Focus on Cellulose ethers

Hydroxypropyl methylcellulose HPMC?

Hydroxypropyl methylcellulose HPMC bụ ihe na-abụghị ionic cellulose agwakọta ether dị iche iche agwakọta ethers na ionic methylcarboxymethylcellulose. Ọ naghị eji ọla dị arọ eme ihe. Ọdịiche dị na ọdịnaya nke hydroxypropyl methylcellulose, hydroxypropyl methylcellulose, na hydroxypropyl ọdịnaya ratio na viscosity nke mkpụrụ ndụ ihe nketa ikuku oxygen nwere ụdị dị iche iche n'ihe gbasara arụmọrụ. Dịka ọmụmaatụ, ụdị nwere ọdịnaya metxyl dị elu yana ọdịnaya hydroxypropyl dị ala nwere arụmọrụ dị iche iche. Na nso methylcellulose na ụdị ọdịnaya methoxy dị ala. E jiri ya tụnyere ụdị nwere ọdịnaya hydroxypropyl dị elu, arụmọrụ ya dị nso na nke hydroxypropyl methylcellulose emepụtara. Agbanyeghị, ọ bụ ezie na ụdị ọ bụla nwere naanị obere hydroxypropyl otu ma ọ bụ obere methoxy Group, enwere nnukwu ọdịiche dị na solubility na ihe mgbaze organic ma ọ bụ flocculation okpomọkụ na ngwọta mmiri.

 

1. Solubility nke hydroxypropyl methylcellulose

Solubility nke hydroxypropyl methylcellulose na mmiri Hydroxypropyl methylcellulose bụ n'ezie propylene oxide (methylhydroxypropyl ring) gbanwetụrụ methylcellulose, n'ihi ya, ọ ka nwere otu ihe onwunwe dị ka methylcellulose Ọ nwere ihe ndị yiri ya nke ịbụ soluble na mmiri oyi ma na-esighi ike na mmiri ọkụ. Otú ọ dị, okpomọkụ gelling nke hydroxypropyl gbanwetụrụ na mmiri ọkụ dị elu karịa nke methylcellulose. Dịka ọmụmaatụ, ngwọta mmiri 2% hydroxypropyl methylcellulose nwere ọdịnaya methoxy Group DS=0.73 yana ọdịnaya otu hydroxypropyl MS=0.46 nwere viscosity nke 500mpa na 20°C. Okpomọkụ gel nke ngwaahịa S dị nso na 100 Celsius, ebe nke methylcellulose n'otu ọnọdụ okpomọkụ dị naanị ihe dịka 55 Celsius. N'ihe gbasara solubility ya na mmiri, a na-emeziwanye ya nke ọma. Dị ka ihe atụ, mgbe hydroxypropyl methylcellulose na-echi ọnụ n'ala (na urughuru udi bụ 0.2 ~ 0.5mm, viscosity nke 4% mmiri na 20 Celsius C bụ 2pA·S, ọ nwere ike na-eji na ụlọ okpomọkụ na-enweghị jụrụ. mfe dissolves na mmiri).

 

(2) Solubility nke hydroxypropyl methylcellulose na organic solvents The solubility nke hydroxypropyl methylcellulose na organic solvents dịkwa mma karịa nke methylcellulose. Methylcellulose chọrọ akara ngbanwe methoxy nke 2.1 ngwaahịa ndị a dị n'elu nwere nnukwu viscosity hydroxypropyl methylcellulose na hydroxypropyl MS=1.5 ~ 1.8 na methoxy DS=0.2 ~ 1.0, yana ogo ngbanwe nke ihe karịrị 1.8, ma dịkwa mfe soluble na methan anhydrous. ethanol ngwọta. Thermoplastic na mmiri soluble. Ọ na-agbaze na chlorinated hydrocarbons dị ka methylene chloride na chloroform, na organic mgbaze dị ka acetone, isopropyl mmanya na diacetone mmanya. Ya solubility na organic solvents dị mma karịa mmiri solubility.

 

2. Ihe ndị na-emetụta viscosity nke hydroxypropyl methylcellulose

Hydroxypropyl methylcellulose viscosity factor ọkọlọtọ viscosity nke hydroxypropyl methylcellulose bụ otu ihe ahụ na cellulose ethers ndị ọzọ, a na-atụkwa na 20 Celsius C na 2% aqueous ngwọta dị ka ọkọlọtọ. Viscosity nke otu ngwaahịa na-abawanye ka ntinye uche na-abawanye. Maka ngwaahịa ndị nwere otu ntinye uche na ihe dị iche iche dị iche iche, ngwaahịa nwere nnukwu ibu molecular nwere nnukwu viscosity. Mmekọrịta ya na okpomọkụ yiri nke methylcellulose. Mgbe okpomọkụ na-ebili, viscosity na-amalite ibelata, ma mgbe ọ ruru ụfọdụ okpomọkụ, viscosity na-ebili na mberede na gelation pụtara. Ngwaahịa viscosity dị ala nwere okpomọkụ gelling dị elu karịa ngwaahịa viscosity dị elu. Ebe gel abụghị nanị ihe jikọrọ ya na viscosity nke ether, kamakwa ọ metụtara nhazi nke methoxy na hydroxypropyl dị na ether na ngụkọta nke nnọchi. Ọ ga-kwuru na hydroxypropyl methylcellulose bụkwa pseudoplastic; Ngwọta ya na-akwụsi ike mgbe echekwara ya na ụlọ okpomọkụ ma ghara igosi mbelata viscosity ọ bụla, belụsọ maka mmebi enzymatic enwere ike.

