Hydroxypropyl methylcellulosendi mtundu wa non-ionic cellulose wosakaniza ether. Mosiyana ndi ionic methyl carboxymethyl cellulose ether yosakanikirana, sichimakhudzana 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 kamakhala pafupi ndi ka methyl cellulose, pomwe magwiridwe antchito a methoxyl otsika komanso kuchuluka kwa hydroxyl methylpropy ya cellulopy yapafupi kwambiri ya hydroxypropyl. Komabe, muzosiyanasiyana, ngakhale kuti pali gulu laling'ono chabe la hydroxypropyl kapena gulu laling'ono la methoxyl, pali kusiyana kwakukulu kwa kusungunuka kwa zosungunulira za organic kapena kutentha kwa flocculation mu njira zamadzimadzi.
(1) Kusungunuka kwa hydroxypropyl methylcellulose
① Kusungunuka kwa hydroxypropyl methylcellulose m'madziHydroxypropyl methylcellulosekwenikweni ndi mtundu wa methylcellulose wosinthidwa ndi propylene oxide (methoxy-propylene), kotero imakhalabe ndi zinthu zomwezo monga methyl cellulose ili ndi makhalidwe ofanana a kusungunuka kwa madzi ozizira ndi kusungunuka kwa madzi 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 amadzimadzi solution ndi 2% methoxy content substitution degree DS=0.73 ndi hydroxypropyl content MS=0.46 ndi 500 mpa·s pa 20°C, ndi kutentha gel osakaniza Ikhoza kufika pafupi 100°C, pamene methyl5 ° C cellulose yomweyo ndi pa cellulose yomweyo. Ponena za kusungunuka kwake m'madzi, zasinthidwanso kwambiri. Mwachitsanzo, pulverized hydroxypropyl methylcellulose (granular mawonekedwe 0.2 ~ 0.5mm pa 20 ° C ndi 4% amadzimadzi kukhuthala 2pa•s akhoza kugulidwa pa firiji, ndi mosavuta sungunuka m'madzi popanda kuzirala.
② Kusungunuka kwa hydroxypropyl methylcellulose mu organic solvents kusungunuka kwa hydroxypropyl methylcellulose mu zosungunulira organic kulinso kwabwino kuposa methylcellulose. Methylcellulose ayenera kukhala ndi methoxyl m'malo digiri ya 2.1 mankhwala pamwamba, koma munali hydroxypropyl MS = 1.5 ~ 1.8 ndi methoxy DS = 0.2 ~ 1.0, mkulu-makamakamakamakamakamakamakamakamakamakayendedwe hydroxypropyl methylcellulose ndi okwana digiri ya m'malo pamwamba 1.8 ndi kusungunuka methanoshydro ndi annol hydrocarbon. thermos-pulasitiki ndi kusungunuka kwamadzi. 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 Kuwoneka kwa Hydroxypropyl Methyl Cellulose Kutsimikiza kwa viscosity ya hydroxypropyl methyl cellulose ndi yofanana ndi ya ma cellulose ethers. 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 kutsika, 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 viscosity kupatula kuthekera kwa kuwonongeka kwa enzymatic.
(3) Kulekerera kwa mchere wa hydroxypropyl methylcellulose Popeza hydroxypropyl methylcellulose ndi ether yosakhala ionic, siipangidwa ndi ionized m'madzi, mosiyana ndi ma ionic cellulose ethers, monga carboxymethyl Base cellulose, mu njira yothetsera zitsulo zolemera zitsulo ndi mpweya. Mchere wambiri monga chloride, bromide, phosphate, nitrate, ndi zina zotero. Komabe, kuwonjezera mchere ali ndi chikoka pa flocculation kutentha ake amadzimadzi njira. Pamene ndende mchere ukuwonjezeka, gel osakaniza kutentha amachepetsa. Pamene mchere ndende ndi pansi pa flocculation mfundo, ndi mamasukidwe akayendedwe a yankho amakonda kuwonjezeka. Choncho, mchere wambiri umawonjezedwa, pogwiritsira ntchito, ukhoza kukwaniritsa kuwonjezereka kwachuma. Choncho, mu ntchito zina, ndi bwino kugwiritsa ntchito chisakanizo cha cellulose ether ndi mchere kusiyana ndi njira yowonjezera ya ether kuti ikwaniritse thickening kwenikweni.
