Focus on Cellulose ethers

Hydroxypropyl Methyl Cellulose HPMC Properties

Hydroxypropyl methylcellulose HPMC waa nooc ka mid ah cellulose aan-ionic ahayn oo isku qasan. Si ka duwan ionic methyl carboxymethyl cellulose ether qasan, kuma falceliso biraha culus. Sababtoo ah saamiga kala duwan ee methoxyl content iyo hydroxypropyl content ee hydroxypropyl methylcellulose iyo viscosities kala duwan, waxaa jira noocyo badan oo kala duwan oo leh sifooyin kala duwan, tusaale ahaan, content methoxyl sare iyo content hydroxypropyl hoose Waxqabadkeedu wuxuu ku dhow yahay kan methyl cellulose, halka waxqabadka Maadada methoxy hoose iyo ka kooban hydroxypropyl sare waxay ku dhowdahay ta hydroxypropyl methyl cellulose. Si kastaba ha noqotee, nooc kasta, inkasta oo kaliya qadar yar oo ah kooxda hydroxypropyl ama qadar yar oo ah kooxda methoxyl ay ku jiraan, milanka dareeraha organic ama heerkulka flocculation ee xalka aqueous aad ayuu u kala duwan yahay.
 
1. milanka hydroxypropyl methylcellulose
①Solubility of hydroxypropyl methylcellulose biyaha Hydroxypropyl methylcellulose dhab ahaantii waa nooc ka mid ah methylcellulose modified by propylene oxide (methoxypropylene), sidaas darteed waxa ay weli leedahay sifooyin la mid ah sida methyl cellulose Cellulose waxa uu leeyahay sifooyin la mid ah milanka biyaha qabow iyo biyo kulul. 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 of hydroxypropyl methylcellulose xal aqueous leh 2% methoxy content beddelka degree DS=0.73 iyo hydroxypropyl content MS=0.46 waa wax soo saarka 500mpa?s at 20°C, iyo heerkulkeeda jel Waxa uu gaari karaa ku dhawaad ​​100° C, halka methyl cellulose isla heerkulka uu yahay kaliya 55 ° C. Sida ku milmideeda biyaha, sidoo kale si weyn ayaa loo hagaajiyay. Tusaale ahaan, methylcellulose hydroxypropyl-ka burburay (wax soo saarka leh cabbirka qayb ka mid ah 0.2 ~ 0.5mm iyo 4% viscosity xal aqueous of 2pa?s at 20 ° C waxaa laga iibsan karaa at heerkulka qolka, si fudud ayaa lagu milmi karaa biyaha iyada oo aan qaboojin. .
 
②Malka hydroxypropyl methylcellulose ee dareerayaasha organic. Alaabooyinka ka sarreeya 2.1,viscosity sare hydroxypropyl methylcelluloseka kooban hydroxypropyl MS=1.5 ~ 1.8 iyo methoxy DS=0.2 ~ 1.0, oo leh iskudarka beddelka ee ka sarreeya 1.8, waa ku milmay methanol anhydrous iyo xalalka ethanol Dhexdhexaad, iyo heerkulbeeg iyo biyo-milmi. Waxa kale oo ay ku milmi kartaa hydrocarbons koloriin leh sida methylene chloride iyo chloroform, iyo dareerayaasha organic sida acetone, isopropanol iyo diacetone khamriga. Ku milmaynteeda dareerayaasha organic waxay ka fiican tahay milanka biyaha.
 
2. Waxyaabaha saameeya viscosity hydroxypropyl methylcellulose
Waxyaabaha Saamayn ku leh Viscosity of Hydroxypropyl Methyl Cellulose Go'aaminta viscosity caadiga ah ee hydroxypropyl methyl cellulose waxay la mid tahay kuwa kale ethers cellulose. Waxa lagu qiyaasaa 20°C iyadoo la isticmaalayo 2% xal aqueous ah sida caadiga ah. Viscosity ee alaabta la mid ah waxay kordhisaa kororka feejignaanta. Alaabooyinka leh miisaan kala duwan oo unugyo isku mid ah, badeecada miisaankeedu weyn yahay waxay leedahay viscosity sare. Xidhiidhka ay la leedahay heerkulka ayaa la mid ah kan methyl cellulose. Marka heerkulku kor u kaco, viscosity-ku wuxuu bilaabmaa inuu hoos u dhaco, laakiin marka uu gaaro heerkul gaar ah, viscosity-ku si lama filaan ah ayuu u kacayaa waxaana soo baxa gelitaanka. Heerkulka jel ee alaabooyinka viscosity-yar ayaa sarreeya. waa sare. Its dhibic jel ma aha oo kaliya la xidhiidha viscosity of ether, laakiin sidoo kale la xidhiidha saamiga ka kooban ee kooxda metoxyl iyo kooxda hydroxypropyl ee ether iyo cabbirka wadarta shahaadada beddelka. Waa in la ogaadaa in hydroxypropyl methylcellulose sidoo kale waa pseudoplastic, iyo xalkeedu waa ku xasiloon yahay heerkulka qolka iyada oo aan wax nabaad-guur ah ee viscosity marka laga reebo suurtagalnimada hoos u enzymatic.
 
