Hydroxypropyl methyl cellulose HPMC yog ib hom non-ionic cellulose tov ether, uas txawv ntawm ionic methyl carboxymethyl cellulose tov ether, thiab nws tsis hnov mob nrog hnyav hlau.Vim muaj qhov sib txawv ntawm cov ntsiab lus methoxyl thiab hydroxypropyl cov ntsiab lus hauv hydroxypropyl methylcellulose thiab cov viscosities sib txawv, nws tau dhau los ua ntau yam sib txawv nrog cov khoom sib txawv, piv txwv li, cov ntsiab lus methoxyl siab thiab cov ntsiab lus hydroxypropyl qis Nws qhov kev ua tau zoo yog ze rau ntawm methyl cellulose, thiab ntau yam nrog cov ntsiab lus methoxyl qis thiab cov ntsiab lus siab hydroxypropyl, nws qhov kev ua tau zoo yog ze rau ntawm hydroxypropyl methylcellulose.Txawm li cas los xij, nyob rau hauv ntau yam, txawm hais tias tsuas yog ib qho me me ntawm pawg hydroxypropyl lossis ib qho me me ntawm pawg methoxy muaj nyob, qhov solubility hauv cov kuab tshuaj organic lossis qhov kub ntawm flocculation hauv cov kua dej sib txawv heev.
1. Lub solubility ntawm hydroxypropyl methylcellulose
① Solubility ntawm hydroxypropyl methyl cellulose nyob rau hauv dej Hydroxypropyl methyl cellulose yog tiag tiag methyl cellulose hloov los ntawm propylene oxide (methyl oxypropylene), yog li nws tseem muaj cov khoom zoo ib yam li methyl cellulose.Cellulose zoo ib yam li dej txias solubility thiab dej kub insolubility.Txawm li cas los xij, vim yog hloov kho hydroxypropyl pawg, nws qhov kub thiab txias hauv dej kub yog siab dua li ntawm methyl cellulose.Piv txwv li, viscosity ntawm aqueous tov ntawm hydroxypropyl methylcellulose nrog 2% methoxyl cov ntsiab lus DS = 0.73 thiab hydroxypropyl cov ntsiab lus MS = 0.46 yog 500 mpa?s ntawm 20 ° C.Nws cov gel kub Nws tuaj yeem ncav cuag 100 ° C, thaum methylcellulose ntawm tib qhov kub tsuas yog li 55 ° C.Raws li rau nws solubility hauv dej, nws kuj tau zoo heev.Piv txwv li, pulverized hydroxypropyl methylcellulose (granular puab ntawm 0.2 ~ 0.5mm ntawm 20 ° C nrog ib tug viscosity ntawm 4% aqueous tov txog 2pa?s yuav siv tau nyob rau hauv chav tsev kub, nws yog yooj yim soluble nyob rau hauv dej tsis txias.
② Lub solubility ntawm hydroxypropyl methyl cellulose nyob rau hauv cov kuab tshuaj organic Lub solubility ntawm hydroxypropyl methyl cellulose nyob rau hauv cov kuab tshuaj organic kuj zoo dua li ntawm methyl cellulose, thiab methyl cellulose yuav tsum muaj ib tug degree ntawm methoxyl hloov nyob rau hauv cov khoom saum toj no 2.1, thiab high-viscosity hydroxypropyl methyl methyl viscosity. hydroxypropyl MS = 1.5 ~ 1.8 thiab methoxy DS = 0.2 ~ 1.0, thiab tag nrho cov kev hloov pauv qib siab tshaj 1.8 yog soluble hauv anhydrous methanol thiab ethanol daws nruab nrab, thermoplastic thiab dej-soluble.Nws kuj yog soluble hauv chlorinated hydrocarbons xws li dichloromethane thiab chloroform, thiab hauv cov kuab tshuaj organic xws li acetone, isopropanol thiab diacetone cawv.Nws solubility hauv cov kuab tshuaj organic zoo dua li dej-soluble.
2. Cov yam ntxwv cuam tshuam rau viscosity ntawm hydroxypropyl methylcellulose
Kev cuam tshuam ntawm hydroxypropyl methyl cellulose viscosity Tus qauv viscosity kev txiav txim siab ntawm hydroxypropyl methyl cellulose, zoo li lwm cov cellulose ethers, yog ua raws li 2% aqueous tov ntawm 20 ° C.Lub viscosity ntawm tib cov khoom nce nrog nce concentration.Rau cov khoom uas muaj qhov sib txawv molecular hnyav ntawm tib qhov concentration, cov khoom uas muaj qhov hnyav dua molecular muaj viscosity ntau dua.Nws txoj kev sib raug zoo nrog kub yog zoo ib yam li cov methyl cellulose.Thaum kub nce, viscosity pib txo, tab sis thaum nws nce mus txog qhov kub thiab txias, viscosity dheev nce thiab gelation tshwm sim.Lub gel kub ntawm cov khoom uas tsis muaj viscosity yog siab dua.yog siab.Nws cov ntsiab lus gel tsis yog tsuas yog cuam tshuam nrog viscosity ntawm ether, tab sis kuj rau qhov sib piv ntawm methoxy thiab hydroxypropyl hauv ether thiab tag nrho cov kev hloov pauv.Nws yuav tsum tau muab sau tseg tias hydroxypropyl methylcellulose kuj yog pseudoplastic thiab nws cov tshuaj yog ruaj khov nyob rau hauv chav tsev kub tsis muaj degradation ntawm viscosity tsuas yog muaj peev xwm ntawm enzymatic degradation.
