Thepa ea hydroxypropyl methylcellulose

Hydroxypropyl methylcellulose HPMC ke mofuta oa non-ionic cellulose motsoako oa ether.Ho fapana le ionic methyl carboxymethyl cellulose motsoako oa ether, ha e sebetsane le litšepe tse boima.Ka lebaka la likarohano tse fapaneng tsa methoxyl content le hydroxypropyl content ho hydroxypropyl methylcellulose le viscosities tse fapaneng, ho na le mefuta e mengata e nang le thepa e fapaneng, mohlala, methoxyl e phahameng le litaba tse tlase tsa hydroxypropyl Ts'ebetso ea eona e haufi le ea methyl cellulose, athe e tlase. Methoxyl le dikahare tse phahameng tsa hydroxypropyl li haufi le tsa hydroxypropyl methyl cellulose.Leha ho le joalo, mofuteng o mong le o mong, le hoja ho na le palo e nyenyane feela ea sehlopha sa hydroxypropyl kapa sehlopha se senyenyane sa methoxyl, ho na le phapang e kholo ea ho qhibiliha ha metsoako ea lintho tse phelang kapa mocheso oa flocculation ka tharollo ea metsi.

(1) Lintho tsa ho qhibiliha ha hydroxypropyl methylcellulose

①Solubility ea hydroxypropyl methylcellulose ka metsing Hydroxypropyl methylcellulose ha e le hantle ke mofuta oa methylcellulose e fetotsoeng ke propylene oxide (methoxypropylene), kahoo e ntse e na le thepa e ts'oanang le ea methyl cellulose Cellulose e na le litšobotsi tse ts'oanang tsa ho qhibiliha ha metsi a batang le ho se kenelle ha metsi a chesang.Leha ho le joalo, ka lebaka la sehlopha se fetotsoeng sa hydroxypropyl, mocheso oa eona oa gelation metsing a chesang o phahame haholo ho feta oa methyl cellulose.Mohlala, viscosity ea hydroxypropyl methylcellulose aqueous solution e nang le 2% methoxy content substitution degree DS=0.73 le hydroxypropyl content MS=0.46 ke 500 mpa·s ho 20°C, le mocheso oa eona oa gel E ka fihla haufi le 100°C, athe methyl cellulose mochesong o tšoanang e ka ba 55°C feela.Ha e le ho qhibiliha ha eona metsing, le eona e ntlafalitsoe haholo.Mohlala, hydroxypropyl methylcellulose e entsoeng ka granular (sebopeho sa granular 0.2 ~ 0.5mm ho 20 ° C se nang le viscosity ea 4% ea aqueous ea 2pa•s e ka rekoa Mocheng oa kamore, e qhibiliha habonolo metsing ntle le ho pholile.

②Solubility ea hydroxypropyl methylcellulose in organic solvents Ho qhibiliha ha hydroxypropyl methylcellulose ka har'a metsoako ea lintho tse phelang le hona ho molemo ho feta ea methylcellulose.Bakeng sa lihlahisoa tse ka holimo ho 2.1, high-viscosity hydroxypropyl methylcellulose e nang le hydroxypropyl MS = 1.5 ~ 1.8 le methoxy DS=0.2 ~ 1.0, e nang le tekanyo e feletseng ea sebaka se ka holimo ho 1.8, e qhibiliha ka methanol ea anhydrous le ethanol Medium, le metsi a thermoluble. .E boetse e qhibiliha ka har'a hydrocarbons ea chlorine joalo ka methylene chloride le chloroform, le lihlapolli tsa tlhaho tse kang acetone, isopropanol le diacetone joala.Ho qhibiliha ha eona ka har'a metsoako ea tlhaho ho molemo ho feta ho qhibiliha ha metsi.

(2) Lintho tse amang viscosity ea hydroxypropyl methylcellulose Boikemisetso bo tloaelehileng ba viscosity ea hydroxypropyl methylcellulose bo tšoana le li-cellulose ethers tse ling, 'me li lekanyetsoa ho 20 ° C ka tharollo ea 2% ea metsi e le tekanyetso.Viscosity ea sehlahisoa se tšoanang e eketseha ka ho eketseha ha mahloriso.Bakeng sa lihlahisoa tse nang le litekanyo tse fapaneng tsa limolek'hule sebakeng se le seng, sehlahisoa se nang le boima bo boholo ba limolek'hule se na le viscosity e phahameng.Kamano ea eona le mocheso e tšoana le ea methyl cellulose.Ha mocheso o phahama, viscosity e qala ho fokotseha, empa ha e fihla mocheso o itseng,

viscosity e phahama ka tšohanyetso 'me gelation e etsahala.Mocheso oa gel oa lihlahisoa tse tlaase-viscosity o phahame.e phahame.Ntlha ea eona ea gel ha e amane feela le viscosity ea ether, empa hape e amana le karolelano ea motsoako oa sehlopha sa methoxyl le sehlopha sa hydroxypropyl ka ether le boholo ba tekanyo ea kakaretso ea ho fetola.Hoa lokela ho hlokomeloa hore hydroxypropyl methylcellulose le eona ke pseudoplastic, 'me tharollo ea eona e tsitsitse mocheso oa kamore ntle le ho senyeha ha viscosity ntle le monyetla oa ho senyeha ha enzymatic.

