Methyl Cellulose (MC) Molecular formula \[C6H7O2(OH)3-h(OCH3)n1] x A na-eji alkali na-agwọ owu a nụchara anụcha, a na-ejikwa methyl chloride mee ihe dị ka ihe etherification. Mgbe usoro mmeghachi omume gasịrị, a na-eme ọgwụgwọ cellulose ether. N'ozuzu, ogo nke nnọchi bụ 1.6 ~ 2.0, na ogo nke nnọchi dị iche. Ọ bụ nke cellulose ether na-abụghị ionic.
1. Methylcellulose bụ soluble na mmiri oyi, mmiri ọkụ ga-ezute ihe isi ike, na pH nso nke mmiri ngwọta dị nnọọ ike n'etiti 3/12. Starch, guar chịngọm na ọtụtụ ndị ọzọ surfactants na-dakọtara karịa. Gelation na-eme mgbe okpomọkụ na-erute okpomọkụ gelation.
Njide mmiri nke methylcellulose na-adabere na ego ya agbakwunyere, viscosity, urughuru mma na ọnụego mgbasa. Na-agbasawanye n'ozuzu, obere, nnukwu viscosity, nnukwu mmiri na-ejide. N'ime ha, njide mmiri na-enwe mmetụta kasịnụ, na ọkwa viscosity adịghị adabere kpọmkwem na njide mmiri. The mgbasa ọnụego tumadi na-adabere n'ókè nke elu mgbanwe nke cellulose ahụ na fineness nke ahụ. N'ime cellulose ethers dị n'elu, methyl cellulose na hydroxypropyl methyl cellulose nwere nnukwu njigide mmiri.
Mgbanwe okpomọkụ nwere ike imetụta njigide mmiri nke methyl cellulose. - Igwe ọkụ dị elu, nke ka njọ na 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.
Methylcellulose nwere mmetụta dị ukwuu na arụ ọrụ na nrapado nke ngwa agha. “Arapara” ebe a na-ezo aka nchikota n'etiti ngwa ngwa onye ọrụ na mkpụrụ mgbidi, ya bụ, nkwụsi ike nke ngwa agha ahụ. Viscosity, ngwa agha shie ike, na ike nke ndị ọrụ na-arụ ọrụ na-achọkwa nnukwu nnukwu, ịrụkwa ngwa ngwa adịghị mma. Methylcellulose na-arapara n'ọkwa na-agafeghị oke na ngwaahịa ether cellulose.
2. Hydroxypropyl methylcellulose (HPMC) [C 6 H 7 O 2 (OH) 3-mn (OCH 3) m, OCH 2 CH (OH) CH 3] n]] hydroxypropyl methyl cellulose N'afọ ndị na-adịbeghị anya, ụdị cellulose nwere. mụbara ngwa ngwa. Ọ bụ ihe na-abụghị ionic cellulose agwakọta ether kwadebere site a usoro nke mmeghachi omume mgbe alkalization nke nụchara anụcha alkali owu, nke propylene oxide na methyl chloride na-eji dị ka etherification agents. Ọkwa nke nnọchi na-abụkarị 1.2/2.0. Ngwongwo ya na-adịgasị iche dabere n'oke ọdịnaya metoxyl na ọdịnaya hydroxypropyl.
1. A na-ekewa Hydroxypropyl methylcellulose n'ime ụdị ọkụ-agbaze na ụdị ngwa ngwa. Okpomọkụ gelation ya na mmiri ọkụ dị elu nke ukwuu karịa nke methylcellulose. Ọ na-egosikwa mmụba dị ukwuu karịa methylcellulose mgbe agbazere na mmiri oyi.
Viscosity nke hydroxypropyl methylcellulose metụtara ịdị arọ molekụla, na ịdị arọ molekụla dị elu. Okpomọkụ na-emetụtakwa viscosity ya, ka okpomọkụ na-abawanye, viscosity na-ebelata. Otú ọ dị, mmetụta okpomọkụ na viscosity dị ala karịa nke methyl cellulose. Ihe ngwọta bụ nchekwa kwụsiri ike na ụlọ okpomọkụ.
