Focus on Cellulose ethers

Hydroxypropyl Methyl Cellulose HPMC Properties

Hydroxypropyl methylcellulose HPMC rudzi rwe-non-ionic cellulose yakasanganiswa ether. Yakasiyana kubva kune ionic methyl carboxymethyl cellulose yakasanganiswa ether, haina kuita nesimbi inorema. Nekuda kwekusiyana kwakasiyana kwemethoxyl yemukati uye hydroxypropyl yemukati muhydroxypropyl methylcellulose uye akasiyana viscosities, kune akawanda marudzi ane akasiyana midziyo, semuenzaniso, yakakwira methoxyl yemukati uye yakaderera hydroxypropyl yemukati Kuita kwayo kuri pedyo neiyo methyl cellulose, nepo kuita kwe yakaderera methoxy yemukati uye yakakwira hydroxypropyl yemukati iri padyo neiyo yehydroxypropyl methyl cellulose. Nekudaro, mumhando yega yega, kunyangwe ishoma chete yeboka rehydroxypropyl kana diki remethoxyl boka ririmo, kunyungudika mune organic solvents kana tembiricha yeflocculation mune aqueous solution zvakasiyana.
 
1. Kunyungudika kwehydroxypropyl methylcellulose
①Solubility yehydroxypropyl methylcellulose mumvura Hydroxypropyl methylcellulose ichokwadi imhando yemethylcellulose yakagadziridzwa nepropylene oxide (methoxypropylene), saka ichine zvimiro zvakafanana nemethyl cellulose Cellulose ine hunhu hwakafanana hwekunyungudika kwemvura inotonhora uye kusapinda kwemvura inopisa. Nekudaro, nekuda kweiyo yakagadziridzwa hydroxypropyl boka, iyo gelation tembiricha mumvura inopisa yakakwira zvakanyanya kupfuura iyo yemethyl cellulose. Semuenzaniso, viscosity yehydroxypropyl methylcellulose aqueous solution ine 2% methoxy content substitution degree DS=0.73 uye hydroxypropyl content MS=0.46 chigadzirwa che500 mpa?s pa20°C, uye tembiricha yayo yegel Inogona kusvika pedyo ne100° C, nepo methyl cellulose patembiricha imwe chete ingangoita 55°C. Kana iri yekuparara kwayo mumvura, yakagadziridzwawo zvakanyanya. Semuyenzaniso, iyo pulverized hydroxypropyl methylcellulose (chigadzirwa chine particle size ye 0.2 ~ 0.5mm uye 4% aqueous solution viscosity ye 2pa?s pa20°C inogona kutengwa Pakakamuri tembiricha, inonyungudika nyore mumvura isingatonhodze. .
 
②Solubility yehydroxypropyl methylcellulose muorganic solvents Kunyungudika kwehydroxypropyl methylcellulose muorganic solvents zvakare kuri nani pane iyo yemethylcellulose. Zvezvigadzirwa zviri pamusoro pe2.1,high-viscosity hydroxypropyl methylcelluloseine hydroxypropyl MS=1.5 ~ 1.8 uye methoxy DS=0.2~1.0, ine dhigirii yakazara yekutsiva pamusoro pe1.8, inonyungudika muanhydrous methanol uye ethanol mhinduro Pakati, uye thermoplastic uye mvura-inonyungudika. Iyo zvakare inonyungudika mu chlorinated hydrocarbons senge methylene chloride uye chloroform, uye organic solvents senge acetone, isopropanol uye diacetone doro. Kunyungudika kwayo muorganic solvents kuri nani pane kunyungudika kwemvura.
 
2. Zvinhu zvinokanganisa viscosity yehydroxypropyl methylcellulose
Zvinhu Zvinokonzera Viscosity yeHydroxypropyl Methyl Cellulose Iyo yakajairwa viscosity kutsunga yehydroxypropyl methyl cellulose yakafanana neyeimwe cellulose ether. Inopimwa pa20°C ne2% aqueous solution seyakajairwa. Iyo viscosity yechigadzirwa chimwe chete inowedzera nekuwedzera kwehuwandu. Kune zvigadzirwa zvine huremu hwakasiyana hwema molecular pachikamu chimwe chete, chigadzirwa chine uremu hukuru hwemamorekuru chine viscosity yakakwirira. Hukama hwayo nekupisa hwakafanana neyemethyl cellulose. Kana tembiricha ichikwira, viscosity inotanga kuderera, asi kana yasvika kune imwe tembiricha, viscosity inomuka kamwe kamwe uye gelation inoitika. Iyo tembiricha yegel yezvinhu zvakaderera-viscosity yakakwira. zvakakwirira. Iyo gel point haina kungoenderana neiyo viscosity ye ether, asi zvakare inoenderana neyakaumbwa chiyero che methoxyl boka uye hydroxypropyl boka muether uye ukuru hweiyo yakazara inotsiva degree. Izvo zvinofanirwa kucherechedzwa kuti hydroxypropyl methylcellulose iri zvakare pseudoplastic, uye mhinduro yayo yakagadzikana pakamuri tembiricha pasina kushatisa muviscosity kunze kwekugona kwekukanganisa enzymatic.
 
