Focus on Cellulose ethers

Hydroxypropyl methylcellulose HPMC?

Hydroxypropyl methylcellulose HPMC o se non-ionic cellulose fefiloi ether i totonu o ether fefiloi eseese ma ionic methylcarboxymethylcellulose. E le tali atu i u'amea mamafa. O le eseesega i le anotusi o le hydroxypropyl methylcellulose, hydroxypropyl methylcellulose, ma le hydroxypropyl content ratio ma le viscosity o le gene free okesene e matua eseese lava ituaiga i tulaga o le faatinoga. Mo se faʻataʻitaʻiga, o ituaiga e maua ai le maualuga o le methoxyl content ma le maualalo o le hydroxypropyl content e eseese faʻatinoga. E latalata ile methylcellulose ma le maualalo o le methoxy i totonu o ituaiga. Pe a faatusatusa i ituaiga e maualuga atu le hydroxypropyl content, o lona faatinoga e latalata i le hydroxypropyl methylcellulose na gaosia. Ae ui i lea, e ui lava o ituaiga taʻitasi e aofia ai naʻo se vaega itiiti o le hydroxypropyl group poʻo se vaega itiiti o le methoxy group, e tele eseesega i le solubility i solvents organic poʻo le vevela o le flocculation i vaifofo vai.

 

1. Solubility o le hydroxypropyl methylcellulose

Solubility o le hydroxypropyl methylcellulose i totonu o le vai Hydroxypropyl methylcellulose o le mea moni o se propylene oxide (methylhydroxypropyl mama) suia methylcellulose, o lea o loʻo i ai pea uiga tutusa e pei o le methylcellulose E tutusa uiga o le soluble i le vai malulu ae le mafai ona faʻafefe i le vai vevela. Ae ui i lea, o le vevela gelling o suiga hydroxypropyl i le vai vevela e sili atu le maualuga nai lo le methylcellulose. Mo se faʻataʻitaʻiga, o le 2% hydroxypropyl methylcellulose solution vai ma le methoxy group content DS=0.73 ma le hydroxypropyl group content MS=0.46 ei ai le viscosity o le 500mpa i le 20°C. Ole vevela ole gel ole oloa S e latalata ile 100°C, ae ole methylcellulose ile vevela tutusa e na'o le 55°C. Ae mo lona soluble i le vai, ua matua faaleleia foi. Mo se faʻataʻitaʻiga, a maeʻa ona nutimomoia le hydroxypropyl methylcellulose (o le foliga o le 0.2 ~ 0.5mm, o le viscosity o le 4% vai i le 20 ° C o le 2pA · S, e mafai ona faʻaaogaina i le vevela o le potu e aunoa ma le malulu. Faʻafaigofie ona faʻafefe i le vai).

 

(2) O le solubility o le hydroxypropyl methylcellulose i totonu o vailaʻau faʻale-aganuʻu O le solubility o le hydroxypropyl methylcellulose i totonu o vailaʻau faʻasolosolo e sili atu foi nai lo le methylcellulose. Methylcellulose e manaʻomia se tikeri suitulaga methoxy o 2.1 O oloa o loʻo i luga o loʻo i ai le maualuga o le viscosity hydroxypropyl methylcellulose ma le hydroxypropyl MS = 1.5 ~ 1.8 ma le methoxy DS = 0.2 ~ 1.0, faʻatasi ai ma le aofaʻi atoa o le sui o le sili atu i le 1.8, ma e faigofie ona solu i le methanol anhydrous. vaifofo ethanol. Thermoplastic ma solu vai. E mafai foi ona solu i le chlorinated hydrocarbons e pei o le methylene chloride ma le chloroform, ma solvents organic pei ole acetone, isopropyl alcohol ma le diacetone alcohol. O lona solubility i soluble organic e sili atu nai lo le solubility i le vai.

 

2. O mea e aafia ai le viscosity o le hydroxypropyl methylcellulose

Hydroxypropyl methylcellulose viscosity factor O le fua masani o le viscosity o le hydroxypropyl methylcellulose e tutusa ma isi cellulose ethers, ma e fuaina i le 20 ° C ma le 2% vaifofo vai e pei o le tulaga masani. O le viscosity o le oloa lava e tasi e faʻateleina pe a faʻateleina le faʻaogaina. Mo oloa e tutusa le faʻatonuga ma eseese mole mole mamafa, o le oloa e tele mole mamafa mamafa e maualuga atu le viscosity. O lona sootaga ma le vevela e tutusa ma le methylcellulose. A oʻo i luga le vevela, e amata ona faʻaitiitia le viscosity, ae a oʻo i se vevela, faʻafuaseʻi ona oso aʻe le viscosity ma tupu ai le gelation. O oloa viscosity maualalo e maualuga atu le vevela gelling nai lo oloa viscosity maualuga. O le gel point e le gata e fesoʻotaʻi ma le viscosity o le ether, ae e fesoʻotaʻi foi ma le fua faatatau o le methoxy ma le hydroxypropyl vaega i le ether ma le tikeri atoa o le sui. E tatau ona maitauina o le hydroxypropyl methylcellulose o le pseudoplastic foi; e mautu ona fofo pe a teuina i le vevela o le potu ma e le faʻaalia se faʻaitiitia o le viscosity, sei vagana ai le faʻaleagaina o le enzymatic.

