Hydroxypropyl methylcellulose (HPMC) waa unug muhiim ah oo unug-synthetic cellulose ah, kaas oo si weyn loogu isticmaalo daawada, qalabka dhismaha, cuntada, daahan iyo warshadaha kale. HPMC waxay leedahay dhumuc wanaagsan, emulsification, filim samaynta, qoyaanka, xasilinta iyo guryaha kale, sidaa darteed waxay leedahay qiimo codsi oo muhiim ah dhinacyo badan. Alaabta ceeriin ee ugu muhiimsan ee soo saarista HPMC waxaa ka mid ah cellulose, sodium hydroxide, propylene oxide, methyl chloride iyo biyo.
1. Cellulose
Cellulose waa sheyga ugu muhiimsan ee aasaasiga ah ee HPMC, oo inta badan laga helo fiilooyinka dhirta dabiiciga ah sida suufka iyo alwaax. Cellulose waa polymer-ka dabiiciga ah ee ugu badan ee dhulka. Qaab dhismeedkeeda kelli waa polysaccharide silsilad dheer oo ka kooban unugyo gulukoos oo ku xiran β-1,4-glycosidic bonds. Cellulose lafteedu kuma milmi karaan biyaha mana laha falcelin kiimiko oo wanaagsan. Sidaa darteed, taxane ah hababka wax ka beddelka kiimikaad ayaa loo baahan yahay si kor loogu qaado milmaheeda iyo shaqeynteeda si loo diyaariyo alaabada ether-ka cellulose ee kala duwan.
2. Sodium hydroxide (NaOH)
Sodium hydroxide, oo sidoo kale loo yaqaano soodhaha caustic, waa xarun alkaliin adag ah oo door muhiim ah ka ciyaara sida alkalizer habka wax soo saarka ee HPMC. Marxaladda hore ee wax soo saarka, cellulose waxay la falgashaa xalalka sodium hydroxide si ay u dhaqaajiso kooxaha hydroxyl ee silsiladda molecular cellulose, taas oo bixisa goobaha falcelinta ee falcelinta etherification ee xiga. Tallaabadan waxa kale oo loo yaqaan "falcelinta alkalization". cellulose-ka alkalized waxa uu maraa isbedelo qaab dhismeed gaar ah, taas oo sahlaysa in lagaga falceliyo reagen kiimikaad ee danbe (sida propylene oxide iyo methyl chloride).
3. Propylene oxide (C3H6O)
Propylene oxide waa mid ka mid ah walxaha muhiimka ah ee wax soo saarka HPMC, inta badan loo isticmaalo in kooxaha hydroxyl ee cellulose loogu beddelo kooxaha hydroxypropyl. Gaar ahaan, cellulose-ka alkalized wuxuu la falgalaa propylene oxide hoostiisa heerkulka qaarkood iyo xaaladaha cadaadiska, iyo kooxaha epoxy firfircoon ee propylene oxide waxay ku xiran yihiin silsiladda molecular ee cellulose iyada oo loo marayo falcelinta dheeriga ah ee furitaanka si ay u sameeyaan beddelka hydroxypropyl. Habkani wuxuu siinayaa HPMC biyo wanaagsan oo milmay iyo awood dhumuc leh.
4. Methyl chloride (CH3Cl)
Methyl chloride waa wakiilka kale ee muhiimka ah ee loo isticmaalo in lagu beddelo kooxaha hydroxyl ee cellulose kooxo methoxyl ah. Methyl chloride waxay la falgashaa kooxaha hydroxyl ee silsiladda molecular cellulose iyada oo loo marayo falcelinta beddelka nucleophilic si loo soo saaro methyl cellulose. Iyada oo loo marayo falcelinta methylation-ka, HPMC waxay helaysaa hydrophobicity wanaagsan, gaar ahaan muujinta milmayn heer sare ah ee dareerayaasha organic qaarkood. Intaa waxaa dheer, soo bandhigida kooxaha methoxy waxay sii wanaajisaa hantida sameynta filimada iyo xasilloonida kiimikada ee HPMC.