3. Hydroxypropyl methylcellulose inopesana neasidhi uye alkali
Hydroxypropyl methylcellulose acid uye alkali resistance Hydroxypropyl methylcellulose inowanzogadzikana kune acids uye alkalis, uye haina kukanganiswa muhuwandu hwepH 2 ~ 12. Inogona kumira imwe chiyero chechiedza cheasidhi, Senge formic acid, acetic acid, citric acid, succinic acid, phosphoric acid, boric acid, etc. Asi yakanyanyisa asidhi ine mhedzisiro yekuderedza viscosity. Alkalis yakadai se caustic soda, caustic potash uye lime mvura haina simba pairi, asi inogona kuwedzera zvishoma viscosity yemhinduro, uye zvishoma nezvishoma inoderedza.
 
4. The miscibility ye hydroxypropyl methylcellulose
Miscibility yehydroxypropyl methylcellulose Hydroxypropyl methylcellulose solution inogona kusanganiswa nemvura-soluble polymer compounds kuti ive yunifomu uye yakajeka mhinduro ine viscosity yepamusoro. Aya mapolymer compounds anosanganisira polyethylene glycol, polyvinyl acetate, polysilicone, polymethylvinylsiloxane, hydroxyethyl cellulose, uye methyl cellulose. Natural high molecular compounds senge gum arabic, mhashu bhinzi gum, karaya gum, nezvimwewo zvakare zvine kuenderana kwakanaka nemhinduro yayo. Hydroxypropyl methylcellulose inogonawo kusanganiswa nemannitol ester kana sorbitol ester ye stearic acid kana palmitic acid, uye inogonawo kusanganiswa neglycerin, sorbitol uye mannitol, uye mishonga iyi inogona kushandiswa se hydroxypropyl methylcellulose Plasticizer ye cellulose.
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5. Insolubilization uye mvura solubility yehydroxypropyl methylcellulose
Iyo insoluble water-soluble cellulose ethers yehydroxypropyl methylcellulose inogona kuchinjika-yakabatana nealdehydes pamusoro, kuitira kuti aya ether-soluble ethers anonaya mumushonga uye asanyunguke mumvura. Iyo aldehydes inoita hydroxypropyl methylcellulose insoluble inosanganisira formaldehyde, glyoxal, succinic aldehyde, adipaldehyde, etc. Paunenge uchishandisa formaldehyde, kunyanya kukoshesa kunofanira kubhadharwa kune pH kukosha kwekugadzirisa, pakati peiyo glyoxal inokurumidza kukurumidza , saka glyoxal inowanzoshandiswa se crosslinking. mumiririri mukugadzirwa kwemaindasitiri. Huwandu hwemhando iyi yemuchinjiko wekubatanidza mugadziriso ndeye 0.2% ~ 10% yehuremu hweether, zviri nani 7% ~ 10%, semuenzaniso, 3.3% ~ 6% yeglyoxal ndiyo yakanyanya kufanira. Iyo yakawanda yekurapa tembiricha ndeye 0 ~ 30 ℃, uye nguva iri 1 ~ 120min. Iyo yekuyambuka-inobatanidza reaction inoda kuitwa pasi pemamiriro e acidic. Kazhinji, mhinduro inotanga yawedzerwa ne inorganic yakasimba asidhi kana organic carboxylic acid kugadzirisa pH yemushonga kusvika 2 ~ 6, zviri nani pakati pe 4 ~ 6, uye wobva wawedzera aldehydes kuita muchinjiko-inobatanidza kuita. Asidhi yakashandiswa ine hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxyacetic acid, succinic acid kana citric acid nezvimwewo, umo ine formic acid kana acetic acid inokurudzirwa, uye formic asidhi yakanaka. Iyo asidhi uye aldehyde inogona zvakare kuwedzerwa panguva imwe chete kubvumira mhinduro kuti iite muchinjiko-inobatanidza kuita mukati meinodiwa pH renji. Kuita uku kunowanzo shandiswa mukugadzirisa kwekupedzisira kwekurapa mugadziriro yekugadzira cellulose ethers. Mushure mekunge cellulose ether isinganyunguriki, zviri nyore kugeza uye kuchenesa nemvura pa20 ~ 25 ° C. Kana chigadzirwa chacho chiri kushandiswa, alkaline zvinhu zvinogona kuwedzerwa kune mhinduro yechigadzirwa kugadzirisa pH yemhinduro kuti ive alkaline, uye chigadzirwa chichanyunguduka mumhinduro nokukurumidza. Iyi nzira inoshandiswawo pakurapwa kwefirimu mushure mekunge selulosi ether solution inogadzirwa mufirimu kuti iite firimu isingagadziriswi.
 
