Focus on Cellulose ethers

Njirimara HPMC Hydroxypropyl Methyl Cellulose

Hydroxypropyl methylcellulose HPMC bụ ụdị nke na-abụghị ionic cellulose agwakọta ether. Dị iche na ionic methyl carboxymethyl cellulose agwakọta ether, ọ dịghị emeghachi omume na arọ ọla. N'ihi nha dị iche iche nke ọdịnaya methylcellulose na hydroxypropyl dị na hydroxypropyl methylcellulose na viscosities dị iche iche, e nwere ọtụtụ ụdị nwere ihe dị iche iche, dịka ọmụmaatụ, ọdịnaya methoxyl dị elu na obere ọdịnaya hydroxypropyl Ọrụ ya dị nso na nke methyl cellulose, ebe arụmọrụ nke Ọdịnaya methoxy dị ala yana ọdịnaya hydroxypropyl dị elu dị nso na nke hydroxypropyl methyl cellulose. Otú ọ dị, n'ụdị ọ bụla, ọ bụ ezie na ọ bụ naanị obere hydroxypropyl otu ma ọ bụ obere methoxyl dị n'ime ya, solubility na organic solvents ma ọ bụ flocculation okpomọkụ na aqueous ngwọta dị nnọọ iche.
 
1. Ihe solubility nke hydroxypropyl methylcellulose
① Solubility nke hydroxypropyl methylcellulose na mmiri Hydroxypropyl methylcellulose bụ n'ezie ụdị methylcellulose gbanwetụrụ site propylene oxide (methoxypropylene), n'ihi ya, ọ ka nwere otu ihe onwunwe dị ka methyl cellulose Cellulose nwere yiri àgwà nke mmiri oyi solubility na mmiri ọkụ insolubility. Otú ọ dị, n'ihi otu hydroxypropyl a gbanwere, okpomọkụ gelation ya na mmiri ọkụ dị elu karịa nke methyl cellulose. Dịka ọmụmaatụ, viscosity nke hydroxypropyl methylcellulose aqueous solution na 2% methoxy ọdịnaya nnọchi ogo DS=0.73 na hydroxypropyl ọdịnaya MS=0.46 bụ ngwaahịa nke 500mpa?s na 20°C, na gel okpomọkụ Ọ nwere ike iru nso 100° C, ebe methyl cellulose n'otu okpomọkụ dị naanị ihe dịka 55 Celsius. N'ihe gbasara mgbaze ya na mmiri, a na-emeziwanye ya nke ọma. Dị ka ihe atụ, na pulverized hydroxypropyl methylcellulose (a ngwaahịa na a urughuru size nke 0.2 ~ 0.5mm na a 4% aqueous ngwọta viscosity nke 2pa?s na 20 Celsius C nwere ike zụrụ na ụlọ okpomọkụ, ọ bụ mfe soluble na mmiri na-enweghị jụrụ oyi. .
 
② Solubility nke hydroxypropyl methylcellulose na organic solvents The solubility nke hydroxypropyl methylcellulose na organic solvents dịkwa mma karịa nke methylcellulose. Maka ngwaahịa karịrị 2.1,nnukwu viscosity hydroxypropyl methylcellulosenwere hydroxypropyl MS = 1.5 ~ 1.8 na methoxy DS = 0.2 ~ 1.0, na ngụkọta ogo nke nnọchi n'elu 1.8, bụ soluble na anhydrous methanol na ethanol ngwọta Ọkara, na thermoplastic na mmiri-soluble. Ọ na-agbaze na chlorinated hydrocarbons dị ka methylene chloride na chloroform, na organic mgbaze dị ka acetone, isopropanol na diacetone mmanya. Ya solubility na organic solvents dị mma karịa mmiri solubility.
 
2. Ihe ndị na-emetụta viscosity nke hydroxypropyl methylcellulose
Ihe na-emetụta viscosity nke Hydroxypropyl Methyl Cellulose Nchọpụta viscosity ọkọlọtọ nke hydroxypropyl methyl cellulose bụ otu ihe ahụ dị ka nke ethers cellulose ndị ọzọ. A na-atụ ya na 20 Celsius na ngwọta mmiri 2% dị ka ọkọlọtọ. Viscosity nke otu ngwaahịa na-abawanye na mmụba nke itinye uche. Maka ngwaahịa ndị nwere nha molekụla dị iche iche n'otu ntinye uche, ngwaahịa ahụ nwere ibu arọ molekul nwere nnukwu viscosity. Mmekọrịta ya na okpomọkụ yiri nke methyl cellulose. Mgbe okpomọkụ na-ebili, viscosity na-amalite ibelata, ma mgbe ọ ruru ụfọdụ okpomọkụ, viscosity na-ebili na mberede na gelation pụtara. Igwe ọkụ gel nke ngwaahịa viscosity dị ala dị elu. dị elu. Ebe gel ya abụghị naanị ihe jikọrọ ya na viscosity nke ether, kamakwa ọ metụtara nhazi nke otu metoxyl na otu hydroxypropyl na ether na nha nke ogo nnọchi anya zuru oke. A ghaghị iburu n'uche na hydroxypropyl methylcellulose bụkwa pseudoplastic, na ngwọta ya kwụsiri ike na ụlọ okpomọkụ na-enweghị mmebi ọ bụla na viscosity ma e wezụga n'ihi na enwere ike imebi enzymatic.
 
