụcha, a na-ejikwa methyl chloride dị ka ihe na-eme ka etherification dị. N'ozuzu, ogo nke nnọchi bụ 1.6~2.0, ihe na-agbazekwa dịkwa iche na ọkwa dị iche iche nke nnọchi. Ọ bụ nke cellulose ether na-abụghị ionic.
Methylcellulose na-agbaze n'ime mmiri oyi, ọ ga-esikwa ike ịgbaze n'ime mmiri ọkụ. Mmiri mmiri ya na-adị nnọọ mma n'etiti pH = 3 ~ 12.
Ọ na-adakọ nke ọma na starch, guar gum, wdg. na ọtụtụ surfactants. Mgbe okpomọkụ ruru okpomọkụ gelation, gelation na-eme.
Mịltịkọ mmiri nke methylcellulose na-adabere na ọnụọgụ mgbakwunye ya, viscosity ya, ịdị mma nke ihe ndị dị na ya na ọnụego mgbaze ya.
N'ozuzu, ọ bụrụ na ọnụọgụ mgbakwunye buru ibu, nha ya pere mpe, nha ya buru ibu, ọnụego nchekwa mmiri dị elu. N'ime ha, ọnụọgụ mgbakwunye na-enwe mmetụta kachasị na ọnụego nchekwa mmiri, ọkwa nke viscosity adịghịkwa nhata kpọmkwem na ọkwa nchekwa mmiri. Ọnụego mgbaze na-adaberekarị na oke mgbanwe elu nke mkpụrụ ndụ cellulose na nha nha nke mkpụrụ ndụ.
N'ime ihe ndị dị n'ime cellulose ethers ndị a, methyl cellulose na hydroxypropyl methyl cellulose nwere oke mmiri dị elu.
Carboxymethylcellulose (CMC)
Carboxymethyl cellulose, nke a makwaara dị ka sodium carboxymethyl cellulose, nke a na-akpọkarị cellulose, cmc, wdg., bụ polima anionic linear, nnu sodium nke cellulose carboxylate, a na-emegharịkwa ya ma ghara ịgwụ agwụ. Ihe ndị e ji kemịkalụ mee.
A na-ejikarị ya eme ihe n'ụlọ ọrụ nchacha, ụlọ ọrụ nri na mmiri mmanụ, ego ejiri mee ihe ịchọ mma bụ naanị ihe dịka 1%.
A na-eji eriri eke (owu, wdg) eme ionic cellulose ether mgbe a gwọchara alkali, na-eji sodium monochloroacetate eme ihe dị ka ihe na-eme ka etherification dị, ma na-eme usoro ọgwụgwọ mmeghachi omume.
Ogo nnọchi anya na-abụkarị 0.4 ~ 1.4, arụmọrụ ya na-emetụtakwa nke ukwuu site na ogo nnọchi.
CMC nwere ikike njikọ dị mma, mmiri mmiri ya nwekwara ikike nkwụsịtụ dị mma, mana enweghị ezigbo uru mgbanwe plastik.
Mgbe CMC gbazere, depolymerization na-eme n'ezie. Viskọpụ ahụ na-amalite ịrị elu n'oge ịgbaze, na-agafe oke kachasị, wee daa n'elu ala. Viskọpụ ahụ na-esi na ya apụta metụtara depolymerization.
Oke nke depolymerization nwere njikọ chiri anya na ọnụọgụ nke ihe mgbaze na-adịghị mma (mmiri) dị na nhazi ahụ. N'ime sistemụ ihe mgbaze na-adịghị mma, dị ka ihe e ji asa ezé nke nwere glycerin na mmiri, CMC agaghị depolymerize kpamkpam ma ga-eru ebe nha nhata.
Ọ bụrụ na e nwee mmiri a na-etinye n'ime ya, ọ ga-adị mfe iwepụ CMC nke nwere hydrophilic karịa CMC nke nwere obere mgbanwe.
