Hydroxypropyl methylcellulose HPMC yog ib qho uas tsis yog-ionic cellulose tov ether ntawm ntau yam sib xyaw ethers nrog ionic methylcarboxymethylcellulose. Nws tsis hnov mob nrog cov hlau hnyav. Qhov sib txawv ntawm cov ntsiab lus ntawm hydroxypropyl methylcellulose, hydroxypropyl methylcellulose, thiab hydroxypropyl cov ntsiab lus piv thiab viscosity ntawm cov noob tsis muaj oxygen muaj ntau yam sib txawv ntawm kev ua haujlwm. Piv txwv li, ntau yam uas muaj cov ntsiab lus methoxyl siab thiab cov ntsiab lus hydroxypropyl tsawg muaj qhov sib txawv. Ze rau methylcellulose thiab tsawg methoxy cov ntsiab lus ntau yam. Piv nrog rau ntau yam nrog cov ntsiab lus hydroxypropyl ntau dua, nws qhov kev ua tau zoo yog ze rau ntawm hydroxypropyl methylcellulose uas tsim. Txawm li cas los xij, txawm hais tias txhua yam muaj tsuas yog ib qho me me ntawm pawg hydroxypropyl lossis ib qho me me ntawm pawg methoxy, muaj qhov sib txawv loj hauv solubility hauv cov kuab tshuaj organic lossis flocculation kub hauv cov tshuaj aqueous.
1. Solubility ntawm hydroxypropyl methylcellulose
Solubility ntawm hydroxypropyl methylcellulose nyob rau hauv dej Hydroxypropyl methylcellulose yog tiag tiag propylene oxide (methylhydroxypropyl nplhaib) hloov methylcellulose, yog li nws tseem muaj cov khoom zoo ib yam li methylcellulose Nws muaj cov khoom zoo sib xws ntawm soluble hauv dej txias tab sis insoluble hauv dej kub. Txawm li cas los xij, qhov kub ntawm qhov hloov pauv hydroxypropyl hauv dej kub yog siab dua li ntawm methylcellulose. Piv txwv li, 2% hydroxypropyl methylcellulose aqueous tov nrog methoxy pawg ntsiab lus DS = 0.73 thiab hydroxypropyl pawg ntsiab lus MS = 0.46 muaj viscosity ntawm 500mpa ntawm 20 ° C. Lub gel kub ntawm S khoom yog ze rau 100 ° C, thaum lub 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, tom qab hydroxypropyl methylcellulose yog crushed (particle zoo yog 0.2 ~ 0.5 hli, viscosity ntawm 4% dej ntawm 20 ° C yog 2pA·S, nws tuaj yeem siv rau hauv chav tsev kub tsis txias. Yooj yim yaj hauv dej).
(2) Lub solubility ntawm hydroxypropyl methylcellulose nyob rau hauv cov kuab tshuaj organic Lub solubility ntawm hydroxypropyl methylcellulose nyob rau hauv cov kuab tshuaj organic kuj zoo dua li ntawm methylcellulose. Methylcellulose yuav tsum muaj methoxy hloov qib ntawm 2.1 Cov khoom saum toj no muaj cov viscosity hydroxypropyl methylcellulose nrog hydroxypropyl MS = 1.5 ~ 1.8 thiab methoxy DS = 0.2 ~ 1.0, nrog rau tag nrho cov kev hloov pauv ntau dua 1.8, thiab yooj yim soluble hauv anhydrous methanol thiab ethanol daws. Thermoplastic thiab dej-soluble. Nws kuj yog soluble hauv chlorinated hydrocarbons xws li methylene chloride thiab chloroform, thiab cov organic solvents xws li acetone, isopropyl cawv thiab diacetone cawv. Nws solubility hauv cov kuab tshuaj organic zoo dua li dej solubility.
2. Cov yam ntxwv cuam tshuam rau viscosity ntawm hydroxypropyl methylcellulose
Hydroxypropyl methylcellulose viscosity factor Tus qauv ntsuas viscosity ntawm hydroxypropyl methylcellulose yog tib yam li lwm cov cellulose ethers, thiab ntsuas ntawm 20 ° C nrog 2% aqueous tov raws li tus qauv. Lub viscosity ntawm tib yam khoom nce raws li qhov concentration nce. Rau cov khoom uas muaj tib lub concentration thiab sib txawv molecular luj, cov khoom uas muaj ib tug loj molecular hnyav muaj ib tug ntau viscosity. Nws txoj kev sib raug zoo nrog kub yog zoo ib yam li cov methylcellulose. Thaum kub nce, viscosity pib txo, tab sis thaum nws nce mus txog qhov kub thiab txias, qhov viscosity dheev nce thiab gelation tshwm sim. Cov khoom uas muaj viscosity tsawg muaj qhov kub thiab txias dua li cov khoom viscosity siab. Lub gel taw tes tsis yog tsuas yog cuam tshuam nrog viscosity ntawm ether, tab sis kuj muaj feem xyuam rau qhov sib piv ntawm methoxy thiab hydroxypropyl pawg hauv ether thiab tag nrho cov kev hloov pauv. 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 muaj qhov viscosity txo qis, tshwj tsis yog muaj peev xwm degradation enzymatic.
