Hydroxypropyl methylcellulose HPMC ndi mtundu wa non-ionic cellulose wosakanizidwa ether. Mosiyana ndi ionic methyl carboxymethyl cellulose ether wosakanizidwa, sichita ndi zitsulo zolemera. Chifukwa cha kusiyanasiyana kwa methoxyl ndi hydroxypropyl zomwe zili mu hydroxypropyl methylcellulose ndi ma viscosities osiyanasiyana, pali mitundu yambiri yokhala ndi zinthu zosiyanasiyana, mwachitsanzo, kuchuluka kwa methoxyl komanso kutsika kwa hydroxypropyl Kachitidwe kake kakufanana ndi ka cellulose ya methyl, pomwe ntchito ya Methoxy yotsika komanso kuchuluka kwa hydroxypropyl kuli pafupi ndi ya hydroxypropyl methyl cellulose. Komabe, muzosiyanasiyana, ngakhale kuti pali gulu laling'ono la hydroxypropyl kapena gulu laling'ono la methoxyl, kusungunuka kwa zosungunulira za organic kapena kutentha kwa flocculation mu njira yamadzimadzi ndizosiyana kwambiri.
1. Kusungunuka kwa hydroxypropyl methylcellulose
①Kusungunuka kwa hydroxypropyl methylcellulose m'madzi Hydroxypropyl methylcellulose kwenikweni ndi mtundu wa methylcellulose wosinthidwa ndi propylene oxide (methoxypropylene), kotero imakhalabe ndi zinthu zomwezo monga methyl cellulose Cellulose ili ndi mawonekedwe ofanana ndi kusungunuka kwamadzi ozizira komanso kusasungunuka kwamadzi otentha. Komabe, chifukwa cha gulu losinthidwa la hydroxypropyl, kutentha kwake kwa gelation m'madzi otentha ndikokwera kwambiri kuposa methyl cellulose. Mwachitsanzo, kukhuthala kwa hydroxypropyl methylcellulose aqueous solution ndi 2% methoxy content substitution degree DS=0.73 ndi hydroxypropyl content MS=0.46 ndi chopangidwa ndi 500 mpa?s pa 20°C, ndi kutentha kwa gel osakaniza Kumatha kufika pafupifupi 100° C, pamene methyl cellulose pa kutentha komweko ndi pafupifupi 55 ° C. Ponena za kusungunuka kwake m'madzi, zakonzedwanso kwambiri. Mwachitsanzo, pulverized hydroxypropyl methylcellulose (chinthu chokhala ndi kukula kwa 0.2 ~ 0.5mm ndi 4% yamadzimadzi amadzimadzi kukhuthala kwa 2pa?s pa 20 ° C zitha kugulidwa Kutentha, zimasungunuka mosavuta m'madzi popanda kuzirala. .
②Kusungunuka kwa hydroxypropyl methylcellulose mu organic solvents Kusungunuka kwa hydroxypropyl methylcellulose mu zosungunulira za organic kulinso bwino kuposa methylcellulose. Zazinthu zopitilira 2.1,high-viscosity hydroxypropyl methylcellulosemunali hydroxypropyl MS = 1.5 ~ 1.8 ndi methoxy DS = 0.2 ~ 1.0, ndi digiri okwana m'malo pamwamba 1.8, ndi sungunuka mu anhydrous methanol ndi Mowa njira Yapakatikati, ndi thermoplastic ndi madzi sungunuka. Imasungunukanso mu ma hydrocarboni a chlorine monga methylene chloride ndi chloroform, ndi zosungunulira organic monga acetone, isopropanol ndi diacetone mowa. Kusungunuka kwake mu zosungunulira za organic ndikwabwino kuposa kusungunuka kwamadzi.
2. Zinthu zomwe zimakhudza kukhuthala kwa hydroxypropyl methylcellulose
Zomwe Zimapangitsa Kuwoneka kwa Makanema a Hydroxypropyl Methyl Cellulose Kutsimikiza kwa kukhuthala kwa hydroxypropyl methyl cellulose ndikofanana ndi ma cellulose ethers ena. Imayezedwa pa 20 ° C ndi 2% yankho lamadzi monga muyezo. Kukhuthala kwa mankhwala omwewo kumawonjezeka ndi kuwonjezeka kwa ndende. Kwa mankhwala omwe ali ndi zolemetsa zosiyanasiyana pamagulu omwewo, mankhwala omwe ali ndi kulemera kwakukulu kwa maselo amakhala ndi kukhuthala kwakukulu. Ubale wake ndi kutentha ndi wofanana ndi wa methyl cellulose. Kutentha kumakwera, kukhuthala kumayamba kuchepa, koma ikafika kutentha kwina, kukhuthala kumatuluka mwadzidzidzi ndipo gelation imachitika. Kutentha kwa gel otsika-kukhuthala kwakanthawi ndikokwera kwambiri. ndi mkulu. Mfundo yake ya gel sikuti imangogwirizana ndi kukhuthala kwa ether, komanso yokhudzana ndi kuchuluka kwa gulu la methoxyl ndi gulu la hydroxypropyl mu ether komanso kukula kwa digiri yonse yolowa m'malo. Tiyenera kuzindikira kuti hydroxypropyl methylcellulose imakhalanso pseudoplastic, ndipo yankho lake ndi lokhazikika kutentha kwa firiji popanda kuwonongeka kwa mamasukidwe akayendedwe kupatula kuthekera kwa kuwonongeka kwa enzymatic.