(4) Hydroxypropyl methylcellulose acid ndi alkali resistance Hydroxypropyl methylcellulose nthawi zambiri imakhala yokhazikika ku ma acid ndi alkalis, ndipo sichikhudzidwa 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.
(5) Miscibility ya hydroxypropyl methylcellulose Hydroxypropyl methylcellulose yankho akhoza kusakaniza ndi madzi sungunuka polima mankhwala kukhala yunifolomu ndi mandala njira ndi apamwamba mamasukidwe akayendedwe. Ma polima awa amaphatikiza polyethylene glycol, polyvinyl acetate, polysilicone, polymethylvinyl siloxane, 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.
(6) Kusungunuka m'madzi kosasungunukama cellulose etherswa hydroxypropyl methylcellulose amatha kulumikiza pamwamba ndi ma aldehydes, kotero kuti ma ether osungunuka m'madziwa amawomberedwa munjirayo ndikukhala osasungunuka m'madzi. Ma aldehydes omwe amapanga hydroxypropyl methylcellulose osasungunuka amaphatikizapo formaldehyde, glyoxal, succinic aldehyde, adipaldehyde, ndi zina zotero. Mukamagwiritsa ntchito formaldehyde, chisamaliro chapadera chiyenera kuperekedwa ku pH ya yankho, yomwe glyoxal imachita mofulumira, kotero glyoxal imagwiritsidwa ntchito popanga ma crosslinking mafakitale. Mlingo wamtundu 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. Nthawi zambiri, kutentha kwa mankhwala ndi 0 ~ 30 ℃, ndipo nthawi ndi 1 ~ 120min. Kuphatikizikako kuyenera kuchitika pansi pa acidic. Nthawi zambiri, pH ya yankho imasinthidwa kukhala pafupifupi 2 ~ 6 powonjezera asidi amphamvu kapena organic carboxylic acid ku yankho, makamaka pakati pa 4 ~ 6, kenako ma aldehydes amawonjezedwa kuti achitepo kanthu. Zomwe zimagwiritsidwa ntchito zimakhala ndi hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxy-acetic acid, succinic acid kapena citric acid etc., momwemo ndi formic acid kapena acetic acid ndizoyenera, 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. Pambuyo pa cellulose ether ndi yosasungunuka, ndizosavuta kugwiritsa ntchito.
20 ~ 25 ℃ madzi ochapira ndi kuyeretsa. 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.
(7) Kukaniza kwa enzyme ya hydroxypropyl methylcellulose ndi zotumphukira zama cellulose, monga gulu lililonse la anhydroglucose, ngati pali gulu logwirizana lolowa m'malo, sikophweka kutenga kachilomboka ndi tizilombo tating'onoting'ono, koma kwenikweni mankhwala omalizidwa. unyolo si yunifolomu mokwanira, ndipo tizilombo akhoza kukokoloka pa unsubstituted anhydroglucose gulu kupanga shuga, monga zakudya kuti tizilombo kuyamwa. Choncho, ngati mlingo wa etherification m'malo mwa cellulose ukuwonjezeka, kukana kwa enzymatic kukokoloka kwa mapadi ether kudzachulukanso. Malinga ndi malipoti, pansi pazikhalidwe zolamuliridwa, zotsatira za hydrolysis za michere yopangidwa, 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 hydroxyethyl%, cellulose 3.8%. 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 chisankhocho chikhoza kutsimikiziridwa malinga ndi zofunikira zomaliza za yankho. Phenylmercuric acetate ndi manganese fluorosilicate ndi zoteteza 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.
(8) Kuchita kwahydroxypropyl methylcellulosefilimu Hydroxypropyl methylcellulose ili ndi zinthu zabwino kwambiri zopanga 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 yokhala ndi plasticizer yowonjezeredwa ndi yayikulu kwambiri kuposa yopanda pulasitiki, ndipo imawonjezeka ndi kuchuluka kwa ndalama zowonjezera. Ponena za hygroscopicity ya filimuyi, imawonjezekanso ndi kuwonjezeka kwa kuchuluka kwa plasticizer.
Nthawi yotumiza: Apr-25-2024