5. Biyaha
Biyaha, sida dareeraha iyo falcelinta dhexdhexaadka ah, waxay dhex maraan dhammaan habka wax soo saarka HPMC. Dareen-celinta alkalization iyo etherification, biyuhu ma aha oo kaliya inay caawiyaan inay milmaan sodium hydroxide oo ay hagaajiyaan xaaladda fuuq-celinta ee cellulose, laakiin sidoo kale waxay ka qaybqaataan nidaaminta kulaylka falcelinta si loo hubiyo xakamaynta heerkulka inta lagu jiro habka falcelinta. Nadiifnimada biyuhu waxay saameyn muhiim ah ku leedahay tayada HPMC, iyo biyo nadiif ah oo nadiif ah ama biyo nadiif ah ayaa badanaa loo baahan yahay.
6. dareerayaasha dabiiciga ah
Habka wax soo saarka ee HPMC, tallaabooyinka habraaca qaarkood ayaa sidoo kale u baahan kara isticmaalka qaar ka mid ah dareerayaasha organic, sida methanol ama ethanol. Walxahaan waxaa mararka qaarkood loo isticmaalaa in lagu hagaajiyo viscosity ee habka falcelinta, la dhimo samaynta falcelinta by-products, ama kor loogu qaado falcelin kiimikaad gaar ah. Doorashada dareeraha organic waxay u baahan tahay in la go'aamiyo iyadoo loo eegayo baahida habka wax soo saarka iyo codsiga alaabta ugu dambeysa.
7. Qalab kale oo caawimo ah
Marka lagu daro alaabta ceeriin ee sare ee kor ku xusan, habka wax-soo-saarka dhabta ah, qaar ka mid ah qalabka wax-qabadka iyo waxyaabaha lagu daro, sida kicinta, xasiliyeyaasha, iwm, ayaa loo isticmaali karaa si loo hagaajiyo waxtarka falcelinta, la xakameeyo heerka falcelinta ama hagaajinta sifooyinka jirka iyo kiimikada. ee alaabta kama dambaysta ah.
8. Tallaabooyinka ugu muhiimsan ee habka wax soo saarka
Tillaabooyinka habka ugu muhiimsan ee soo saarista HPMC waxaa loo qaybin karaa saddex qaybood: alkalization, etherification iyo daawaynta dhexdhexaadinta. Marka hore, cellulose waxay la falgashaa sodium hydroxide si ay alkalize u sameyso si ay u sameyso alkali cellulose. Kadibna, etherification waxay ku dhacdaa falcelinta alkali cellulose leh propylene oxide iyo methyl chloride si ay u sameeyaan hydroxypropyl iyo methoxy beddelka ethers cellulose. Ugu dambeyntii, iyada oo loo marayo daaweynta dhexdhexaadinta, dhaqidda, qalajinta iyo hababka kale, alaabta HPMC oo leh milmo gaar ah, viscosity iyo sifooyin kale ayaa la helay.
9. Saamaynta tayada alaabta ceeriin ee waxqabadka alaabta HPMC
Ilaha kala duwan ee alaabta ceeriin iyo nadiifnimada ayaa saameyn weyn ku leh tayada iyo waxqabadka HPMC ee u dambeeya. Tusaale ahaan, nadiifinta iyo qaybinta miisaanka kelli ee alaabta ceeriin ee cellulose waxay saameyn doontaa viscosity iyo milanka HPMC; qiyaasta iyo xaaladaha falcelinta propylene oxide iyo methyl chloride ayaa go'aamin doona heerka hydroxypropyl iyo beddelka methoxy, sidaas darteed saameynaya saamaynta dhumuc iyo sifooyinka filim-samaynta alaabta. Sidaa darteed, xulashada iyo xakamaynta tayada alaabta ceeriin ayaa muhiim ah inta lagu jiro habka wax soo saarka.
Qalabka ugu muhiimsan ee hydroxypropyl methylcellulose (HPMC) waxaa ka mid ah cellulose, sodium hydroxide, propylene oxide, methyl chloride iyo biyo. Iyada oo loo marayo taxane falcelin kiimiko ah oo adag, alaabtan ceeriin ayaa loo beddelaa wax shaqaynaya oo leh qiime ballaadhan. Codsiga kala duwan ee HPMC wuxuu daboolayaa qaybo badan sida daawada, qalabka dhismaha, iyo cuntada. Sifooyinkiisa wanaagsan ee jirka iyo kiimikaad ayaa ka dhigaya mid aan looga maarmin warshado badan.
Waqtiga boostada: Sebtembar-30-2024