3. Hydroxypropyl methylcellulose imagonjetsedwa ndi asidi ndi alkali
Hydroxypropyl methylcellulose acid ndi alkali resistance Hydroxypropyl methylcellulose nthawi zambiri imakhala yokhazikika ku ma acid ndi alkalis, ndipo samakhudzidwa ndi pH 2 ~ 12. Ikhoza kupirira kuchuluka kwa asidi kuwala, monga formic acid, asidi acetic, citric acid, succinic acid, asidi phosphoric, asidi boric, etc. Koma moyikira asidi ali ndi zotsatira za kuchepetsa mamasukidwe akayendedwe. Alkalis monga caustic soda, caustic potashi ndi madzi a mandimu alibe mphamvu pa izo, koma amatha kuonjezera kukhuthala kwa yankho, ndiyeno pang'onopang'ono kuchepetsa.
4. Kusokonezeka kwa hydroxypropyl methylcellulose
Miscibility wa hydroxypropyl methylcellulose Hydroxypropyl methylcellulose njira akhoza kusakaniza ndi madzi sungunuka polima mankhwala kukhala yunifolomu ndi mandala njira ndi kukhuthala apamwamba. Ma polima awa amaphatikiza polyethylene glycol, polyvinyl acetate, polysilicone, polymethylvinylsiloxane, hydroxyethyl cellulose, ndi methyl cellulose. Zosakaniza zachilengedwe monga chingamu cha arabic, dzombe chingamu, chingamu cha karaya, ndi zina zotero, zimagwirizananso bwino ndi yankho lake. Hydroxypropyl methylcellulose imathanso kusakanizidwa ndi mannitol ester kapena sorbitol ester ya stearic acid kapena palmitic acid, komanso imatha kusakanikirana ndi glycerin, sorbitol ndi mannitol, ndipo mankhwalawa angagwiritsidwe ntchito ngati hydroxypropyl methylcellulose Plasticizer ya cellulose.
5. Insolubilization ndi kusungunuka kwa madzi kwa hydroxypropyl methylcellulose
Ma cellulose ethers osasungunuka m'madzi a hydroxypropyl methylcellulose amatha kulumikizidwa ndi ma aldehydes pamtunda, kotero kuti ma ether osungunuka m'madziwa amalowetsedwa munjirayo ndikukhala osasungunuka m'madzi. Ma aldehydes omwe amapanga hydroxypropyl methylcellulose osasungunuka amaphatikizapo formaldehyde, glyoxal, succinic aldehyde, adipaldehyde, ndi zina. Mukamagwiritsa ntchito formaldehyde, chidwi chapadera chiyenera kuperekedwa ku pH ya yankho, yomwe glyoxal imachita mofulumira, kotero glyoxal amagwiritsidwa ntchito ngati crosslinking. wothandizira pakupanga mafakitale. Kuchuluka kwa mtundu woterewu wolumikizana nawo mu yankho ndi 0,2% ~ 10% ya unyinji wa ether, makamaka 7% ~ 10%, mwachitsanzo, 3.3% ~ 6% ya glyoxal ndi yoyenera kwambiri. Kutentha kwamankhwala ambiri ndi 0 ~ 30 ℃, ndipo nthawi ndi 1 ~ 120min. Kuphatikizika kolumikizana kuyenera kuchitika pansi pa acidic. Nthawi zambiri, yankho limayamba kuwonjezeredwa ndi asidi amphamvu kapena organic carboxylic acid kuti musinthe pH ya yankho kukhala pafupifupi 2 ~ 6, makamaka pakati pa 4 ~ 6, kenako ndikuwonjezera ma aldehydes kuti achite zomwe zimalumikizana. Zomwe zimagwiritsidwa ntchito zimakhala ndi hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxyacetic acid, succinic acid kapena citric acid etc., momwemo ndi formic acid kapena acetic acid ndi bwino, ndipo formic acid ndi yabwino. Asidi ndi aldehyde amathanso kuwonjezeredwa nthawi imodzi kuti alole yankho kuti ligwirizane ndi njira yolumikizirana pakati pa pH yomwe mukufuna. Izi nthawi zambiri amagwiritsidwa ntchito pomaliza chithandizo pokonzekera ma cellulose ethers. Ether ya cellulose ikatha kusungunuka, ndikosavuta kutsuka ndikutsuka ndi madzi pa 20 ~ 25 ° C. Mankhwalawa akagwiritsidwa ntchito, zinthu zamchere zimatha kuwonjezeredwa ku yankho la mankhwalawa kuti zisinthe pH ya yankho kuti ikhale yamchere, ndipo mankhwalawa amasungunuka mwachangu. Njirayi imagwiranso ntchito pochiza filimuyo pambuyo poti njira ya cellulose ether imapangidwira filimu kuti ikhale filimu yosasungunuka.
