Focus on Cellulose ethers

Soo koobida guryaha HPMC ee hydroxypropyl methylcellulose

Hydroxypropyl methyl cellulose HPMC waa nooc ka mid ah cellulose aan ionic ahayn ether isku qasan, taas oo ka duwan ionic methyl carboxymethyl cellulose ether qasan, oo waxa aanu ka falcelin la biraha culus.Sababtoo ah saamiga kala duwan ee methoxyl content iyo hydroxypropyl content ee hydroxypropyl methylcellulose iyo viscosities kala duwan, waxay noqotay noocyo kala duwan oo kala duwan oo leh sifooyin kala duwan, tusaale ahaan, maadada methoxyl sare iyo content hydroxypropyl hooseeya Waxqabadkeedu wuxuu ku dhow yahay kan methyl cellulose, iyo Noocyada leh maadada methoxyl ee hooseeya iyo maadada hydroxypropyl sare, waxqabadkeedu wuxuu ku dhow yahay kan hydroxypropyl methylcellulose.Si kastaba ha noqotee, noocyo kala duwan, inkasta oo kaliya qadar yar oo ah kooxda hydroxypropyl ama qadar yar oo ah kooxda methoxy ay ku jiraan, milanka dareerayaasha organic ama heerkulka flocculation ee xalka aqueous aad ayey u kala duwan yihiin.

1. milanka hydroxypropyl methylcellulose

① milanka hydroxypropyl methyl cellulose ee biyahaCellulose waxay la mid tahay milanka biyaha qabow iyo biyo kulul oo aan milmayn.Si kastaba ha ahaatee, sababtoo ah kooxda hydroxypropyl ee la bedelay, heerkulka gelation ee biyaha kulul ayaa aad uga sarreeya kan methyl cellulose.Tusaale ahaan, viscosity ee xalka aqueous ee hydroxypropyl methylcellulose leh 2% methoxyl content DS=0.73 iyo hydroxypropyl content MS=0.46 waa 500mpa?s at 20°C.Heerkulkeeda jel waxa uu gaari karaa ku dhawaad ​​100°C, halka methylcellulose isla heerkulku uu yahay 55°C.Marka laga hadlayo milanka biyaha, sidoo kale si weyn ayaa loo hagaajiyay.Tusaale ahaan, hydroxypropyl methylcellulose oo la burburiyay (qaabka granular ee 0.2 ~ 0.5mm at 20 ° C leh viscosity of 4% xal aqueous ilaa 2pa?s waxaa loo isticmaali karaa heerkulka qolka, si fudud ayay ugu milmay biyaha iyada oo aan qaboojin.

②Malka hydroxypropyl methyl cellulose ee dareerayaasha organic. hydroxypropyl MS = 1.5 ~ 1.8 iyo methoxy DS = 0.2 ~ 1.0, iyo wadarta guud ee bedelka ee ka sarreeya 1.8 waxay ku milmeen methanol anhydrous iyo ethanol dhexdhexaad ah, heerkulbeeg iyo biyo-milmi leh.Waxa kale oo ay ku milmi kartaa hydrocarbons koloriin leh sida dichloromethane iyo chloroform, iyo dareerayaasha organic sida acetone, isopropanol iyo diacetone khamriga.Ku milmaynteeda dareerayaasha organic waxay ka fiican tahay kuwa biyaha lagu milmo.

2. Waxyaabaha saameeya viscosity hydroxypropyl methylcellulose

Waxyaabaha saamaynta leh ee viscosity hydroxypropyl methyl cellulose go'aaminta viscosity caadiga ah ee hydroxypropyl methyl cellulose, sida ethers kale ee cellulose, waxay ku salaysan tahay 2% xal aqueous ah 20 ° C.Viscosity ee alaabta la mid ah waxay kordhisaa korodhka feejignaanta.Alaabooyinka leh miisaan kala duwan oo unugyo isku mid ah, alaabada miisaankoodu weyn yahay waxay leeyihiin viscosity sare.Xidhiidhka ay la leedahay heerkulka ayaa la mid ah kan methyl cellulose.Marka heerkulku kordho, mawgu wuxuu bilaabmaa inuu hoos u dhaco, laakiin marka uu gaaro heerkul gaar ah, mawqifka ayaa si lama filaan ah u kordheysa oo jeexjeexa ayaa dhacaya.Heerkulka jel ee alaabooyinka viscosity-yar ayaa sarreeya.waa sareIts dhibic gel ma aha oo kaliya la xidhiidha viscosity ee ether ah, laakiin sidoo kale in ratio ka kooban methoxy iyo hydroxypropyl ee ether iyo heerka guud ee beddelka.Waa in la ogaadaa in hydroxypropyl methylcellulose uu sidoo kale yahay pseudoplastic oo xalkeedu uu ku xasilo heerkulka qolka iyada oo aan wax hoos u dhigin viscosity marka laga reebo suurtagalnimada hoos u dhaca enzymatic.