3. Hydroxypropyl methylcellulose yog acid thiab alkali resistant
Hydroxypropyl methylcellulose yog acid thiab alkali resistant. Hydroxypropyl methyl cellulose yog acid thiab alkali resistant. Nws feem ntau ruaj khov thiab yuav tsis cuam tshuam los ntawm tus nqi pH hauv thaj tsam ntawm PH2 ~ 12. Nws tuaj yeem tiv taus qee qhov tsis muaj zog acids, xws li formic acid, acetic acid, thiab txiv qaub. Acid, succinic acid, phosphoric acid tab sis concentrated acid muaj cov nyhuv ntawm 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 maj mam txo tom qab.
4. Hydroxypropyl methylcellulose tuaj yeem sib xyaw
Hydroxypropyl methylcellulose tov tuaj yeem tov nrog dej-soluble polymer tebchaw los tsim ib qho kev daws teeb meem thiab pob tshab nrog viscosity siab dua. 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 acacia gum, locust taum pos hniav, locust gum, thiab lwm yam kuj muaj zoo mixability. nws daws. Hydroxypropyl methylcellulose tuaj yeem sib xyaw nrog stearic acid lossis mannitol palmitate lossis sorbitol, thiab tuaj yeem tov nrog glycerin, sorbitol thiab mannitol. Cov tshuaj no tuaj yeem siv los ua hydroxypropyl methylcellulose plasticizers tus neeg sawv cev.
5. Hydroxypropyl methylcellulose yog insoluble hauv dej
Hydroxypropyl methylcellulose yog insoluble nyob rau hauv dej-soluble cellulose ethers thiab tuaj yeem nto-cross-txuas nrog aldehydes, ua rau cov dej-soluble ethers los nag hauv cov tshuaj thiab ua insoluble hauv dej. Thiab ua kom hydroxypropyl methylcellulose insoluble hauv aldehydes, formaldehyde, glyoxal, succinic acid, dialdehyde, thiab lwm yam. Thaum siv formaldehyde, tshwj xeeb yuav tsum tau them rau pH tus nqi ntawm cov tshuaj. Ntawm lawv, glyoxal reacts sai, yog li nws yog siv hauv kev lag luam Glyoxal feem ntau yog siv los ua tus neeg sawv cev sib txuas hauv kev tsim khoom. -Crosslinking tus neeg saib xyuas. Qhov ntau npaum li cas ntawm no hom cross-linking tus neeg sawv cev hauv cov tshuaj yog 0.2% mus rau 10% ntawm cov huab hwm coj ntawm ether, thiab qhov zoo tshaj plaws yog 7% mus rau 10%. Yog tias siv glyoxal, 3.3% mus rau 6% yog qhov tsim nyog tshaj. 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 txog 6, nyiam dua ntawm 4 thiab 6, thiab tom qab ntawd aldehydes tau ntxiv los ua cov tshuaj tiv thaiv kev sib txuas. Cov kua qaub siv xws li hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, glycolic acid, succinic acid los yog citric acid, ntawm cov formic acid los yog acetic acid yog qhov zoo tshaj plaws, thiab formic acid yog qhov zoo tshaj plaws. Cov kua qaub thiab aldehydes kuj tuaj yeem ntxiv ib txhij rau kev sib txuas cov tshuaj hauv qhov xav tau pH ntau. Cov tshuaj tiv thaiv no feem ntau yog siv rau hauv cov kauj ruam kawg ntawm kev npaj cellulose ether kom cov cellulose ether insoluble thiab pab ntxuav thiab purification nrog 20 ~ 25 ° C dej. Thaum siv cov khoom, koj tuaj yeem ntxiv cov tshuaj alkaline rau cov khoom siv los kho cov pH ntawm cov tshuaj kom alkaline kom cov khoom tuaj yeem yaj sai sai hauv cov tshuaj. Txoj kev no tseem tuaj yeem siv tau thaum cov yeeb yaj kiab tau npaj siv cov tshuaj cellulose ether thiab tom qab ntawd cov yeeb yaj kiab tau ua tiav rau hauv cov yeeb yaj kiab insoluble.
