Hydroxypropyl methyl cellulose HPMC yog ib qho uas tsis yog-ionic cellulose tov ether nyob rau hauv ntau yam thiab ionic methyl carboxymethyl cellulose tov ether, nws tsis hnov mob nrog hnyav hlau. Ib qho oxygen radicals vim yog hydroxypropyl methyl cellulose cov ntsiab lus thiab qhov sib txawv ntawm hydroxypropyl cov ntsiab lus thiab viscosity, tau los ua ntau yam ntawm kev ua tau zoo, piv txwv li, cov ntsiab lus methoxyl siab thiab cov ntsiab lus qis ntawm hydroxypropyl ntau yam, nws qhov kev ua tau zoo yog ze rau methyl cellulose thiab qis methoxyl. cov ntsiab lus thiab cov ntsiab lus siab ntawm hydroxypropyl ntau yam, thiab nws qhov kev ua tau zoo yog ze rau hydroxypropyl methyl cellulose yog tsim. Tab sis nyob rau hauv txhua yam, txawm hais tias tsuas muaj ib tug me me ntawm hydroxypropyl los yog ib tug me me npaum li cas ntawm methoxy, solubility nyob rau hauv organic solvents los yog flocculation kub nyob rau hauv aqueous tov, muaj ib tug zoo sib txawv.
1, hydroxypropyl methyl cellulose solubility
Hydroxypropyl methyl cellulose nyob rau hauv dej solubility ntawm hydroxypropyl methyl cellulose yog tiag tiag ib hom propylene oxide (methyl oxypropyl nplhaib) hloov methyl cellulose, yog li nws tseem muaj xws li methyl cellulose txias dej soluble thiab dej kub insoluble yam ntxwv. Txawm li cas los xij, gelation kub ntawm hloov hydroxy propyl yog ntau dua li ntawm methyl cellulose hauv dej kub. Piv txwv li, viscosity ntawm hydroxypropyl methylcellulose aqueous tov nrog 2% methoxy cov ntsiab lus DS = 0.73 thiab hydroxypropyl cov ntsiab lus MS = 0.46 yog 500 mpa ntawm 20 ℃. Lub gel kub ntawm S cov khoom yog ze rau 100 ℃, thaum lub methyl cellulose ntawm tib qhov kub tsuas yog hais txog 55 ℃. Raws li rau nws solubility nyob rau hauv dej, kuj zoo heev txhim kho, piv txwv li, tom qab crushed hydroxypropyl methylcellulose (grain puab 0.2 ~ 0.5 hli ntawm 20 ℃ 4% aqueous viscosity ntawm 2pA? S khoom yuav yooj yim yaj nyob rau hauv dej tsis txias ntawm chav tsev kub. .
(2) Hydroxypropyl methyl cellulose nyob rau hauv cov organic solvents solubility ntawm hydroxypropyl methyl cellulose nyob rau hauv cov organic solvents solubility, kuj zoo dua methyl cellulose, methyl cellulose xav tau nyob rau hauv lub methoxy hloov qib ntawm 2.1 los yog ntau tshaj cov khoom, thiab muaj hydroxypropyl MS = 1.5 ~ 1.8 thiab methoxy DS = 0.2 ~ 1.0, Siab viscosity hydroxypropyl methyl cellulose nrog tag nrho cov kev hloov pauv qib siab tshaj 1.8 yog soluble hauv anhydrous methanol thiab ethanol daws, thiab muaj thermoplastic thiab dej solubility. Nws kuj yog soluble hauv chlorinated hydrocarbons xws li dichloromethane thiab trichloromethane, thiab cov organic solvents xws li acetone, isopropyl cawv, thiab diacetone cawv. Nws solubility nyob rau hauv cov kuab tshuaj organic yog superior rau dej solubility.
2, hydroxypropyl methyl cellulose viscosity ntawm cov yam ntxwv cuam tshuam
Hydroxypropyl methylcellulose viscosity yam tseem ceeb hydroxypropyl methylcellulose tus qauv viscosity kev txiav txim, thiab lwm yam cellulose ether yog tib yam, nyob ntawm 20 ℃ nrog 2% aqueous tov raws li tus qauv kev txiav txim. Lub viscosity ntawm tib yam khoom, nrog rau kev nce ntawm concentration thiab nce, tib lub concentration ntawm txawv molecular hnyav khoom, molecular hnyav ntawm cov khoom yog siab viscosity. Nws txoj kev sib raug zoo nrog kub yog zoo ib yam li cov methyl cellulose. Thaum kub nce, viscosity pib poob, tab sis thaum nws nce mus txog qhov kub thiab txias, qhov viscosity dheev nce thiab gelation tshwm sim. Lub gelation kub ntawm cov khoom uas tsis muaj viscosity yog siab dua li cov khoom uas muaj viscosity siab. Cov theem ntawm nws cov ntsiab lus gel, ntxiv rau qhov siab thiab qis viscosity ntawm ether, tab sis kuj nrog ether methoxy thiab hydroxypropyl pawg muaj pes tsawg leeg thiab tag nrho cov kev hloov pauv muaj feem cuam tshuam. Nws yuav tsum raug sau tseg tias hydroxypropyl methylcellulose kuj yog pseudoplastic; nws cov kev daws teeb meem yog ruaj khov thaum khaws cia hauv chav tsev kub thiab tsis pom kev degradation ntawm viscosity tsuas yog muaj peev xwm ntawm enzymatic degradation.