3. Hydroxypropyl methylcellulose acid iyo caabbinta alkali

Hydroxypropyl methylcellulose acid iyo caabbinta alkali Hydroxypropyl methylcellulose guud ahaan waa mid degan aashitada iyo alkali, mana saamayso inta u dhaxaysa pH 2 ~ 12.Waxay u adkeysan kartaa xaddi aashito fudud ah.Sida formic acid, acetic acid, citric acid, succinic acid, phosphoric acid, boric acid, iwm. Si kastaba ha ahaatee, aashitada xoogga leh ayaa saameyn ku leh hoos u dhigista viscosity.Alkali sida soodhaha caustic, potash caustic iyo biyaha lime wax saameyn ah kuma laha, laakiin waxay kordhin karaan viscosity ee xalka, ka dibna waxaa jiri doona ifafaale hoos u dhac tartiib ah mustaqbalka.

4. Isku-dhafka hydroxypropyl methylcellulose

Maqnaanshaha Hydroxypropyl Methyl Cellulose Xalka Hydroxypropyl methyl cellulose waxaa lagu qasi karaa iskudarka polymer-ka ee biyaha-milmi kara si ay u noqdaan xal isku mid ah oo hufan oo leh viscosity sare.Xeryahooda polymer waxaa ka mid ah polyetylen glycol, polyvinyl acetate, polysiloxane, polymethyl vinyl siloxane, hydroxyethyl cellulose iyo methyl cellulose.Iskudhisyada polymer-ka dabiiciga ah sida cirridka carabiga, xanjo ayax, xanjo karaya, iwm. sidoo kale waxay leeyihiin iskudhaf wanaagsan oo xalkeeda ah.Hydroxypropyl methylcellulose sidoo kale waxaa lagu qasi karaa mannitol ama sorbitol esters of stearic acid ama palmitic acid, waxaana sidoo kale lagu qasi karaa glycerin, sorbitol iyo mannitol.Xeryahooda waxaa loo isticmaali karaa sida hydroxypropyl methylcellulose.Plasticizer-ku-saleysan cellulose.

5. Biyo la'aanta iyo milanka biyaha ee hydroxypropyl methylcellulose

Ethers-ka cellulose-ka biyaha-milmi kara ee hydroxypropyl methylcellulose waxa lagu xidhi karaa dusha sare ee aldehyde, iyo eter-yada biyaha-milmi kara waxay ku soo dagdagaan xalka waxayna noqdaan kuwo aan milmi karin biyaha.Aldehydes-ka sameeya hydroxypropyl methylcellulose aan la milmi karin waxaa ka mid ah formaldehyde, glyoxal, succinaldehyde, adipaldehyde, iwm. Marka la isticmaalayo formaldehyde, fiiro gaar ah waa in la siiyaa qiimaha pH ee xalka, kuwaas oo glioxal uu si dhakhso ah u falceliyo.Sidaa darteed, glycoxal waxaa caadi ahaan loo isticmaalaa sidii wakiilka iskutallaabta ee wax soo saarka warshadaha.Qiyaasta nooc ka mid ah wakiilka isdhaafsiga ee xalka waa 0.2% ~ 10% cufka etherka, doorbidaya 7% ~ 10%, iyo 3.3% ~ 6% ayaa ah kan ugu habboon glioxal.Heerkulka daawaynta guud waa 0 ~ 30℃, waqtiguna waa 1 ~ 120min.Dareen-celinta isku-xiran waxay u baahan tahay in lagu sameeyo xaaladaha acidic.Guud ahaan, aashitada xoogga leh ee aan organic ama karboksylic acid organic ayaa lagu daraa xalka si loo hagaajiyo pH ee xalka ilaa 2 ~ 6, oo la doorbidayo inta u dhaxaysa 4 ~ 6, ka dibna aldehydes ayaa lagu daraa si loo fuliyo falcelinta isku-xiran..Asiidhyada la isticmaalo waxaa ka mid ah hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxyacetic acid, succinic acid ama citric acid, kuwaas oo ay ka mid yihiin formic acid ama acetic acid ay ku haboon tahay, iyo formic acid waa tan ugu fiican.Aashitada iyo aldehyde ayaa sidoo kale lagu dari karaa isku mar si loogu oggolaado in xalku isku xiro qiyaasta pH ee la rabo.Dareen-celintan waxaa badanaa loo isticmaalaa habka daaweynta ugu dambeysa ee habka diyaarinta ethers cellulose.Ka dib markii ether-ka cellulose-ka aan la xalin, waxay ku habboon tahay in lagu dhaqo oo lagu nadiifiyo biyaha 20 ~ 25 ° C.Marka badeecada la isticmaalo, walaxda alkaline ayaa lagu dari karaa xalka alaabta si loo hagaajiyo pH ee xalka si ay u noqoto alkaline, badeecaduna waxay ku milmi doontaa xalka si dhakhso ah.Habkani wuxuu sidoo kale lagu dabaqi karaa xalalka etherka cellulose ee laga sameeyay filim ka dibna filimka ayaa la farsameeyaa si looga dhigo filim aan la milmin.