6. Hydroxypropyl methylcellulose anti-enzyme
Cov cellulose derivatives ntawm hydroxypropyl methylcellulose yog theoretically resistant rau enzymes. Piv txwv li, txhua pab pawg anhydroglucose tau ruaj khov nrog cov pab pawg hloov pauv thiab tsis cuam tshuam rau microbial yaig thiab kab mob. Txawm li cas los xij, qhov tseeb, qhov hloov pauv tus nqi ntawm cov khoom tiav lawm ntau tshaj 1. Nws kuj tuaj yeem degraded los ntawm enzymes, uas qhia tau hais tias cov degree ntawm kev hloov ntawm txhua pab pawg neeg nyob rau hauv lub cellulose saw tsis sib npaug, thiab cov kab mob tuaj yeem erode nyob ze unsubstituted anhydroglucose pawg los tsim. qab zib, uas tuaj yeem nqus tau los ntawm cov kab mob ua zaub mov. Yog li, yog tias qib ntawm ether hloov ntawm cellulose nce, qhov kev tiv thaiv ntawm cellulose ethers rau enzymatic nres yuav nce. Nws tau tshaj tawm tias nyob rau hauv kev tswj xyuas, hydroxypropyl methylcellulose (DS = 1.9), methylcellulose (DS = 1.83), methylcellulose (DS = 1.66), hydroxyethylcellulose (1.7%) Cov viscosities seem yog 13.2%, 7.3%, 3.8% thiab 1.7% raws. Hydroxypropyl methylcellulose muaj zog tiv thaiv enzyme muaj peev xwm. Nws tuaj yeem pom tau tias hydroxypropyl methylcellulose muaj cov enzyme zoo heev, ua ke nrog nws qhov zoo dispersion, thickening thiab film-forming zog, nws tuaj yeem siv rau hauv emulsion txheej, thiab lwm yam, thiab feem ntau tsis tas yuav tsum tau ntxiv cov tshuaj tua kab mob. Txawm li cas los xij, txhawm rau tiv thaiv kev daws teeb meem los ntawm kev khaws cia ntev lossis muaj peev xwm ua rau sab nraud, cov tshuaj tua kab mob tuaj yeem raug ntxiv, thiab kev xaiv cov tshuaj tua kab mob tuaj yeem txiav txim siab raws li qhov yuav tsum tau ua ntawm kev daws teeb meem kawg. Phenylmercuric acetate thiab manganese fluorosilicate yog cov tshuaj tiv thaiv zoo, tab sis lawv muaj tshuaj lom thiab yuav tsum tau saib xyuas. Feem ntau, 1 mus rau 5 mg ntawm phenylmercuric acetate tuaj yeem muab ntxiv rau txhua liter ntawm kev daws.
7. Kev ua tau zoo ntawm hydroxypropyl methylcellulose membrane
Hydroxypropyl methylcellulose film-forming zog Hydroxypropyl methylcellulose muaj cov yeeb yaj kiab zoo heev. Thaum nws cov tshuaj aqueous lossis cov kuab tshuaj organic yog coated rau ntawm iav phaj, nws dhau los ua cov xim tsis muaj xim, pob tshab thiab tawv tawv tom qab ziab. . Nws muaj cov dej noo zoo thiab tseem ruaj khov ntawm qhov kub thiab txias. Yog tias hygroscopic plasticizers ntxiv, qhov elongation thiab yoog raws tuaj yeem txhim kho, thiab kev hloov pauv tuaj yeem txhim kho. Plasticizers xws li glycerol thiab sorbitol yog qhov tsim nyog tshaj plaws. Qhov kev daws teeb meem dav dav yog 2% ~ 3%, thiab cov tshuaj yas yas yog 10% ~ 20% ntawm cellulose ether. Yog hais tias cov ntsiab lus plasticizer yuav tsum siab, colloid syneresis yuav tshwm sim nyob rau hauv high humidity. Lub zog tensile ntawm zaj duab xis nrog plasticizer ntxiv yog ntau dua li ntawm cov yeeb yaj kiab uas tsis muaj plasticizer, thiab nws nce nrog cov nyiaj ntxiv ntawm plasticizer. Lub hygroscopicity ntawm zaj duab xis kuj nce nrog tus nqi ntawm plasticizer.
Post lub sij hawm: Feb-01-2024