(3) Mamello ea letsoai ea hydroxypropyl methylcellulose Kaha hydroxypropyl methylcellulose ke ether e seng ea ionic, ha e ionize ka har'a mecha ea litaba ea metsi, ho fapana le li-ether tse ling tsa ionic cellulose, Ka mohlala, carboxymethyl cellulose e sebetsana le li-ion tse boima tsa tšepe 'me e phalla ka ntle ho tharollo.Matsoai a akaretsang a kang chloride, bromide, phosphate, nitrate, joalo-joalo a ke ke a putlama ha a eketsoa mothapong oa eona oa metsi.Leha ho le joalo, ho phaella ha letsoai ho na le tšusumetso e itseng ho mocheso oa flocculation oa tharollo ea eona ea metsi.Ha letsoai le ntse le eketseha, mocheso oa gel o fokotseha.Ha letsoai le le ka tlas'a ntlha ea flocculation, viscosity ea tharollo e atisa ho eketseha.Ka hona, tekanyo e itseng ea letsoai e kenngoa., ha e sebelisoa, e ka finyella phello ea thickening ho feta moruo.Ka hona, lits'ebetsong tse ling, ho molemo ho sebelisa motsoako oa cellulose ether le letsoai ho feta motsoako o phahameng oa tharollo ea ether ho finyella phello e teteaneng.

(4) Hydroxypropyl methylcellulose acid le alkali resistance Hydroxypropyl methylcellulose ka kakaretso e tsitsitse ho li-acids le alkalis, 'me ha e amehe ka har'a pH 2 ~ 12.E ka mamella palo e itseng ea Li-acids tsa Leseli, tse kang formic acid, acetic acid, citric acid, succinic acid, phosphoric acid, boric acid, joalo-joalo Empa acid e concentrated e na le phello ea ho fokotsa viscosity.Li-alkali tse kang caustic soda, potash ea caustic le metsi a lime ha li na phello ho eona, empa li ka eketsa viscosity ea tharollo hanyenyane, ebe li fokotsa butle-butle.

(5) Miscibility ea hydroxypropyl methylcellulose Hydroxypropyl methylcellulose tharollo e ka kopanngoa le metsoako ea polymer e qhibilihang ka metsi hore e be tharollo e ts'oanang le e hlakileng e nang le viscosity e phahameng.Metsoako ena ea polymer e kenyelletsa polyethylene glycol, polyvinyl acetate, polysilicone, polymethylvinylsiloxane, hydroxyethyl cellulose, le methyl cellulose.Metsoako ea tlhaho e phahameng ea limolek'hule joalo ka gum arabic, tsie bean gum, karaya gum, joalo-joalo le eona e na le tumellano e ntle le tharollo ea eona.Hydroxypropyl methylcellulose e ka boela ea tsoakoa le mannitol ester kapa sorbitol ester ea stearic acid kapa palmitic acid, hape e ka tsoakoa le glycerin, sorbitol le mannitol, 'me metsoako ena e ka sebelisoa e le hydroxypropyl methylcellulose Plasticizer bakeng sa selulose.

(6) Insoluble water-soluble cellulose ethers tsa hydroxypropyl methylcellulose li ka amahanngoa le aldehydes holim'a metsi, e le hore li-ether tsena tse qhibilihang ka metsi li tšeloe ka tharollo 'me li se ke tsa qhibiliha metsing.Li-aldehyde tse etsang hore hydroxypropyl methylcellulose e se ke ea qhibiliha li kenyelletsa formaldehyde, glyoxal, succinic aldehyde, adipaldehyde, joalo-joalo Ha u sebelisa formaldehyde, tlhokomelo e khethehileng e lokela ho lefshoa ho boleng ba pH ba tharollo, eo glyoxal e arabelang ka potlako ka eona, kahoo glyoxal e atisa ho sebelisoa e le crosslink. moemeli tlhahiso ea indasteri.Palo ea mofuta ona oa li-cross-linking agent ka tharollo ke 0.2% ~ 10% ea boima ba ether, haholo-holo 7% ~ 10%, mohlala, 3.3% ~ 6% ea glyoxal ke eona e loketseng ka ho fetisisa.Ka kakaretso, phekolo

mocheso ke 0 ~ 30 ℃, 'me nako ke 1 ~ 120min.Karabelo ea li-cross-linking e lokela ho etsoa tlas'a maemo a acidic.Ka kakaretso, tharollo e qala ka ho eketsoa ka asiti e matla ea inorganic kapa organic carboxylic acid ho lokisa pH ea tharollo ho hoo e ka bang 2 ~ 6, haholo-holo pakeng tsa 4 ~ 6, ebe o eketsa aldehydes ho phethahatsa karabelo e kopanyang.Asiti e sebelisitsoeng e na le hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxyacetic acid, succinic acid kapa citric acid joalo-joalo, moo ka acid ea formic kapa acetic acid e leng bohlale, le formic acid e nepahetse.Asiti le aldehyde le tsona li ka eketsoa ka nako e le 'ngoe ho lumella tharollo hore e be le karabelo e hokahanyang ka har'a mofuta o lakatsehang oa pH.Hangata karabelo ena e sebelisoa ts'ebetsong ea ho qetela ea phekolo nakong ea ho lokisoa ha cellulose ethers.Kamora hore cellulose ether e se ke ea qhibiliha, ho bonolo ho e sebelisa