3. Hydroxypropyl methylcellulose na-eguzogide acid na alkali
Hydroxypropyl methylcellulose acid na alkali eguzogide Hydroxypropyl methylcellulose bụ n'ozuzu ike na acids na alkalis, ọ dịghị emetụta na nso nke pH 2 ~ 12. Ọ nwere ike iguzogide ụfọdụ ihe ọkụ ọkụ, dị ka formic acid, acetic acid, citric acid, succinic acid, phosphoric acid, boric acid, wdg. Ma acid concentrated nwere mmetụta nke ibelata viscosity. Alkalis dị ka caustic soda, caustic potash na mmiri lime enweghị mmetụta na ya, mana ha nwere ike ịbawanye viscosity nke ngwọta ahụ ntakịrị, wee jiri nwayọọ nwayọọ belata ya.
 
4. The miscibility nke hydroxypropyl methylcellulose
Enwere ike ịgwakọta ihe ngwọta nke hydroxypropyl methylcellulose Hydroxypropyl methylcellulose na ogige polymer nke nwere ike ịsacha mmiri ka ọ bụrụ ihe ngwọta edo na nke doro anya na viscosity dị elu. Ogige ndị a polymer gụnyere polyethylene glycol, polyvinyl acetate, polysilicon, polymethylvinylsiloxane, hydroxyethyl cellulose, na methyl cellulose. Ogige molekul dị elu dị ka chịngọm arabic, chịngọm igurube, karaya chịngọm, wdg nwekwara ezigbo ndakọrịta na ngwọta ya. Hydroxypropyl methylcellulose nwekwara ike jikọta ya na mannitol ester ma ọ bụ sorbitol ester nke stearic acid ma ọ bụ palmitic acid, ma nwee ike jikọta ya na glycerin, sorbitol na mannitol, a pụkwara iji ogige ndị a mee ihe dị ka hydroxypropyl methylcellulose Plasticizer maka cellulose.
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5. Insolubilization na mmiri solubility nke hydroxypropyl methylcellulose
Ethers cellulose na-adịghị edozi mmiri nke na-adịghị edozi mmiri nke hydroxypropyl methylcellulose nwere ike jikọta ya na aldehydes n'elu, nke mere na ethers ndị a na-eme ka mmiri na-agbanye na ngwọta na-aghọ ihe na-adịghị edozi na mmiri. Aldehydes nke na-eme hydroxypropyl methylcellulose insoluble gụnyere formaldehyde, glyoxal, succinic aldehyde, adipaldehyde, wdg Mgbe ị na-eji formaldehyde, a ga-akwụ ụgwọ nlebara anya pụrụ iche na pH uru nke ngwọta, n'etiti nke glioxal na-emeghachi ngwa ngwa , ya mere, a na-ejikarị glioxal eme ihe dị ka crosslinking. onye nnọchi anya na mmepụta ụlọ ọrụ. Ọnụ ego nke ụdị onye na-ejikọta ọnụ na ngwọta bụ 0.2% ~ 10% nke oke ether, ọkacha mma 7% ~ 10%, dịka ọmụmaatụ, 3.3% ~ 6% nke glioxal bụ ihe kacha mma. The izugbe ọgwụgwọ okpomọkụ bụ 0 ~ 30 ℃, na oge bụ 1 ~ 120min. A ghaghị ime mmeghachi omume na-ejikọta ya n'okpuru ọnọdụ acidic. N'ozuzu, a na-ebu ụzọ tinye ngwọta ya na inorganic siri ike acid ma ọ bụ organic carboxylic acid iji dozie pH nke ngwọta na ihe dịka 2 ~ 6, ọkacha mma n'etiti 4 ~ 6, wee tinye aldehydes iji mee mmeghachi omume na-ejikọta ya. Acid eji eme ihe nwere hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxyacetic acid, succinic acid ma ọ bụ citric acid wdg, ebe enwere ike iji formic acid ma ọ bụ acetic acid, yana formic acid kacha mma. A nwekwara ike ịgbakwunye acid na aldehyde n'otu oge iji mee ka ngwọta ahụ nweta mmeghachi omume na-ejikọta n'ime oke pH chọrọ. A na-ejikarị mmeghachi omume a eme ihe na usoro ọgwụgwọ ikpeazụ na usoro nkwadebe nke cellulose ethers. Mgbe ether cellulose na-esighi ike, ọ dị mma ịsacha ma mee ka mmiri dị ọcha na 20 ~ 25 ° C. Mgbe a na-eji ngwaahịa ahụ eme ihe, enwere ike ịgbakwunye ihe ndị na-edozi ahụ na ngwọta nke ngwaahịa ahụ iji dozie pH nke ngwọta ahụ ka ọ bụrụ alkaline, ngwaahịa ahụ ga-agbaze na ngwọta ngwa ngwa. Usoro a na-emetụtakwa ọgwụgwọ nke ihe nkiri ahụ mgbe e mere ihe ngwọta cellulose ether ka ọ bụrụ ihe nkiri na-eme ka ọ bụrụ ihe nkiri na-adịghị edozi.
 
