Daraasad ku saabsan Xakamaynta Tayada Hydroxypropyl Methyl Cellulose

Marka loo eego xaaladda hadda jirta ee wax soo saarka HPMC ee dalkayga, arrimaha saameeya tayada hydroxypropyl methylcellulose ayaa la falanqeeyay, iyadoo taas ku saleysan, sida loo hagaajiyo heerka tayada hydroxypropyl methylcellulose ayaa laga wada hadlay oo la darsay, si loo soo saaro.

Erayada muhiimka ah:hydroxypropyl methylcellulose; tayada; xakamaynta; cilmi baaris

Hydroxypropyl methylcellulose (HPMC) waa cellulose aan-ionic-biyo ku milmi karin oo isku qasan oo laga sameeyay suuf, alwaax, iyo etherified propylene oxide iyo methyl chloride ka dib bararka alkali. Ether-ka isku-dhafan ee Cellulose waa Eter-ka la beddelay ee etherka beddelka ah wuxuu leeyahay sifooyin gaar ah oo ka wanaagsan monoether-ka asalka ah, wuxuuna u ciyaari karaa waxqabadka etherka cellulose si dhammaystiran oo qumman. Waxaa ka mid ah ethers badan oo isku dhafan, hydroxypropyl methylcellulose waa tan ugu muhiimsan. Habka diyaarinta waa in lagu daro propylene oxide in cellulose alkaline. Warshadaha HPMC waxa lagu tilmaami karaa badeecad caalami ah. Heerka beddelka kooxda methyl (qiimaha DS) waa 1.3 ilaa 2.2, iyo heerka beddelka molar ee hydroxypropyl waa 0.1 ilaa 0.8. Waxaa laga arki karaa xogta kor ku xusan in content iyo sifooyinka methyl iyo hydroxypropyl ee HPMC ay kala duwan yihiin, taasoo keentay in viscosity wax soo saarka ugu dambeeya iyo Farqiga in lebbiska keenaysaa in isbedel tayada alaabta la dhammeeyey ee shirkadaha wax soo saarka kala duwan.

Hydroxypropyl methylcellulose waxay soo saartaa ether derivatives iyada oo loo marayo falcelin kiimikaad, kuwaas oo isbeddel qoto dheer ku leh halabuurka, qaab-dhismeedka iyo hantida, gaar ahaan milanka cellulose, taas oo lagu kala duwanaan karo nooca iyo qadarka kooxaha alkyl ee la soo bandhigay. Soo hel derivatives ether-ku milmay biyaha, xalalka alkali milo, dareerayaasha polar (sida ethanol, propanol) iyo dareerayaasha organic non-polar (sida benzene, ether), kaas oo si weyn u balaadhiya noocyada iyo beeraha codsiga ee derivatives cellulose.

1. Saamaynta habka alkalization hydroxypropyl methylcellulose ee tayada

Habka alkalization waa tallaabada ugu horreysa ee heerka falcelinta ee wax soo saarka HPMC, iyo sidoo kale waa mid ka mid ah tallaabooyinka ugu muhiimsan. Tayada dabiiciga ah ee alaabta HPMC waxaa inta badan go'aamiya habka alkalization, ma aha habka etherification, sababtoo ah saameynta alkalization waxay si toos ah u saameyneysaa saameynta etherification.

Hydroxypropyl methylcellulose wuxuu la falgalaa xalalka alkaline si uu u sameeyo alkali cellulose, kaas oo aad u firfircoon. Dareen-celinta etherification, fal-celinta ugu weyn ee wakiilka etherification ee bararka, dhexgalka, iyo etherification ee cellulose iyo Heerka falcelinta dhinaca, isku midka ah ee falcelinta iyo sifooyinka alaabta kama dambaysta ah ayaa dhammaantood la xiriira sameynta iyo halabuurka cellulose alkali, sidaas darteed qaab-dhismeedka iyo sifooyinka kiimikada ee cellulose alkali waa shay cilmi-baaris oo muhiim ah in wax soo saarka ether cellulose.

2. Saamaynta heerkulka tayada hydroxypropyl methylcellulose

Qayb gaar ah oo ah xalka aqueous KOH, qadarka adsorption iyo heerka bararka ee hydroxypropyl methylcellulose ilaa alkali waxay kordhisaa hoos u dhaca heerkulka falcelinta. Tusaale ahaan, wax soo saarka alkali cellulose way kala duwan tahay iyadoo la eegayo xoojinta KOH: 15%, 8% at 10°C, iyo 4.2% at 5°C. Habka isbeddelkan ayaa ah in samaynta cellulose alkali ay tahay habka falcelinta exothermic. Marka heerkulku kor u kaco, xayeysiinta hydroxypropyl methylcellulose on alkali Qadarka ayaa hoos u dhacaya, laakiin falcelinta hydrolysis ee cellulose alkali ayaa si weyn u kordhay, taas oo aan ku habboonayn samaynta alkali cellulose. Waxaa laga arki karaa kor ku xusan in hoos u dhigista heerkulka alkalization ay ku haboon tahay jiilka alkali cellulose waxayna joojisaa falcelinta hydrolysis.