6. Hydroxypropyl methylcellulose waxay u adkaysataa enzymes

Hydroxypropyl methylcellulose waxay u adkaysataa enzymes.Aragti ahaan, derivatives cellulose, sida koox kasta oo anhydroglucose, waxay leeyihiin koox si adag isku xidhan, taas oo aan fududayn in ay qaadaan jeermiska, laakiin dhab ahaantii alaabta la dhammeeyey Marka qiimaha beddelka ka badan 1, waxa ay sidoo kale hoos u dhigi doonaa by enzymes. taas oo macnaheedu yahay in heerka beddelka koox kasta ee silsiladda cellulose aysan ahayn mid isku mid ah oo ku filan, iyo microorganisms waxay baabi'in karaan meel u dhow kooxaha anhydroglucose aan la bedelin si ay u sameeyaan sonkor., kuwaas oo la nuugo sida nafaqeynta noolaha.Sidaa darteed, haddii heerka beddelka etherification ee cellulose uu kordho, iska caabinta nabaad-guurka enzymatic ee etherka cellulose sidoo kale waa la xoojiyaa.Waxaa la sheegay in viscosity haraaga hydroxypropyl methylcellulose (DS=1.9) waa 13.2%, methylcellulose (DS=1.83) waa 7.3%, iyo methylcellulose (DS=1.66) waa 3.8%, iyo hydroxyethyl cellulose waa 1.7%.Waxaa la arki karaa in awoodda anti-enzyme ee hydroxypropyl methylcellulose ay tahay mid xooggan.Sidaa darteed, iska caabbinta enzym ee aadka u fiican ee hydroxypropyl methylcellulose, oo ay weheliso kala-baxsanaanteeda wanaagsan, dhumucdeeda iyo sameynta filimada, ayaa guud ahaan loo isticmaalaa daaha-biyoodka-emulsion-ka, iwm, guud ahaanna uma baahna in lagu daro waxyaabaha ilaaliya.Si kastaba ha noqotee, kaydinta muddada dheer ee xalka ama wasakhowga suurtagalka ah ee adduunka ka baxsan, ilaalinta ayaa lagu dari karaa taxadar ahaan, doorashadana waxaa lagu go'aamin karaa iyadoo loo eegayo shuruudaha ugu dambeeya ee xalka.Phenylmercuric acetate iyo manganese fluorosilicate waa ilaalin wax ku ool ah, laakiin waxay leeyihiin labadaba sunta, dareenka waa in la bixiyaa qaliinka, qiyaasta guud ahaan waa 1 ~ 5mg of phenylmercuric acetate halkii litir oo xal ah.

7. Tilmaamaha filimka hydroxypropyl methylcellulose

Waxqabadka filimka hydroxypropyl methylcellulose Hydroxypropyl methylcellulose wuxuu leeyahay sifooyin filim samaynta heer sare ah, iyo xalkeeda aqueous ama dareeraha dareeraha organic waxaa lagu dahaadhay saxan galaas, oo waxay noqotaa mid aan midab lahayn oo hufan ka dib qallajinta.Iyo filim adag.Waxay leedahay iska caabin qoyaan oo wanaagsan waxayna ku sii adkaysataa heerkulka sare.Tusaale ahaan, ku darida balaastikada hygroscopic waxay kor u qaadi kartaa dhererkeeda iyo dabacsanaanteeda.Si loo hagaajiyo dabacsanaanta, balaastikada sida glycerin iyo sorbitol ayaa ah kuwa ugu habboon.Xalka guud ee xalku waa 2% ~ 3%, iyo qadarka balaastiigga waa 10% ~ 20% ether cellulose.Haddii waxa ku jira balaastikada ay aad u sarreyso, ifafaalaha yaraanta ee fuuqbaxa kolloid waxay ku dhici doontaa qoyaan sare.Xoogga jilicsan ee filimka lagu daray balaastiigga ayaa aad uga weyn kan aan lahayn balaastiig, waxayna kordhisaa korodhka qadarka lagu daray.Sida hygroscopicity ee filimka, waxay sidoo kale kordhisaa kordhinta qadarka balaastikada.


Waqtiga boostada: Oct-13-2022
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