3. Hydroxypropyl methylcellulose acid thiab alkali tsis kam
Hydroxypropyl methylcellulose acid thiab alkali tsis kam Hydroxypropyl methylcellulose feem ntau ruaj khov rau cov kua qaub thiab alkali, thiab tsis cuam tshuam rau thaj tsam ntawm pH 2 ~ 12.Nws tuaj yeem tiv taus qee yam ntawm lub teeb acid.Xws li formic acid, acetic acid, citric acid, succinic acid, phosphoric acid, boric acid, thiab lwm yam. Txawm li cas los xij, concentrated acid muaj cov nyhuv ntawm kev txo viscosity.Alkali xws li caustic soda, caustic potash thiab txiv qaub dej tsis muaj kev cuam tshuam rau nws, tab sis tuaj yeem ua rau me ntsis nce viscosity ntawm cov tshuaj, thiab tom qab ntawd yuav muaj qhov tshwm sim qeeb qeeb yav tom ntej.
4. Kev sib xyaw ntawm hydroxypropyl methylcellulose
Miscibility ntawm Hydroxypropyl Methyl Cellulose Hydroxypropyl methyl cellulose tov tuaj yeem tov nrog dej-soluble polymer compound kom dhau los ua cov tshuaj sib xws thiab pob tshab nrog ntau dua viscosity.Cov khoom siv polymer no suav nrog polyethylene glycol, polyvinyl acetate, polysiloxane, polymethyl vinyl siloxane, hydroxyethyl cellulose thiab methyl cellulose.Ntuj polymer tebchaw xws li cov pos hniav arabic, locust taum gum, karaya gum, thiab lwm yam kuj muaj zoo mixability nrog nws cov tshuaj.Hydroxypropyl methylcellulose tuaj yeem sib xyaw nrog mannitol lossis sorbitol esters ntawm stearic acid lossis palmitic acid, thiab tuaj yeem sib xyaw nrog glycerin, sorbitol thiab mannitol.Cov tshuaj no tuaj yeem siv ua hydroxypropyl methylcellulose.Cellulose-raws li plasticizer.
5. Insolubility thiab dej solubility ntawm hydroxypropyl methylcellulose
Cov dej tsis muaj dej-soluble cellulose ethers ntawm hydroxypropyl methylcellulose tuaj yeem ua qhov sib txuas nrog aldehydes, thiab cov dej-soluble ethers yog precipitated hauv cov tshuaj thiab ua insoluble hauv dej.Cov aldehydes uas ua rau hydroxypropyl methylcellulose insoluble muaj xws li formaldehyde, glyoxal, succinaldehyde, adipaldehyde, thiab lwm yam. Thaum siv formaldehyde, tshwj xeeb yuav tsum tau them rau pH tus nqi ntawm cov tshuaj, cov uas glyoxal reacts sai.Yog li ntawd, glyoxal feem ntau yog siv los ua tus neeg sawv cev crosslinking hauv kev tsim khoom.Qhov ntau npaum ntawm hom crosslinking tus neeg sawv cev hauv kev daws yog 0.2% ~ 10% ntawm ether pawg, nyiam dua 7% ~ 10%, thiab 3.3% ~ 6% yog qhov haum tshaj plaws rau glyoxal.Qhov kev kho mob dav dav yog 0 ~ 30 ℃, thiab lub sijhawm yog 1 ~ 120min.Cov tshuaj tiv thaiv kev sib txuas yuav tsum tau ua nyob rau hauv acidic tej yam kev mob.Feem ntau, inorganic muaj zog acid los yog organic carboxylic acid yog ntxiv rau cov tshuaj los kho cov pH ntawm cov tshuaj mus txog 2 ~ 6, nyiam dua ntawm 4 ~ 6, thiab tom qab ntawd aldehydes tau ntxiv los ua cov tshuaj tiv thaiv kev sib txuas..Cov kua qaub uas siv muaj xws li hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxyacetic acid, succinic acid los yog citric acid, ntawm cov formic acid los yog acetic acid yog haum, thiab formic acid yog qhov zoo tshaj plaws.Cov kua qaub thiab aldehyde kuj tuaj yeem ntxiv ib txhij kom tso cai rau kev daws teeb meem crosslink hauv qhov xav tau pH ntau.Cov tshuaj tiv thaiv no feem ntau yog siv rau hauv cov txheej txheem kho zaum kawg hauv kev npaj ntawm cellulose ethers.Tom qab cov cellulose ether yog insolubilized, nws yog qhov yooj yim los ntxuav thiab ntxuav nrog dej ntawm 20 ~ 25 ° C.Thaum cov khoom siv, cov tshuaj alkaline tuaj yeem muab ntxiv rau hauv cov tshuaj ntawm cov khoom los kho cov pH ntawm cov tshuaj kom alkaline, thiab cov khoom yuav yaj hauv cov tshuaj sai sai.Txoj kev no kuj tseem siv tau rau cov tshuaj cellulose ether ua rau hauv cov yeeb yaj kiab thiab tom qab ntawd cov yeeb yaj kiab tau ua tiav los ua rau nws ua ib zaj yeeb yaj kiab insoluble.
