Focus on Cellulose ethers

Hydroxypropyl methylcellulose HPMC?

Hydroxypropyl methylcellulose HPMC waa unug aan-ionic cellulose isku qasan oo ka mid ah ethers kala duwan oo isku qasan oo leh ionic methylcarboxymethylcellulose. Kuma falceliso biraha culus. Farqiga u dhexeeya waxa ku jira hydroxypropyl methylcellulose, hydroxypropyl methylcellulose, iyo hydroxypropyl saamiga ku jira iyo viscosity ee hidde-free ogsijiinta leeyihiin gebi ahaanba kala duwan oo kala duwan xagga waxqabadka. Tusaale ahaan, noocyada leh maadada methoxyl sare iyo ka kooban hydroxypropyl hooseeya waxay leeyihiin waxqabadyo kala duwan. U dhow methylcellulose iyo noocyo ka kooban methoxy hoose. Marka la barbardhigo noocyada leh maadada hydroxypropyl sare, waxqabadkeedu wuxuu ku dhow yahay kan hydroxypropyl methylcellulose ee la soo saaray. Si kastaba ha noqotee, in kasta oo kala duwanaansho kastaa ay ka kooban tahay kaliya qadar yar oo ah kooxda hydroxypropyl ama tiro yar oo ah kooxda methoxy, waxaa jira kala duwanaansho weyn oo ku milmay dareerayaasha organic ama heerkulka flocculation ee xalalka aqueous.

 

1. Solubility of hydroxypropyl methylcellulose

Solubility of hydroxypropyl methylcellulose ee biyaha Hydroxypropyl methylcellulose dhab ahaantii waa propylene oxide (methylhydroxypropyl giraanta) methylcellulose la beddelay, sidaas darteed weli waxay leedahay sifooyin la mid ah methylcellulose Waxay leedahay sifooyin la mid ah in lagu milmo biyo qabow laakiin aan ku milmin biyaha kulul. Si kastaba ha ahaatee, heerkulka gelling ee hydroxypropyl la beddelay ee biyaha kulul aad ayuu uga sarreeyaa kan methylcellulose. Tusaale ahaan, 2% hydroxypropyl methylcellulose xal aqueous ah oo ay ku jiraan methoxy group content DS=0.73 iyo hydroxypropyl group MS=0.46 waxa ay leeyihin 500mpa 20°C. Heerkulka jel ee badeecada S wuxuu ku dhow yahay 100 ° C, halka kan methylcellulose ee isla heerkulka uu yahay kaliya 55°C. Marka laga hadlayo milanka biyaha, sidoo kale si weyn ayaa loo hagaajiyay. Tusaale ahaan, ka dib markii hydroxypropyl methylcellulose la burburiyo (qaabka qayb waa 0.2 ~ 0.5mm, viscosity ee 4% biyaha at 20 ° C waa 2pA·S, waxaa loo isticmaali karaa heerkulka qolka iyada oo aan qaboojin. Si fudud u milmi biyaha).

 

(2) Kala-noolaanshaha hydroxypropyl methylcellulose ee dareerayaasha dabiiciga ah milanka hydroxypropyl methylcellulose ee dareerayaasha organic ayaa sidoo kale ka fiican kan methylcellulose. Methylcellulose waxay u baahan tahay shahaadada beddelka methoxy ee 2.1 Alaabooyinka kor ku xusan waxay ka kooban yihiin viscosity hydroxypropyl methylcellulose oo leh hydroxypropyl MS=1.5 ~ 1.8 iyo methoxy DS=0.2 ~ 1.0, oo leh wadarta heerka beddelka ee in ka badan 1.8, waxayna si fudud ugu milmi karaan methan anhydrous ah. xal ethanol. Thermoplastic iyo biyo-milmay. Waxa kale oo ay ku milmi kartaa hydrocarbons koloriin leh sida methylene chloride iyo chloroform, iyo dareerayaasha organic sida acetone, khamriga isopropyl iyo aalkolada diacetone. Ku milmaynteeda dareerayaasha organic waxay ka fiican tahay milanka biyaha.