 

3. Hydroxypropyl methylcellulose bụ acid na alkali na-eguzogide ọgwụ

Hydroxypropyl methylcellulose bụ acid na alkali na-eguzogide ọgwụ. Hydroxypropyl methyl cellulose bụ acid na alkali na-eguzogide ọgwụ. Ọ kwụsiri ike n'ozuzu yana uru pH agaghị emetụta ya na oke PH2 ~ 12. Ọ nwere ike iguzogide ụfọdụ acid na-adịghị ike, dị ka formic acid, acetic acid, na lemon. Acid, succinic acid, phosphoric acid mana acid gbadoro anya nwere mmetụta nke ibelata viscosity. Alkali dị ka soda caustic, potassium caustic, na mmiri lime enweghị mmetụta na ya, mana mmetụta nke ịba ụba viscosity nke ngwọta ga-eji nwayọọ nwayọọ na-ebelata.

 

4. Hydroxypropyl methylcellulose nwere ike ịgwakọta

Enwere ike ịgwakọta ihe ngwọta Hydroxypropyl methylcellulose na ogige polymer mmiri na-agbaze iji mepụta otu ihe ngwọta na-enweghị atụ na viscosity dị elu. Ogige ndị a polymer gụnyere polyethylene glycol, polyvinyl acetate, polysiloxane, polymethyl vinyl siloxane, hydroxyethyl cellulose na methyl cellulose. Ogige polymer eke dị ka chịngọm acacia, chịngọm igurube, chịngọm igurube, wdg nwekwara ezigbo ngwakọta. ngwọta ya. Enwere ike ịgwakọta Hydroxypropyl methylcellulose na stearic acid ma ọ bụ mannitol palmitate ma ọ bụ sorbitol, a pụkwara ịgwakọta ya na glycerin, sorbitol na mannitol. Enwere ike iji ogige ndị a dị ka hydroxypropyl methylcellulose plasticizers agents.

 

5. Hydroxypropyl methylcellulose bụ ihe a na-adịghị ahụkebe na mmiri

Hydroxypropyl methylcellulose bụ ihe a na-adịghị ahụkebe na cellulose ethers nke mmiri na-agbaze ma nwee ike jikọta ya na aldehydes na-ejikọta ya na elu, na-eme ka ethers ndị a na-agbaze mmiri na-asọba na ngwọta wee ghọọ ihe na-adịghị ike na mmiri. Na mee ka hydroxypropyl methylcellulose na-adịghị ike na aldehydes, formaldehyde, glioxal, succinic acid, dialdehyde, wdg. Mgbe ị na-eji formaldehyde, a ga-akwụ ụgwọ nlebara anya pụrụ iche na pH uru nke ngwọta. N'ime ha, glycoxal na-emeghachi ngwa ngwa, ya mere a na-eji ya na ụlọ ọrụ Glyoxal na-ejikarị eme ihe dị ka onye na-ejikọta ọnụ na mmepụta. -Crosslinking nnọchiteanya. Usoro ọgwụgwọ nke ụdị onye na-emekọrịta ihe na-ejikọta ya na ngwọta bụ 0.2% ruo 10% nke oke ether, na nke kachasị mma bụ 7% ruo 10%. Ọ bụrụ na ejiri glycoxal, 3.3% ruo 6% dabara nke ọma. 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-agbakwunye acid siri ike ma ọ bụ organic carboxylic acid na ngwọta iji dozie pH nke ngwọta na ihe dịka 2 ruo 6, ọkacha mma n'etiti 4 na 6, mgbe ahụ, a na-agbakwunye aldehydes iji mee mmeghachi omume na-ejikọta ya. Acid ndị a na-eji gụnyere hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, glycolic acid, succinic acid ma ọ bụ citric acid, n'ime nke formic acid ma ọ bụ acetic acid kacha mma, na formic acid kacha mma. Acids na aldehydes nwekwara ike ịgbakwunye n'otu oge iji gafee njikọ ngwọta n'ime oke pH achọrọ. A na-ejikarị mmeghachi omume a eme ihe na njedebe ikpeazụ nke usoro nkwadebe cellulose ether iji mee ka cellulose ether ghara ịsacha ma kwado ịsacha na ịdị ọcha na mmiri 20 ~ 25 ° C. Mgbe ị na-eji ngwaahịa ahụ, ị ​​nwere ike ịgbakwunye ihe ndị na-edozi ahụ na ngwọta ngwaahịa iji dozie pH nke ngwọta ka ọ bụrụ alkaline ka ngwaahịa ahụ wee gbaze ngwa ngwa na ngwọta. A pụkwara iji usoro a mee ihe mgbe a na-akwadebe ihe nkiri site na iji cellulose ether ngwọta na mgbe ahụ, a na-edozi ihe nkiri ahụ ka ọ bụrụ ihe nkiri na-adịghị edozi.