3. Hydroxypropyl methylcellulose waxay u adkaysataa acid iyo alkali
Hydroxypropyl methylcellulose acid iyo iska caabbinta alkali Hydroxypropyl methylcellulose guud ahaan waa mid degan asiidhka iyo alkaliska, mana saamayso inta u dhaxaysa pH 2 ~ 12. Waxay u adkeysan kartaa xaddi asiidh iftiin ah, Sida formic acid, acetic acid, citric acid, succinic acid, phosphoric acid, boric acid, iwm. Alkalis sida soodhaha caustic, potash caustic iyo biyaha lime wax saameyn ah kuma laha, laakiin waxay kordhin karaan viscosity ee xalka, ka dibna si tartiib ah u yareynaya.
 
4. Maqnaanshaha hydroxypropyl methylcellulose
Maqnaanshaha hydroxypropyl methylcellulose Hydroxypropyl methylcellulose xalka waxaa lagu qasi karaa xeryahooda polymer-ka biyaha-milmi kara si ay u noqdaan xal labis ah oo hufan oo leh viscosity sare. Xeryahooda polymer waxaa ka mid ah polyetylen glycol, polyvinyl acetate, polysilicon, polymethylvinylsiloxane, hydroxyethyl cellulose, iyo methyl cellulose. Iskudhisyada molecular sare ee dabiiciga ah sida cirridka carabiga, xanjada digirta ayaxa, xanjada karaya, iwm sidoo kale waxay leeyihiin waafaqid wanaagsan xalkeeda. Hydroxypropyl methylcellulose sidoo kale waxaa lagu qasi karaa mannitol ester ama sorbitol ester of stearic acid ama palmitic acid, sidoo kale waxaa lagu qasi karaa glycerin, sorbitol iyo mannitol, xeryahoodana waxaa loo isticmaali karaa sida hydroxypropyl methylcellulose Plasticizer for cellulose.
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5. Calool-la'aanta iyo milanka biyaha ee hydroxypropyl methylcellulose
Ether-yada cellulose-ka ee aan milmi karin ee hydroxypropyl methylcellulose waxa lagu xidhi karaa aldehydes oogada sare, sidaa darteed ether-yadan biyaha ku milmay waxay ku soo degdegaan xalka oo ay noqdaan kuwo aan milmi karin biyaha. Aldehydes ee ka dhigaya hydroxypropyl methylcellulose aan la karin karin waxaa ka mid ah formaldehyde, glyoxal, succinic aldehyde, adipaldehyde, iwm. Marka la isticmaalayo formaldehyde, fiiro gaar ah waa in la siiyaa qiimaha pH ee xalka, oo ka mid ah glioxal falcelin degdeg ah , sidaas darteed glioxal waxaa caadi ahaan loo isticmaalaa sida crosslink. wakiilka wax soo saarka warshadaha. Qadarka wakiilka noocan oo kale ah ee isku-dhafan ee xalka waa 0.2% ~ 10% miisaanka ether, doorbidaya 7% ~ 10%, tusaale ahaan, 3.3% ~ 6% glioxal ayaa ah kan ugu habboon. 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, xalka ayaa marka hore lagu daraa asiidh xooggan oo aan dabiici ahayn ama karboksylic acid organic si loo hagaajiyo pH ee xalka ilaa 2 ~ 6, oo doorbidan inta u dhaxaysa 4 ~ 6, ka dibna ku dar aldehydes si loo fuliyo falcelinta isku-xiran. Aashitada la isticmaalay ayaa leh hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxyacetic acid, succinic acid ama citric acid iwm. Aashitada iyo aldehyde ayaa sidoo kale lagu dari karaa isku mar si loogu oggolaado xalku inuu maro falcelin isku-dhafan oo dhexda ah 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 uu yahay mid aan la milmin, waxay ku habboon tahay in lagu dhaqo laguna nadiifiyo biyaha 20 ~ 25 ° C. Marka badeecada la isticmaalo, walxaha alkaline ayaa lagu dari karaa xalka badeecada 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 daaweynta filimka ka dib marka xalalka etherka cellulose laga sameeyo filim si looga dhigo filim aan la milmin.
 