6. Enzyme eguzogide hydroxypropyl methylcellulose
Nguzogide enzyme nke hydroxypropyl methylcellulose bụ usoro mkpụrụ ndụ cellulose, dị ka otu anhydroglucose ọ bụla, ma ọ bụrụ na e nwere otu nnọchi nke nwere njikọ siri ike, ọ dịghị mfe ibute nje site na microorganisms, mana n'eziokwu ngwaahịa emechara mgbe uru nnọchi karịrị 1, ọ A ga-ewedakwa enzymes, nke pụtara na ogo nke nnọchi nke otu ọ bụla na agbụ cellulose ezughị oke, na microorganisms nwere ike imebi na otu anhydroglucose na-edochighị anya na-etolite shuga , dị ka nri maka microorganisms na-amịkọrọ. Ya mere, ọ bụrụ na ogo nke etherification nnọchi nke cellulose na-abawanye, nguzogide enzymatic nke cellulose ether ga-abawanye. Dị ka akụkọ si kwuo, n'okpuru ọnọdụ a na-achịkwa, nsonaazụ hydrolysis nke enzymes, viscosity nke hydroxypropyl methylcellulose (DS=1.9) bụ 13.2%, methylcellulose (DS=1.83) bụ 7.3%, methylcellulose (DS=1.66) bụ 3.8%, na hydroxyethyl cellulose bụ 1.7%. Enwere ike ịhụ na hydroxypropyl methylcellulose nwere ikike mgbochi enzyme siri ike. Ya mere, a na-eji ihe mkpuchi dị mma nke enzyme hydroxypropyl methylcellulose, jikọtara ya na mgbasa ozi dị mma, nke na-emepụta ihe na ihe nkiri, na-eji mkpuchi mmiri-emulsion, wdg, na n'ozuzu ọ dịghị mkpa ịgbakwunye ihe nchekwa. Otú ọ dị, maka nchekwa ogologo oge nke ngwọta ma ọ bụ mmetọ nwere ike site n'èzí, a pụrụ ịgbakwunye ihe nchekwa dị ka ihe nchebe, na nhọrọ nwere ike ikpebi dịka ihe ikpeazụ chọrọ nke ngwọta ahụ. Phenylmercuric acetate na manganese fluorosilicate bụ ihe nchebe dị irè, ma ha niile nwere Nsi, a ghaghị ilebara anya na ọrụ ahụ. N'ozuzu, 1 ~ 5mg nke phenylmercury acetate nwere ike ịgbakwunye na ngwọta kwa liter nke usoro onunu ogwu.
 
7. Arụ ọrụ nke hydroxypropyl methylcellulose membrane
Arụmọrụ nke ihe nkiri hydroxypropyl methylcellulose Hydroxypropyl methylcellulose nwere ọmarịcha ihe na-emepụta ihe nkiri. A na-ekpuchi ihe ngwọta mmiri ya ma ọ bụ ihe ngwọta nke organic na efere iko, ọ na-aghọkwa enweghị agba na nghọta mgbe ihichachara. Na ihe nkiri siri ike. Ọ nwere ezigbo nguzogide mmiri ma na-anọgidesi ike na oke okpomọkụ. Ọ bụrụ na agbakwunyere plasticizer hygroscopic, elongation na mgbanwe ya nwere ike ịkwalite. N'ihe gbasara imeziwanye mgbanwe, plasticizers dị ka glycerin na sorbitol kacha mma. N'ozuzu, ihe ngwọta ngwọta bụ 2% ~ 3%, na ego nke plasticizer bụ 10% ~ 20% nke cellulose ether. Ọ bụrụ na ọdịnaya nke plasticizer dị oke elu, colloidal dehydration shrinkage ga-eme na oke iru mmiri. Ike ike nke ihe nkiri ahụ agbakwunyere na plasticizer dị nnọọ ukwuu karịa nke ahụ na-enweghị mgbakwunye, ma na-abawanye na mmụba nke ego agbakwunyere, na hygroscopicity nke ihe nkiri ahụ na-abawanye na ụba nke plasticizer.


Oge nzipu: Dec-19-2022
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