6. Hydroxypropyl methylcellulose tiv taus cov enzymes
Hydroxypropyl methylcellulose tiv taus cov enzymes.Nyob rau hauv txoj kev xav, cellulose derivatives, xws li txhua pawg anhydroglucose, muaj ib pab pawg neeg sib koom ua ke, uas tsis yooj yim rau kev kis kab mob, tab sis qhov tseeb cov khoom tiav thaum hloov pauv tus nqi ntau dua 1, nws tseem yuav degraded los ntawm enzymes, uas txhais tau hais tias qhov kev hloov pauv ntawm txhua pab pawg ntawm cov saw cellulose tsis zoo ib yam txaus, thiab cov kab mob tuaj yeem ua rau ze li ntawm cov pab pawg uas tsis tau hloov pauv los ua cov suab thaj., uas yog absorbed li as-ham rau microorganisms.Yog li ntawd, yog tias qhov kev hloov pauv ntawm etherification degree ntawm cellulose nce, qhov kev tiv thaiv rau enzymatic yaig ntawm cellulose ether kuj tseem txhim kho.Nws tau tshaj tawm tias cov residual viscosity ntawm hydroxypropyl methylcellulose (DS = 1.9) yog 13.2%, methylcellulose (DS = 1.83) yog 7.3%, thiab methylcellulose (DS = 1.66) yog 3.8%, thiab hydroxyethyl cellulose yog 1.7%.Nws tuaj yeem pom tias muaj peev xwm tiv thaiv enzyme ntawm hydroxypropyl methylcellulose muaj zog.Yog li ntawd, qhov zoo heev enzyme kuj ntawm hydroxypropyl methylcellulose, ua ke nrog nws zoo dispersibility, thickening thiab film-forming zog, feem ntau yog siv nyob rau hauv dej-emulsion txheej, thiab lwm yam., thiab feem ntau tsis tas yuav tsum tau ntxiv ntawm preservatives.Txawm li cas los xij, rau kev khaws cia ntev ntev ntawm kev daws teeb meem lossis qhov muaj peev xwm sib kis ntawm lub ntiaj teb sab nraud, cov tshuaj tua kab mob tuaj yeem raug ntxiv raws li kev ceev faj, thiab kev xaiv tuaj yeem txiav txim siab raws li qhov yuav tsum tau ua ntawm kev daws teeb meem.Phenylmercuric acetate thiab manganese fluorosilicate yog cov tshuaj tiv thaiv zoo, tab sis lawv muaj ob qho tib si Toxicity, kev saib xyuas yuav tsum tau them rau kev ua haujlwm, thiab qhov ntau npaum li cas yog 1 ~ 5mg ntawm phenylmercuric acetate ib liter ntawm kev daws.
7. Cov khoom ntawm hydroxypropyl methylcellulose zaj duab xis
Kev ua haujlwm ntawm hydroxypropyl methylcellulose zaj duab xis Hydroxypropyl methylcellulose muaj cov yeeb yaj kiab zoo heev, thiab nws cov kua dej los yog cov kuab tshuaj organic yog coated rau ntawm iav phaj, thiab nws yuav tsis muaj xim thiab pob tshab tom qab ziab.Thiab tawv tawv.Nws muaj cov dej noo zoo thiab tseem ruaj khov ntawm qhov kub thiab txias.Piv txwv li, ntxiv hygroscopic plasticizer tuaj yeem txhim kho nws qhov elongation thiab yoog raws.Txhawm rau txhim kho kev yooj yim, cov yas yas xws li glycerin thiab sorbitol yog qhov tsim nyog tshaj plaws.Qhov kev daws teeb meem dav dav yog 2% ~ 3%, thiab cov yas yas yog 10% ~ 20% ntawm cellulose ether.Yog hais tias cov ntsiab lus ntawm plasticizer siab dhau lawm, lub shrinkage tshwm sim ntawm colloid lub cev qhuav dej yuav tshwm sim nyob rau hauv high humidity.Lub zog tensile ntawm zaj duab xis nrog plasticizer ntxiv yog qhov loj dua qhov uas tsis muaj plasticizer, thiab nws nce nrog qhov nce ntawm cov nyiaj ntxiv.Raws li rau hygroscopicity ntawm zaj duab xis, nws kuj nce nrog qhov nce ntawm cov nyiaj plasticizer.
Post lub sij hawm: Oct-13-2022