3, hydroxypropyl methyl cellulose acid thiab alkaline tsis kam
Hydroxypropyl methylcellulose acid alkali hydroxypropyl methylcellulose acid thiab alkali, feem ntau yog ruaj khov, nyob rau hauv ph PH2 ~ 12 ntau yam tsis cuam tshuam, nws muaj peev xwm tiv taus ib tug npaum li cas ntawm lub teeb acid, xws li formic acid, acetic acid, citric acid, succinic acid, phosphoric. acid, boric acid, thiab lwm yam. Tab sis cov concentrated acid muaj cov nyhuv ntawm kev txo cov viscosity. Alkali xws li caustic soda, caustic potassium thiab txiv qaub dej tsis muaj kev cuam tshuam rau nws, tab sis cov nyhuv ntawm me ntsis nce viscosity ntawm cov tshuaj yuav txo qis rau yav tom ntej.
4, hydroxypropyl methyl cellulose tuaj yeem sib xyaw
Hydroxypropyl methyl cellulose tov tuaj yeem tov nrog dej-soluble polymer tebchaw, thiab dhau los ua cov kua dej tsis sib xws nrog cov viscosity siab dua. Cov ntsiab lus siab molecular no yog polyethylene glycol, polyvinyl acetate, polysilicone, polymethyl vinyl siloxane thiab hydroxyethyl cellulose thiab methyl cellulose, thiab lwm yam. Natural polymer tebchaw xws li cov pos hniav Arabic, locust taum gum, pos ntoo pos thiab lwm yam kuj muaj ib tug zoo sib tov nrog nws. daws. Hydroxypropyl methyl cellulose kuj tuaj yeem tov nrog stearic acid lossis palmitic acid mannitol ester lossis sorbitol ester, tab sis kuj nrog glycerol, sorbitol thiab mannitol, cov tshuaj no tuaj yeem siv los ua hydroxypropyl methyl cellulose plasticizer.
5, hydroxypropyl methyl cellulose insoluble dej soluble
Hydroxypropyl methyl cellulose insoluble dej-soluble cellulose ether, tuaj yeem ua qhov sib txuas nrog aldehydes, thiab ua rau cov dej-soluble ether precipitated hauv cov tshuaj, ua insoluble hauv dej. Thiab ua rau hydroxypropyl methylcellulose insoluble aldehyde, formaldehyde, glyoxal, succinaldehyde, dialdehyde, thiab lwm yam., kev siv formaldehyde yuav tsum tau them tshwj xeeb mloog mus rau PH nqi ntawm cov tshuaj, nyob rau hauv uas glyoxal cov tshuaj tiv thaiv sai, yog li nyob rau hauv industrial ntau lawm feem ntau siv glyoxal raws li tus ntoo khaub lig. - txuas tus neeg sawv cev. Qhov ntau npaum li cas ntawm tus neeg sawv cev crosslinking hauv kev daws yog 0.2% ~ 10% ntawm ether pawg, qhov zoo tshaj plaws yog 7% ~ 10%, xws li kev siv glyoxal nrog 3.3% ~ 6% yog qhov tsim nyog tshaj plaws. Qhov kev kho mob dav dav yog 0 ~ 30 ℃, 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 ces aldehydes ntxiv rau kev sib txuas cov tshuaj tiv thaiv. Cov kua qaub uas siv yog hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxy acetic acid, succinic acid los yog citric acid, ntawm cov formic acid los yog acetic acid yog qhov zoo tshaj plaws, thaum formic acid yog qhov zoo tshaj plaws. Cov kua qaub thiab aldehydes kuj tseem tuaj yeem ntxiv rau tib lub sijhawm kom tso cai rau kev daws teeb meem sib txuas hauv qhov xav tau PH ntau. Cov tshuaj tiv thaiv no feem ntau yog siv rau hauv cov txheej txheem kawg ntawm kev npaj cellulose ether, kom cellulose ether tsis yaj, yooj yim siv 20 ~ 25 ℃ dej los ntxuav thiab purify. Thaum siv 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 tau yaj sai sai hauv cov tshuaj. Txoj kev no tseem tuaj yeem siv tau thaum cov tshuaj cellulose ether siv los ua cov yeeb yaj kiab thiab tom qab ntawd cov yeeb yaj kiab raug kho los ua cov yeeb yaj kiab tsis zoo.