20 ~ 25 ℃ metsi bakeng sa ho hlatsoa le ho hloekisa.Ha sehlahisoa se sebelisoa, lintho tsa alkaline li ka kenngoa tharollong ea sehlahisoa ho fetola pH ea tharollo hore e be alkaline, 'me sehlahisoa se tla qhibiliha ka tharollo kapele.Mokhoa ona o boetse o sebetsa ho phekola filimi ka mor'a hore tharollo ea cellulose ether e etsoe filimi ho e etsa filimi e sa tsitsang.

(7) Ho hanyetsa ha enzyme ea hydroxypropyl methylcellulose ke theoretically cellulose derivatives, joalo ka sehlopha se seng le se seng sa anhydroglucose, haeba ho na le sehlopha se nkang sebaka se tiileng, ha ho bonolo ho tšoaetsoa ke likokoana-hloko, empa ha e le hantle sehlahisoa se felile Ha boleng ba sebaka bo feta. 1, e tla boela e nyenyefatsoe ke li-enzyme, ho bolelang hore tekanyo ea ho nkela sehlopha ka seng sebaka sa ketane ea cellulose ha e tšoane ka ho lekana, 'me likokoana-hloko li ka senyeha sehlopheng se sa nkeng sebaka sa anhydroglucose ho theha tsoekere, e le limatlafatsi bakeng sa likokoana-hloko ho monya.Ka hona, haeba tekanyo ea etherification substitution ea selulose e eketseha, ho hanyetsa khoholeho ea enzymatic ea cellulose ether le eona e tla eketseha.Ho ea ka litlaleho, tlas'a maemo a laoloang, liphello tsa hydrolysis tsa li-enzyme, li-viscosity tse setseng tsa hydroxypropyl methylcellulose (DS = 1.9) ke 13.2%, methylcellulose (DS = 1.83) ke 7.3%, methylcellulose (DS = 1.66) ke 3.8%. le selulose ea hydroxyethyl ke 1.7%.Ho ka bonoa hore hydroxypropyl methylcellulose e na le matla a matla a anti-enzyme.Ka hona, khanyetso e ntle ea enzyme ea hydroxypropyl methylcellulose, e kopantsoeng le thepa ea eona e ntle ea dispersibility, thickening le filimi-forming, e sebelisoa ka liphahlo tsa metsi-emulsion, joalo-joalo, 'me ka kakaretso ha ho hlokahale ho eketsa li-preservatives.Leha ho le joalo, bakeng sa polokelo ea nako e telele ea tharollo kapa tšilafalo e ka 'nang ea e-ba teng ka ntle, li-preservatives li ka eketsoa e le tšireletso,' me khetho e ka khethoa ho ea ka litlhoko tsa ho qetela tsa tharollo.Phenylmercuric acetate le manganese fluorosilicate ke li-preservatives tse sebetsang hantle, empa kaofela li na le Chefo, tlhokomelo e tlameha ho lefshoa ts'ebetsong.Ka kakaretso, 1 ~ 5mg ea phenylmercury acetate e ka ekeletsoa ho tharollo ka litha e le nngwe ea litekanyetso.

(8) Ts'ebetso ea filimi ea hydroxypropyl methylcellulose Hydroxypropyl methylcellulose e na le thepa e ntle haholo ea ho etsa lifilimi.Tharollo ea eona e nang le metsi kapa motsoako oa motsoako oa tlhaho o koahetsoe holim'a poleiti ea khalase, 'me e fetoha e se nang mebala le e hlakileng ka mor'a ho omisa.Le filimi e thata.E na le khanyetso e ntle ea mongobo 'me e lula e tiile mocheso o phahameng.Haeba hygroscopic plasticizer e eketsoa, ​​bolelele ba eona le ho tenyetseha ha eona ho ka ntlafatsoa.Mabapi le ho ntlafatsa ho feto-fetoha ha maemo, li-plasticizers tse kang glycerin le sorbitol ke tsona tse loketseng ka ho fetisisa.Ka kakaretso, mahloriso a tharollo ke 2% ~ 3%, 'me palo ea plasticizer ke 10% ~ 20% ea cellulose ether.Haeba litaba tsa plasticizer li phahame haholo, ho fokotseha ha colloidal dehydration ho tla etsahala ka mongobo o phahameng.Matla a tsitsipano a filimi ka

plasticizer e kenyellelitsoeng e kholo haholo ho feta ntle le polasetiki, 'me e eketseha ka keketseho ea palo e ekelitsoeng.Ha e le hygroscopicity ea filimi, e boetse e eketseha ka keketseho ea palo ea polasetiki.