6. Iska caabinta Enzyme ee hydroxypropyl methylcellulose
Iska caabbinta enzyme ee hydroxypropyl methylcellulose waa aragti ahaan derivatives cellulose, sida koox kasta oo anhydroglucose ah, haddii ay jiraan koox si adag isku xidhan, ma fududa in lagu qaadsiiyo microorganisms, laakiin dhab ahaantii alaabta la dhammeeyey Marka qiimaha beddelku ka badan yahay 1, waa. Waxa kale oo ay hoos u dhigi doonaa by ensaymes, taas oo macnaheedu yahay in heerka beddelka koox kasta on silsilad cellulose ma aha labis ku filan, iyo microorganisms lumin karaa on kooxda anhydroglucose aan la beddelin si ay u sameeyaan sonkor , sida nafaqooyinka for microorganisms si ay u nuugaan. Sidaa darteed, haddii heerka beddelka etherification ee cellulose uu kordho, iska caabinta enzymatic nabaad guurka etherka cellulose ayaa sidoo kale kordhin doona. Sida laga soo xigtay warbixinnada, xaaladaha la xakameeyey, natiijooyinka hydrolysis ee enzymes, haraaga haraaga ee hydroxypropyl methylcellulose (DS=1.9) waa 13.2%, methylcellulose (DS=1.83) waa 7.3%, methylcellulose (DS=1.66) waa 3.8%, iyo hydroxyethyl cellulose waa 1.7%. Waxaa la arki karaa in hydroxypropyl methylcellulose uu leeyahay awood xoog leh oo anti-enzyme ah. Sidaa darteed, iska caabbinta enzyme aad u fiican ee hydroxypropyl methylcellulose, oo ay weheliso kala-baxsanaanteeda wanaagsan, dhumucdeeda iyo sameynta filimada, ayaa loo isticmaalaa daaha-biyoodka-emulsion-ka, iwm, iyo guud ahaan uma baahna in lagu daro waxyaabaha ilaaliya. Si kastaba ha noqotee, kaydinta muddada dheer ee xalka ama wasakheynta suurtagalka ah ee ka imanaysa dibadda, 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 dhammaantood waxay leeyihiin sunta, dareenka waa in la bixiyaa hawlgalka. Guud ahaan, 1 ~ 5mg of phenylmercury acetate ayaa lagu dari karaa xalka halkii litir ee qiyaasta.
 
7. Waxqabadka xuubka hydroxypropyl methylcellulose
Waxqabadka filimka hydroxypropyl methylcellulose Hydroxypropyl methylcellulose wuxuu leeyahay sifooyin filim-samayn heer sare ah. Xalka aqueous ama dareeraha dareeraha organic waxa lagu dahaadhay saxan quraarad ah, oo waxay noqotaa mid aan midab lahayn oo daahfuran qalajinta ka dib. Iyo filim adag. Waxay leedahay iska caabin qoyaan oo wanaagsan waxayna ku sii adkaysataa heerkulka sare. Haddii balaastikada hygroscopic lagu daro, dhererkeeda iyo dabacsanaanteeda ayaa la wanaajin karaa. Marka la eego hagaajinta dabacsanaanta, balaastikada sida glycerin iyo sorbitol ayaa ah kuwa ugu habboon. Guud ahaan, xoojinta xalku waa 2% ~ 3%, iyo qadarka balaastiigga waa 10% ~ 20% eter cellulose. Haddii waxa ku jira balaastiiste aad u badan tahay, fuuqbaxa kolloidal waxay ku dhici doontaa qoyaan badan. Awoodda xajinta ee filimka lagu daray balaastik ayaa aad uga weyn tan iyada oo aan lagu darin, waxayna kordhisaa korodhka qadarka lagu daray, iyo hygroscopicity filimku sidoo kale wuxuu kordhiyaa korodhka qadarka balaastiigga.


Waqtiga boostada: Dec-19-2022
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