3. Saamaynta waxyaabaha lagu daro tayada hydroxypropyl methylcellulose

In nidaamka cellulose-KOH-biyaha, lagu daro-milixdu waxay saameyn weyn ku leedahay sameynta alkali cellulose. Marka xoojinta xalka KOH uu ka hooseeyo 13%, xayeysiinta cellulose ee alkali ma saameynayso ku darida cusbada chloride potassium. Marka fiirsashada dareeraha lye uu ka sarreeyo 13%, ka dib marka lagu daro potassium chloride, xayaysiinta muuqata ee cellulose ilaa alkali Xayeysiintu waxay kordhisaa xoojinta chloride potassium, laakiin wadarta awoodda xayeysiinta ayaa hoos u dhacda, xayeysiinta biyuhuna aad ayay u kordheysaa, sidaas darteed ku darida milixdu guud ahaan uma fiicna alkalization iyo bararka cellulose, laakiin milixdu waxay joojin kartaa hydrolysis waxayna nidaamin kartaa nidaamka Mawduuca biyaha bilaashka ah sidaas darteed waxay hagaajinaysaa saameynta alkalization iyo etherification.

4. Saamaynta habka wax soo saarka ee tayada hydroxypropyl methylcellulose

Waqtigan xaadirka ah, shirkadaha wax soo saarka hydroxypropyl methylcellulose ee dalkaygu waxay inta badan qaataan habka wax soo saarka ee habka dareeraha. Habka diyaarinta iyo etherification ee cellulose alkali waxaa dhamaantood lagu fuliyaa dareere organic aan firfircoonayn, sidaas darteed suufka la safeeyey alaabta ceeriin loo baahan yahay in la miiray si loo helo aag weyn oo dusha sare iyo falcelinta si loo hubiyo tayada alaabta la dhammeeyey.

Ku dar cellulose-ka burburay, dareeraha organic iyo xalalka alkali galay reactor, oo isticmaal walaaqaya farsamaysan oo awood leh heerkul iyo wakhti gaar ah si aad u hesho cellulose alkali leh alkalization uniform iyo hoos u dhac yar. dareerayaasha dareeraha ah ee dabiiciga ah (isopropanol, toluene, iwm.) waxay leeyihiin dareen-xumo gaar ah, taas oo ka dhigaysa hydroxypropyl methylcellulose sii daaya kulayl isku mid ah inta lagu jiro habka formation, muujinaya horumarka sii daayo tallaabo tallaabo ah, iyadoo la dhimayo falcelinta hydrolysis of cellulose alkali jihada ka soo horjeeda Si aad u hesho sare- cellulose alkali oo tayo leh, sida caadiga ah fiirsashada lye ee loo isticmaalo isku xirkani waa ilaa 50%.

Ka dib markii cellulose lagu qooyay lye, si buuxda u barara oo siman alkali cellulose ayaa la helay. Lye osmotically si fiican ayey u barari kartaa cellulose, iyada oo aasaas wanaagsan u ah falcelinta etherification ee xiga. Dheecaannada caadiga ah inta badan waxaa ka mid ah isopropanol, acetone, toluene, iwm. milanka lye, nooca dareeraha iyo xaaladaha walaaqaya ayaa ah arrimaha ugu muhiimsan ee saameeya halabuurka alkali cellulose. Lakabyada sare iyo kuwa hoose ayaa la sameeyaa marka la isku daro. Lakabka sare wuxuu ka kooban yahay isopropanol iyo biyo, lakabka hoosena wuxuu ka kooban yahay alkali iyo qadar yar oo isopropanol ah. Cellulose-ka ku kala firirsan nidaamka ayaa si buuxda ula xiriiray lakabyada dareeraha ee sare iyo hoose ee hoos yimaada mashiinka. Alkaliyada ku jira nidaamka Isku-dheelitirnaanta biyuhu way isbedeshaa ilaa cellulose la sameeyo.

Sida cellulose caadiga ah ether isku qasan non-ionic, content ee kooxaha hydroxypropyl methylcellulose waa on silsilado macromolecular kala duwan, taas oo ah, saamiga qaybinta methyl iyo hydroxypropyl kooxaha waa ka duwan on C ee booska giraanta gulukoos kasta. Waxay leedahay kala firir weyn iyo randomity, taas oo adkeyneysa in la dammaanad qaado xasilloonida tayada badeecada.