 

6. Hydroxypropyl methylcellulose mgbochi-enzyme

Mwepụta nke cellulose nke hydroxypropyl methylcellulose na-eguzogide ọgwụ n'ụzọ doro anya. Dịka ọmụmaatụ, otu anhydroglucose nke ọ bụla na-ejikọta ya na otu ndị na-anọchi anya ya na ọ dịghị enwe ike ibute nje na nje microbial. Otú ọ dị, n'eziokwu, ngbanwe uru nke ngwaahịa emechara gafere 1. Ọ nwekwara ike imebi ya site na enzymes, nke na-egosi na ogo nke nnọchi nke otu ọ bụla na cellulose yinye bụ ihe na-adịghị mma, na microorganisms nwere ike imebi ndị dị nso anhydroglucose dị iche iche na-emepụtaghị. shuga, nke microorganisms nwere ike itinye ya dị ka nri. Ya mere, ọ bụrụ na ogo ether nnọchi nke cellulose na-abawanye, nguzogide nke cellulose ethers na ọgụ enzymatic ga-abawanye. A na-akọ na n'okpuru ọnọdụ a na-achịkwa, hydroxypropyl methylcellulose (DS=1.9), methylcellulose (DS=1.83), methylcellulose (DS=1.66), hydroxyethylcellulose (1.7%) Ihe ndị fọdụrụ na viscosities bụ 13.2%, 7.3%, 3.8% na 1.7% n'otu n'otu. Hydroxypropyl methylcellulose nwere ikike mgbochi enzyme siri ike. Enwere ike ịhụ na hydroxypropyl methylcellulose nwere nguzogide enzyme magburu onwe ya, yana mgbakwunye ya dị mma, ịgbasa na mmepụta ihe nkiri, enwere ike iji ya na mkpuchi emulsion, wdg, na n'ozuzu ọ dịghị achọ mgbakwunye nke ihe nchekwa. Otú ọ dị, iji gbochie ngwọta site na nchekwa ogologo oge ma ọ bụ mmetọ nke mpụga, enwere ike ịgbakwunye ihe nchekwa, na nhọrọ nke ihe nchekwa nwere ike ikpebi dabere na ihe ikpeazụ chọrọ nke ngwọta. Phenylmercuric acetate na manganese fluorosilicate bụ ihe nchekwa dị irè, mana ha na-egbu egbu na a ga-ejikwa nlezianya mee ya. N'ozuzu, 1 ruo 5 mg nke phenylmercuric acetate nwere ike ịgbakwunye na liter nke ngwọta ọ bụla.

 

7. Arụ ọrụ nke hydroxypropyl methylcellulose membrane

Ihe na-emepụta ihe nkiri Hydroxypropyl methylcellulose Hydroxypropyl methylcellulose nwere ezigbo ihe na-emepụta ihe nkiri. Mgbe a na-ekpuchi ihe ngwọta mmiri ya ma ọ bụ ihe ngwọta organic na efere iko, ọ na-aghọ ihe nkiri na-enweghị agba, nke na-egbuke egbuke na nke siri ike mgbe ihichachara. . Ọ nwere ezigbo nguzogide mmiri ma na-anọgidesi ike na oke okpomọkụ. Ọ bụrụ na agbakwunyere plasticizers hygroscopic, elongation na mgbanwe nwere ike ime ka ọ dịkwuo mma, a pụkwara imeziwanye mgbanwe ahụ. Plasticizers dị ka glycerol na sorbitol bụ ndị kasị adabara. Nleba anya ngwọta n'ozuzu bụ 2% ~ 3%, na usoro ọgwụgwọ plasticizer bụ 10% ~ 20% nke cellulose ether. Ọ bụrụ na achọrọ ọdịnaya plasticizer ka ọ dị elu, colloid syneresis ga-eme n'okpuru oke iru mmiri. Ike ike nke ihe nkiri ahụ na plasticizer agbakwunyere dị ukwuu karịa nke ihe nkiri ahụ na-enweghị plasticizer, ọ na-abawanye na ọnụ ọgụgụ nke plasticizer agbakwunyere. Hygroscopicity nke ihe nkiri ahụ na-abawanye na ọnụ ọgụgụ nke plasticizer.


Oge nzipu: Feb-01-2024
Mkparịta ụka WhatsApp n'ịntanetị!