6, hydroxypropyl methyl cellulose anti-enzyme
Hydroxypropyl methyl cellulose enzyme tsis kam ntawm cellulose derivatives nyob rau hauv txoj kev xav, xws li txhua pawg anhydroglucose xws li muaj kev sib xyaw ua ke ntawm cov pab pawg hloov, kev yaig ntawm cov kab mob tsis tshua muaj kab mob, tab sis qhov tseeb cov khoom tiav los hloov cov nqi ntau dua 1, kuj los ntawm enzyme degradation, qhov no yog cov lus piav qhia ntawm txhua pab pawg nyob rau hauv lub cellulose saw hloov degree tsis sib xws, Microorganisms tuaj yeem erode. nyob ze unsubstituted dehydrated glucose pawg los tsim cov suab thaj, uas tuaj yeem nqus tau los ntawm cov kab mob ua zaub mov. Yog li, yog tias qhov kev hloov pauv ntawm etherification degree ntawm cellulose nce, qhov kev tiv thaiv ntawm cellulose ether rau enzymatic yaig yuav txhim kho. Nws tau tshaj tawm tias nyob rau hauv kev tswj hwm, qhov seem viscosity ntawm hydroxypropyl methyl cellulose (DS = 1.9), methyl cellulose (DS = 1.83), methyl cellulose (DS = 1.66), thiab hydroxyethyl cellulose (1.7%) yog 13.2%, 7.3%. , 3.8%, thiab 1.7%, feem. Hydroxypropyl methyl cellulose muaj zog tiv thaiv enzyme muaj peev xwm. Yog li hydroxypropyl methylcellulose zoo heev los tiv thaiv enzyme, ua ke nrog nws zoo dispersion, thickening thiab zaj duab xis tsim, thov nyob rau hauv emulsion txheej, thiab lwm yam., feem ntau tsis tas yuav ntxiv preservatives. Txawm li cas los xij, txhawm rau tiv thaiv kev khaws cia ntev ntev ntawm kev daws teeb meem lossis tuaj yeem kis tau los ntawm lub ntiaj teb sab nraud, cov tshuaj tua kab mob tuaj yeem ntxiv, uas nws xaiv tuaj yeem txiav txim siab raws li qhov yuav tsum tau ua ntawm kev daws teeb meem. Phenylmercuric acetate thiab manganese fluosilicate yog cov tshuaj tiv thaiv zoo, tab sis lawv yog cov tshuaj lom thiab yuav tsum tau ua tib zoo ua haujlwm. Feem ntau, 1 ~ 5mg phenylmercuric acetate tuaj yeem muab ntxiv rau txhua liter ntawm kev daws.
7, hydroxypropyl methyl cellulose membrane kev ua tau zoo
Hydroxypropyl methyl cellulose zaj duab xis kev ua tau zoo ntawm hydroxypropyl methyl cellulose muaj zaj duab xis zoo heev, nws cov tshuaj aqueous los yog cov kuab tshuaj organic, coated rau ntawm iav phaj, tom qab ziab yuav tsis muaj xim, pob tshab thiab tawv zaj duab xis. Nws muaj cov dej noo zoo thiab tseem ruaj khov ntawm qhov kub thiab txias. Xws li qhov sib ntxiv ntawm hygroscopic plasticizer, tuaj yeem txhim kho nws cov elongation thiab yooj, txhim kho flexure, glycerol thiab sorbitol thiab lwm yam plasticizer yog qhov tsim nyog tshaj. Qhov kev daws teeb meem dav dav yog 2% ~ 3%, cov tshuaj yas yas yog 10% ~ 20% ntawm cellulose ether. Yog hais tias cov ntsiab lus ntawm plasticizer yog exigent, 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 ntxiv plasticizer yog loj dua qhov uas tsis tau ntxiv, thiab nce nrog qhov nce ntawm cov nyiaj ntxiv, raws li hygroscopicity ntawm cov yeeb yaj kiab kuj tseem nce ntxiv nrog qhov nce ntawm cov nyiaj plasticizer.
Post lub sij hawm: Sep-08-2022