 

2. Waxyaabaha saameeya viscosity hydroxypropyl methylcellulose

Hydroxypropyl methylcellulose viscosity factor Qiyaasta viscosity caadiga ah ee hydroxypropyl methylcellulose waa la mid ah ethers kale cellulose, oo waxaa lagu qiyaasaa 20 ° C leh 2% aqueous xal sida caadiga ah. Viscosity ee isla badeecada ayaa kordha marka diirada la saaro. Alaabooyinka leh isku-fiirsasho isku mid ah iyo miisaanyo unugyo kala duwan, badeecada leh miisaan kelliyeedka weyn waxay leedahay viscosity sare. Xidhiidhka ay la leedahay heerkulka ayaa la mid ah kan methylcellulose. 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. Alaabooyinka viscosity hoose waxay leeyihiin heerkul gelling sare marka loo eego alaabta viscosity sare. Dhibcaha gelku maaha oo kaliya inay la xiriiraan viscosity ee etherka, laakiin sidoo kale waxay la xiriirtaa saamiga ka kooban methoxy iyo kooxaha hydroxypropyl ee etherka iyo wadarta guud ee beddelka. Waa in la ogaadaa in hydroxypropyl methylcellulose sidoo kale waa pseudoplastic; xalalkeedu waa xasiloon yihiin marka lagu kaydiyo heerkulka qolka mana muujiyaan wax dhimis ah viscosity, marka laga reebo xaalufka enzymatic ee suurtogalka ah.

 

3. Hydroxypropyl methylcellulose waa u adkaysta acid iyo alkali

Hydroxypropyl methylcellulose waa acid iyo alkali u adkaysta. Hydroxypropyl methyl cellulose waa u adkaysta acid iyo alkali. Guud ahaan way xasilloon tahay oo ma saamayn doonto qiimaha pH ee inta u dhaxaysa PH2 ~ 12. Waxay u adkeysan kartaa xaddi asiidh daciif ah, sida formic acid, acetic acid, iyo liin. Acid, succinic acid, phosphoric acid laakiin aashitada xoogga leh waxay leedahay saamaynta yaraynta viscosity. Alkali sida soodhaha caustic, potassium caustic, iyo biyaha lime wax saameyn ah kuma laha, laakiin saameynta wax yar kordhinta viscosity ee xalka ayaa si tartiib tartiib ah u yaraan doona hadhow.

 

4. Hydroxypropyl methylcellulose waa la isku dari karaa

Xalka Hydroxypropyl methylcellulose waxaa lagu qasi karaa xeryahooda polymer-ka biyaha-milmi kara si loo sameeyo labis iyo xal 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 xanjada qudhaca, xanjo digirta ayaxa, xanjo ayax, iwm. ayaa iyaguna leh isku dhafka wanaagsan. xalkeeda. Hydroxypropyl methylcellulose sidoo kale waxaa lagu qasi karaa stearic acid ama mannitol palmitate ama sorbitol, waxaana sidoo kale lagu qasi karaa glycerin, sorbitol iyo mannitol. Xeryahooda waxaa loo isticmaali karaa sida wakiilka balaastikada hydroxypropyl methylcellulose.

 

5. Hydroxypropyl methylcellulose waa mid aan lagu milmi karin biyaha

Hydroxypropyl methylcellulose waa mid aan milmi karin ethers-ka cellulose-ka ee biyaha-milmi kara waxayna noqon kartaa iskutallaabta dusha sare leh aldehyde, taas oo keenaysa ethers-biyoodka-milmay si ay u soo daadiso xalka oo ay noqdaan kuwo aan milmi karin biyaha. Oo samee hydroxypropyl methylcellulose mid aan milmayn aldehydes, formaldehyde, glioxal, succinic acid, dialdehyde, iwm. Markaad isticmaalayso formaldehyde, fiiro gaar ah waa in la bixiyaa qiimaha pH ee xalka. Waxaa ka mid ah, glioxal si dhakhso ah ayey uga falcelisaa, sidaa darteed waxaa loo isticmaalaa warshadaha Glyoxal waxaa badanaa loo isticmaalaa sidii wakiilka isku-xidhka ah ee wax soo saarka. -Wakiilka isku xirka. Qiyaasta wakiilka noocan oo kale ah ee isku dhafka ah ee xalka waa 0.2% ilaa 10% miisaanka ether, iyo ugu fiican waa 7% ilaa 10%. Haddii glycoxal la isticmaalo, 3.3% ilaa 6% ayaa 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, aashitada xoogga leh ee aan organic ama karboksylic acid organic ayaa lagu daraa xalka si loo hagaajiyo pH ee xalka ilaa 2 ilaa 6, oo la doorbidayo inta u dhaxaysa 4 iyo 6, ka dibna aldehydes ayaa lagu daraa si loo sameeyo falcelinta isku-xiran. Asiidhyada la isticmaalo waxaa ka mid ah hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, glycolic acid, succinic acid ama citric acid, kuwaas oo ay ka mid yihiin formic acid ama acetic acid ayaa ugu fiican, iyo formic acid ayaa ugu fiican. Acids iyo aldehydes ayaa sidoo kale lagu dari karaa isku mar si ay isku xiraan xalka gudaha qiyaasta pH ee la rabo. Dareen-celintan waxaa badanaa loo isticmaalaa tallaabada ugu dambeysa ee habka diyaarinta ether cellulose si loo sameeyo ether-ka cellulose aan la milmi karin oo loo fududeeyo dhaqidda iyo nadiifinta biyaha 20 ~ 25 ° C. Markaad isticmaalayso alaabta, waxaad ku dari kartaa walxaha alkaline ee xalka alaabta si aad u hagaajisid pH ee xalka si ay u noqoto alkaline si badeecadu si dhakhso ah ugu milmo xalka. Habkan waxa kale oo la isticmaali karaa marka filim la diyaariyo iyadoo la isticmaalayo xal ether cellulose ah ka dibna filimka waxaa lagu farsameeyaa filim aan la milmi karin.