3. Njide mmiri nke hydroxypropyl methylcellulose na-adabere na ego mgbakwunye ya, viscosity, wdg, na ọnụ ọgụgụ njide mmiri nke otu ego dị elu karịa nke methyl cellulose.
4. Hydroxypropyl methylcellulose kwụsiri ike na acid na alkali, na mmiri mmiri ngwọta ya dị nnọọ ike na pH nso nke 2/12. Ịrụ ọrụ nke soda caustic na mmiri lime adịghị enwe mmetụta dị ukwuu, ma alkali nwere ike mee ka ọnụego mgbasa ya dịkwuo elu, na viscosity na-abawanye. Hydroxypropyl methylcellulose kwụsiri ike na nnu nkịtị, ma mgbe ntinye nke ngwọta nnu dị elu, viscosity nke hydroxypropyl methylcellulose ngwọta na-emekarị ka ọ dịkwuo elu.
Enwere ike ịgwakọta Hydroxypropyl methylcellulose na polymers na-agbaze mmiri iji mepụta otu otu, ngwọta viscosity dị elu. Dị ka mmanya polyvinyl, starch ether, chịngọm akwukwo nri, wdg.
Hydroxypropyl methylcellulose nwere nguzogide enzyme dị mma karịa methylcellulose, ohere nke mmebi enzymatic nke ngwọta ya dị ala karịa nke methylcellulose, na ntinye nke hydroxypropylmethylcellulose na mgbidi ngwa agha dị elu karịa nke methylcellulose. isi cellulose.
Atọ, hydroxyethyl cellulose (HEC) na-eme site na owu a nụchara anụcha nke a na-eji alkali, n'ihu acetone, na ethylene oxide dị ka onye na-emepụta ihe. Ogo ngbanwe ya na-abụkarị 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 ahụ kwụsiri ike na oke okpomọkụ ma ọ nweghị ihe gel. Enwere ike iji ya ogologo oge na ngwa agha dị elu, mana njide mmiri ya dị ala karịa nke methyl cellulose.
2. Hydroxyethyl cellulose kwụsiri ike na n'ozuzu acid na alkali. Alkali na-eme ka mgbasa ya dịkwuo elu, na viscosity ya na-abawanye ntakịrị. Mgbasa ya na mmiri dị ntakịrị njọ karịa nke methyl cellulose na hydroxypropyl methyl cellulose.
3. Hydroxyethyl cellulose nwere ezigbo mgbochi nghọta arụmọrụ na ngwa agha, ma ruo ogologo oge, ụfọdụ domestically emepụta hydroxyethyl cellulose nwere budata ala arụmọrụ karịa methyl cellulose ruru ya nnukwu mmiri ọdịnaya na elu uyi ọdịnaya.
4. Carboxymethyl cellulose (CMC) \ [C6H7O2 (OH) 2och2COONa] (owu, wdg) nke eke eriri na-emeso ya na alkali, na sodium chloroacetate na-eji dị ka etherification ihe, mgbe usoro nke mmeghachi omume ọgwụgwọ, ọ na-mere n'ime ionic. cellulose ether. Ogo nke nnọchi bụ n'ozuzu 0.4/1.4, na ogo nke nnọchi nwere mmetụta ka ukwuu na arụmọrụ.
Carboxymethyl cellulose nwere nnukwu hygroscopicity, na ọnọdụ nchekwa n'ozuzu nwere ọtụtụ mmiri.
2. Carboxymethyl cellulose aqueous ngwọta adịghị emepụta gel, viscosity na-ebelata mgbe okpomọkụ na-ebili, na viscosity na-apụghị ịgbagha agbagha mgbe okpomọkụ gafere 50 ° C.
Nkwụsi ike ya na-emetụta pH nke ukwuu. A na-ejikarị gypsum mortar, ọ bụghị maka ngwa ngwa ciment. N'ihe banyere nnukwu alkalinity, ọ ga-efunahụ viscosity ya.
Njide mmiri ya dị nnọọ ala karịa nke methyl cellulose. Ngwa ngwa gypsum nwere mmetụta azụ azụ, na-ebelata ike. Ma ọnụ ahịa carboxymethyl cellulose dị nnọọ ala karịa nke methyl cellulose.
Oge nzipu: Jan-13-2023