Hydroxyethylcellulose (HEC)
A na-eme HEC site n'iji alkali gwọọ owu a nụchara anụcha, wee meghachi omume na ethylene oxide dị ka ihe na-eme ka etherification dị n'ihu acetone. Ogo nnọchi ya na-abụkarị 1.5 ~ 2.0. O nwere hydrophilicity siri ike ma dịkwa mfe ịmịkọrọ mmiri.
A na-agbaze hydroxyethyl cellulose na mmiri oyi, mana ọ na-esiri ike ịgbaze na mmiri ọkụ. Mmiri ya na-adịgide adịgide n'oge okpomọkụ dị elu na-enweghị itching.
Ọ na-adịgide adịgide ruo na asịd na ntọala nkịtị. Alkalis nwere ike ime ka ọ gbazee ngwa ngwa ma mee ka ọ dịkwuo mma. Ọ na-agbaze n'ime mmiri dịtụ njọ karịa nke methyl cellulose na hydroxypropyl methyl cellulose.
Selulose Hydroxypropyl Methyl (HPMC)
Usoro molekul 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-amụba ngwa ngwa.
Ọ bụ ngwakọta ether nke na-abụghị ionic cellulose e ji owu a nụchara anụcha mee mgbe alkalization gasịrị, na-eji propylene oxide na methyl chloride dị ka ihe na-eme ka etherification dị, site na usoro mmeghachi omume. Ogo nke nnọchi na-abụkarị 1.2~2.0.
Njirimara ya dị iche iche n'ihi oke dị iche iche nke ọdịnaya methoxyl na ọdịnaya hydroxypropyl.
Hydroxypropyl methylcellulose na-agbaze ngwa ngwa na mmiri oyi, mana ọ ga-esiri ike ịgbaze na mmiri ọkụ. Mana okpomọkụ ya na-agbaze na mmiri ọkụ dị elu karịa nke methyl cellulose. A na-emekwa ka mmiri oyi na-agbaze nke ọma ma e jiri ya tụnyere methyl cellulose.
Ọbara hydroxypropyl methylcellulose na-adabere na ibu molekul ya, na ibu molekul ka ọ na-ebu, otú ahụ ka viscosity ya na-abawanye. Okpomọkụ na-emetụtakwa viscosity ya, ka okpomọkụ na-abawanye, viscosity na-ebelata. Agbanyeghị, viscosity ya dị elu nwere mmetụta okpomọkụ dị ala karịa methyl cellulose. Mmiri ya na-adịgide adịgide mgbe echekwara ya na okpomọkụ ụlọ.
Mmiri nke hydroxypropyl methylcellulose na-adabere na ọnụọgụ ya, viscosity, wdg, na ọnụego ya na-ejide mmiri n'otu ego mgbakwunye ahụ dị elu karịa nke methyl cellulose.
Hydroxypropyl methylcellulose na-adịgide adịgide site na asịd na alkali, mmiri mmiri ya na-adịkwa mma nke ukwuu n'etiti pH = 2 ~ 12. Caustic soda na mmiri lime anaghị emetụta arụmọrụ ya nke ọma, mana alkali nwere ike ime ka ọ gbazee ngwa ngwa ma mee ka ọ dị nro.
Hydroxypropyl methylcellulose anaghị agbanwe agbanwe dịka nnu nkịtị si dị, mana mgbe njupụta nke mmiri nnu dị elu, ọ na-agbawa agbawa nke mmiri hydroxypropyl methylcellulose.
Enwere ike ịgwakọta Hydroxypropyl methylcellulose na ngwakọta polima mmiri na-agbaze iji mepụta ngwọta viscosity dị otu ma dị elu. Dịka polyvinyl alcohol, starch ether, chịngọm akwụkwọ nri, wdg.
Hydroxypropyl methylcellulose nwere nguzogide enzyme ka mma karịa methylcellulose, ihe ngwọta ya adịghịkwa adị mfe imebi n'ụzọ enzyme karịa methylcellulose.
Oge ozi: Febụwarị-14-2023