 

6. Hydroxypropyl methylcellulose anti-enzyme

Soosaarayaasha cellulose ee hydroxypropyl methylcellulose ayaa aragti ahaan u adkaysta enzymes. Tusaale ahaan, koox kasta oo anhydroglucose ah waxay si adag ugu xidhan tahay koox beddela oo uma nuglaato nabaad-guurka microbial iyo caabuqa. Si kastaba ha ahaatee, dhab ahaantii, qiimaha beddelka ee alaabta la dhammeeyey ayaa ka sarreeya 1. Waxa kale oo lagu burburin karaa enzymes, taas oo muujinaysa in heerka beddelka koox kasta ee silsiladda cellulose ay tahay mid aan sinnayn, iyo microorganisms waxay baabi'in karaan kooxaha anhydroglucose aan la bedelin ee u dhow si ay u sameeyaan. Sonkorta, taas oo ay u nuugi karaan microorganisms cunto ahaan. Sidaa darteed, haddii heerka beddelka etherka ee cellulose uu kordho, iska caabinta ethers cellulose ee weerarka enzymatic ayaa kordhin doona. Waxaa lagu soo waramayaa in xaaladaha la kantaroolo, hydroxypropyl methylcellulose (DS=1.9), methylcellulose (DS=1.83), methylcellulose (DS=1.66), hydroxyethylcellulose (1.7%) Mawduucyada haraaga ah waa 13.2%, 7.3%, 3.8% iyo 1.7% siday u kala horreeyaan. Hydroxypropyl methylcellulose waxay leedahay awoodo anti-enzyme oo xoog leh. Waxaa la arki karaa in hydroxypropyl methylcellulose uu leeyahay iska caabin enzyme heer sare ah, oo ay weheliso kala firidhsan wanaagsan, dhumucdiisuna iyo sifooyinka filim-samaynta, waxaa loo isticmaali karaa in daahan emulsion, iwm, iyo guud ahaan uma baahna in lagu daro preservatives. Si kastaba ha noqotee, si looga hortago xalka kaydinta muddada-dheer ama wasakhowga dibadda ee suurtogalka ah, waxaa lagu dari karaa walxaha ilaaliya, xulashada ilaalinta ayaa lagu go'aamin karaa iyadoo lagu saleynayo shuruudaha ugu dambeeya ee xalka. Phenylmercuric acetate iyo manganese fluorosilicate waa ilaalin wax ku ool ah, laakiin waa sun waana in si taxadar leh loo maareeyaa. Guud ahaan, 1 ilaa 5 mg of phenylmercuric acetate ayaa lagu dari karaa litir kasta oo xal ah.

 

7. Waxqabadka xuubka hydroxypropyl methylcellulose

Guryaha sameynta filimada Hydroxypropyl methylcellulose Hydroxypropyl methylcellulose waxay leedahay sifooyin samaynta filim heer sare ah. Marka xalkeeda aqueous ama dareeraha dareeraha organic lagu dahaadhay saxan galaas, waxay noqotaa mid aan midab lahayn, hufan oo adag ka dib qalajinta. . Waxay leedahay iska caabin qoyaan oo wanaagsan waxayna ku sii adkaysataa heerkulka sare. Haddii balaastikada hygroscopic lagu daro, dhererka iyo dabacsanaanta ayaa la wanaajin karaa, dabacsanaantana waa la hagaajin karaa. Balaastigga sida glycerol iyo sorbitol ayaa ah kuwa ugu habboon. Xalka guud ee xalku waa 2% ~ 3%, iyo qiyaasta balaastikada waa 10% ~ 20% eter cellulose. Haddii maadada balaastikada looga baahan yahay inay sare u kacdo, kolloid syneresis wuxuu ku dhici doonaa qoyaan sare. Xoogga jilicsan ee filimka lagu daray balaastiigga ayaa aad uga weyn kan filimka aan lahayn balaastiig, wuxuuna kordhiyaa qadarka balaastiigga lagu daray. Hygroscopicity ee filimku sidoo kale wuxuu kordhiyaa qadarka balaastikada.


Waqtiga boostada: Febraayo-01-2024
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