 

3. Hydroxypropyl methylcellulose o le acid ma alkali tetee

Hydroxypropyl methylcellulose e fa'asa'o ma le alkali. Hydroxypropyl methyl cellulose o le acid ma alkali tetee. E masani ona mautu ma o le a le afaina i le tau pH i le va o PH2 ~ 12. E mafai ona tatalia se aofaiga o mea vaivai vaivai, e pei o le formic acid, acetic acid, ma le tipolo. Acid, succinic acid, phosphoric acid ae concentrated acid ei ai le aafiaga o le faʻaitiitia o le viscosity. Ole alkali e pei ole sua suamalie, potassium masima, ma vai lime e leai sona aoga, ae ole a'afiaga ole fa'atuputeleina o le viscosity ole vaifofo o le a faasolosolo malie lava ona fa'aitiitia mulimuli ane.

 

4. Hydroxypropyl methylcellulose e mafai ona faʻafefiloi

Hydroxypropyl methylcellulose solution e mafai ona fa'afefiloi ma vai-soluble polymer compounds e fausia ai se toniga ma manino fofo ma maualuga viscosity. O nei polymer compound e aofia ai polyethylene glycol, polyvinyl acetate, polysiloxane, polymethyl vinyl siloxane, hydroxyethyl cellulose ma methyl cellulose. O mea fa'apolopolo fa'alenatura e pei o le acacia gum, locust bean gum, locust gum, etc. e lelei fo'i le fefiloi. lona fofo. Hydroxypropyl methylcellulose e mafai foi ona faʻafefiloi ma le stearic acid poʻo le mannitol palmitate poʻo le sorbitol, ma e mafai foi ona faʻafefiloi ma le glycerin, sorbitol ma le mannitol. E mafai ona fa'aogaina nei mea fa'apipi'i e fai ma sui fa'apipi'i hydroxypropyl methylcellulose.

 

5. Hydroxypropyl methylcellulose e le mafai ona solu i le vai

Hydroxypropyl methylcellulose e le mafai ona solu i vai-soluble cellulose ethers ma e mafai ona feso'ota'i i luga o le eleele ma aldehydes, ma mafua ai ona fa'afefeteina nei ethers solu vai i le vaifofo ma e le mafai ona solu i le vai. Ma faia le hydroxypropyl methylcellulose insoluble i aldehydes, formaldehyde, glyoxal, succinic acid, dialdehyde, ma isi. Pe a faʻaaogaina formaldehyde, e tatau ona totogi faʻapitoa i le tau pH o le fofo. Faatasi ai ma i latou, glyoxal tali vave, o lea e faʻaaogaina i alamanuia Glyoxal e masani ona faʻaaogaina e fai ma sui faʻafesoʻotaʻi i le gaosiga. -Sui feso'ota'iga. O le fua o lenei ituaiga o fesoʻotaʻiga soʻotaga i totonu o le vaifofo o le 0.2% i le 10% o le mamafa o le eter, ma o le mea sili o le 7% i le 10%. Afai e faʻaaogaina le glyoxal, 3.3% i le 6% e sili ona talafeagai. Ole vevela ole togafitiga lautele ole 0 ~ 30℃ ma le taimi ole 1 ~ 120min. E mana'omia ona faia le fa'agasologa o feso'ota'iga i lalo ole tulaga fa'ama'i. E masani lava, e fa'aopoopo i le vaifofo le pH o le vaifofo pe tusa o le 2 i le 6, sili i le va o le 4 ma le 6, ona fa'aopoopo lea o aldehydes e fa'atino ai le fa'afeso'ota'i. O vailaʻau o loʻo faʻaaogaina e aofia ai le hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, glycolic acid, succinic acid poʻo le citric acid, e aofia ai le formic acid poʻo le acetic acid e sili ona lelei, ma le formic acid e sili ona lelei. O acids ma aldehydes e mafai fo'i ona fa'aopoopo i le taimi e tasi e fa'afeso'ota'i ai le vaifofo i totonu o le pH e mana'omia. O lenei tali e masani ona faʻaaogaina i le laasaga mulimuli o le gaosiga o le cellulose ether e faʻafefe ai le cellulose ether ma faʻafaigofie le fufuluina ma le faʻamamaina i le 20 ~ 25 ° C vai. Pe a faʻaaogaina le oloa, e mafai ona e faʻaopopo mea alkaline i le fofo o oloa e fetuunai ai le pH o le vaifofo e avea ma alkaline ina ia vave faʻamavae le oloa i le fofo. O lenei metotia e mafai foi ona faʻaoga pe a saunia se ata e faʻaaoga ai le cellulose ether solution ona faʻapipiʻiina lea o le ata i se ata e le mafai ona faʻaaogaina.