6. Enzyme kuramba kwehydroxypropyl methylcellulose
Iyo enzyme inopikisa yehydroxypropyl methylcellulose ndeye theoretically cellulose derivatives, senge yega anhydroglucose boka, kana paine chakasimba bonded substituent boka, hazvisi nyore kutapukirwa nema microorganisms, asi chokwadi chigadzirwa chakapedzwa Kana iyo inotsiva kukosha inodarika 1, iyo. ichaderedzwawo nema enzymes, izvo zvinoreva kuti dhigirii yekutsiviwa kweboka rimwe nerimwe paketani ye cellulose haina yunifomu yakakwana, uye ma microorganisms anogona kuparara pane isina kutsiva anhydroglucose boka kugadzira shuga , sekudya kunovaka tupukanana. Naizvozvo, kana dhigirii rekutsiva etherification ye cellulose richiwedzera, kuramba enzymatic erosion ye cellulose ether kuchawedzerawo. Maererano nemishumo, pasi pemamiriro ezvinhu akadzorwa, iyo hydrolysis mhedzisiro yema enzymes, iyo yakasara viscosity yehydroxypropyl methylcellulose (DS = 1.9) ndeye 13.2%, methylcellulose (DS = 1.83) ndeye 7.3%, methylcellulose (DS = 1.66) ndeye 3.8%. uye hydroxyethyl cellulose i1.7%. Zvinogona kuonekwa kuti hydroxypropyl methylcellulose ine simba rinopesana ne enzyme. Naizvozvo, iyo yakanakisa enzyme kuramba yehydroxypropyl methylcellulose, yakasanganiswa neiyo yakanaka dispersibility, thickening uye firimu-kugadzira zvinhu, inoshandiswa mumvura-emulsion coatings, nezvimwewo, uye kazhinji haidi kuwedzera zvinodzivirira. Zvisinei, nokuda kwekuchengetwa kwenguva refu kwechigadziro kana kusvibiswa kunobvira kubva kunze, zvinodzivirira zvinogona kuwedzerwa sechidziviriro, uye sarudzo inogona kugadziriswa maererano nezvinodiwa zvekupedzisira zvekugadzirisa. Phenylmercuric acetate uye manganese fluorosilicate zvinochengetedza zvinobudirira, asi zvese zvine Toxicity, kutarisisa kunofanirwa kubhadharwa kune oparesheni. Kazhinji, 1 ~ 5mg ye phenylmercury acetate inogona kuwedzerwa kune mhinduro parita yedhesi.
 
7. Kuita kwehydroxypropyl methylcellulose membrane
Kuita kwehydroxypropyl methylcellulose firimu Hydroxypropyl methylcellulose ine yakanakisa firimu-kugadzira zvimiro. Yayo aqueous solution kana organic solvent solution yakaputirwa pandiro yegirazi, uye inova isina ruvara uye yakajeka mushure mekuoma. Uye firimu rakaoma. Iine hunyoro hwakanaka hwekudzivisa uye inoramba yakasimba pakupisa kwepamusoro. Kana hygroscopic plasticizer yakawedzerwa, kureba kwayo uye kuchinjika kunogona kuvandudzwa. Panyaya yekuvandudza kushanduka, mapurasitiki akadai se glycerin uye sorbitol ndiyo inonyanya kukodzera. Kazhinji, kugadziriswa kwekugadzirisa ndeye 2% ~ 3%, uye huwandu hweplasticizer i10% ~ 20% ye cellulose ether. Kana zviri mukati meplasticizer zvakanyanyisa, colloidal dehydration shrinkage ichaitika pakunyorova kwepamusoro. Kusimba kwekusimba kwefirimu yakawedzerwa ne plasticizer yakakura kudarika iyo pasina kuwedzera, uye inowedzera nekuwedzera kwehuwandu hwekuwedzera, uye hygroscopicity yefirimu inowedzerawo nekuwedzera kwehuwandu hweplasticizer.


Nguva yekutumira: Zvita-19-2022
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