6. Kukana kwa enzyme ya hydroxypropyl methylcellulose
Kukaniza kwa enzyme ya hydroxypropyl methylcellulose ndikochokera ku cellulose, monga gulu lililonse la anhydroglucose, ngati pali gulu lokhazikika lokhazikika, sikophweka kutenga kachilomboka ndi tizilombo tating'onoting'ono, koma kwenikweni mankhwala omalizidwa Pamene mtengo wolowa m'malo umaposa 1, idzadetsedwanso ndi michere, zomwe zikutanthauza kuti kuchuluka kwa kulowetsedwa kwa gulu lililonse pa unyolo wa cellulose sikuli kofanana mokwanira, ndipo tizilombo toyambitsa matenda titha kuwononga gulu losalowa m'malo la anhydroglucose kupanga shuga, monga zakudya zopatsa tizilombo toyambitsa matenda. Choncho, ngati mlingo wa etherification m'malo mwa cellulose ukuwonjezeka, kukana kwa enzymatic kukokoloka kwa mapadi ether kudzachulukanso. Malinga ndi malipoti, pansi pamikhalidwe yoyendetsedwa, zotsatira za hydrolysis za michere, kukhuthala kotsalira kwa hydroxypropyl methylcellulose (DS = 1.9) ndi 13.2%, methylcellulose (DS = 1.83) ndi 7.3%, methylcellulose (DS = 1.66) ndi 3.8%, ndi hydroxyethyl cellulose ndi 1.7%. Zitha kuwoneka kuti hydroxypropyl methylcellulose ili ndi mphamvu yotsutsa ma enzyme. Choncho, kukana kwambiri kwa enzyme ya hydroxypropyl methylcellulose, kuphatikizapo dispersibility yake yabwino, thickening ndi kupanga mafilimu, amagwiritsidwa ntchito mu zokutira za emulsion zamadzi, ndi zina zotero, ndipo kawirikawiri sizifunikira kuwonjezera zotetezera. Komabe, kusungirako kwa nthawi yaitali yankho kapena kuipitsidwa kotheka kuchokera kunja, zotetezera zimatha kuwonjezeredwa ngati njira yodzitetezera, ndipo chisankho chikhoza kutsimikiziridwa molingana ndi zofunikira zomaliza za yankho. Phenylmercuric acetate ndi manganese fluorosilicate ndi zotetezera zogwira mtima, koma zonse zili ndi Toxicity, chidwi chiyenera kuperekedwa ku opaleshoniyo. Kawirikawiri, 1 ~ 5mg ya phenylmercury acetate ikhoza kuwonjezeredwa ku yankho pa lita imodzi ya mlingo.
7. Kuchita kwa hydroxypropyl methylcellulose membrane
Kachitidwe ka filimu ya hydroxypropyl methylcellulose Hydroxypropyl methylcellulose ali ndi mawonekedwe abwino kwambiri opangira mafilimu. Njira yake yamadzimadzi kapena organic solvent solution imakutidwa pa mbale yagalasi, ndipo imakhala yopanda mtundu komanso yowonekera pambuyo poyanika. Ndipo filimu yovuta. Ili ndi kukana kwabwino kwa chinyezi ndipo imakhalabe yolimba pa kutentha kwakukulu. Ngati pulasitiki wa hygroscopic wawonjezedwa, kutalika kwake ndi kusinthasintha kwake kumatha kukulitsidwa. Pankhani yosintha kusinthasintha, mapulasitiki opangira zinthu monga glycerin ndi sorbitol ndi omwe ali oyenera kwambiri. Nthawi zambiri, ndende yothetsera vutoli ndi 2% ~ 3%, ndipo kuchuluka kwa plasticizer ndi 10% ~ 20% ya cellulose ether. Ngati zomwe zili mu plasticizer ndizokwera kwambiri, kutsika kwa colloidal dehydration kudzachitika pa chinyezi chambiri. Mphamvu yolimba ya filimuyo yowonjezeredwa ndi plasticizer ndi yayikulu kwambiri kuposa iyo popanda kuwonjezera, ndipo imawonjezeka ndi kuwonjezeka kwa ndalama zowonjezera, ndipo hygroscopicity ya filimuyi imawonjezekanso ndi kuwonjezeka kwa kuchuluka kwa plasticizer.
Nthawi yotumiza: Dec-19-2022