 

6. Hydroxypropyl methylcellulose anti-enzyme

O mea e maua mai i le cellulose o le hydroxypropyl methylcellulose o loʻo teteʻe faʻapitoa i enzymes. Mo se fa'ata'ita'iga, o kulupu anhydroglucose ta'itasi o lo'o fa'amaumau fa'atasi ma se vaega e suitulaga ma e le a'afia i le tafia ma fa'ama'i pipisi. Ae ui i lea, o le mea moni, o le tau suia o le oloa maeʻa e sili atu i le 1. E mafai foi ona faʻaleagaina e enzymes, lea e faʻaalia ai o le tikeri o le suitulaga o vaega taʻitasi i le filifili cellulose e le tutusa, ma e mafai e microorganisms ona faʻaumatia vaega lata ane e le suitulaga anhydroglucose e fausia. suka, lea e mafai ona mitiia e microorganisms e fai ma meaai. O le mea lea, afai o le tikeri o le ether suitulaga o cellulose faateleina, o le a faateleina le tetee o cellulose ethers i osofaiga enzymatic. Ua lipotia mai i lalo o tulaga pulea, hydroxypropyl methylcellulose (DS = 1.9), methylcellulose (DS = 1.83), methylcellulose (DS = 1.66), hydroxyethylcellulose (1.7%) O viscosities totoe o 13.2%, 7.3%, 3.8% ma 1.7% taitasi. O le Hydroxypropyl methylcellulose o loʻo i ai le malosi o le anti-enzyme. E mafai ona iloa o le hydroxypropyl methylcellulose e sili atu le tetee o le enzyme, faʻatasi ai ma lona faʻasalalau lelei, mafiafia ma mea e fai ata tifaga, e mafai ona faʻaaogaina i le emulsion coatings, ma isi, ma e masani lava e le manaʻomia le faʻaopoopoga o mea faʻasao. Ae ui i lea, ina ia puipuia le vaifofo mai le teuina mo se taimi umi poʻo le faʻaleagaina i fafo, e mafai ona faʻaopoopo mea faʻasao, ma e mafai ona fuafua le filifiliga o mea faʻasao e faʻatatau i manaʻoga mulimuli o le fofo. Phenylmercuric acetate ma manganese fluorosilicate o ni puipuiga lelei, ae e oona ma e tatau ona taulimaina ma le faaeteete. E masani lava, 1 i le 5 mg o le phenylmercuric acetate e mafai ona faʻaopopo i lita taʻitasi o vaifofo.

 

7. Faʻatinoga o le membrane hydroxypropyl methylcellulose

Hydroxypropyl methylcellulose mea e fai ata tifaga O le Hydroxypropyl methylcellulose e sili ona lelei le faia o ata. Pe a faʻapipiʻiina lona vaifofo vai poʻo se vaifofo solvent organic i luga o se ipu tioata, e avea ma ata e leai se lanu, manino ma faigata pe a uma ona faʻagogo. . E lelei le susū e tete'e ma tumau mausali i le vevela maualuga. Afai e faʻapipiʻi hygroscopic plasticizers, e mafai ona faʻaleleia le faʻalauteleina ma le fetuutuunai, ma e mafai ona faʻaleleia le fetuutuunai. O mea fa'apipi'i pei ole glycerol ma le sorbitol e sili ona talafeagai. O le faʻatonuga lautele o le fofo o le 2% ~ 3%, ma o le vailaʻau plasticizer o le 10% ~ 20% o le cellulose ether. Afai e mana'omia le maualuga o mea fa'apipi'i, o le colloid syneresis o le a tupu i lalo ole susū maualuga. O le malosi faʻamalosi o le ata faʻatasi ma le plasticizer faaopoopo e sili atu nai lo le ata e aunoa ma le plasticizer, ma e faʻateleina i le aofaʻi o le plasticizer faaopoopo. O le hygroscopicity o le ata e faʻateleina foi i le aofaʻi o le plasticizer.


Taimi meli: Feb-01-2024
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