IHydroxypropyl methylcellulose (HPMC) yipolymer eyenziweyo evela kwiselulosi kwaye iqhele ukusetyenziswa njenge-thickener, emulsifier, kunye ne-stabilizer kumashishini ahlukeneyo afana nokutya, amayeza, kunye nezinto zokuthambisa. I-HMPC yi-hydroxypropylated derivative ye-methylcellulose (MC), i-ether ye-cellulose ye-nonionic e-soluble yamanzi eyenziwe ngeeyunithi ze-cellulose ze-methoxylated kunye ne-hydroxypropylated. I-HMPC isetyenziswa ngokubanzi njenge-excipient kwimixube yamayeza ngenxa yokungabi natyhefu, ukuhambelana kwezinto eziphilayo, kunye nokubola kwayo.
Iimpawu zeekhemikhali ze-HMPC:
Iimpawu zeekhemikhali ze-HMPC zibangelwa ubukho be-hydroxyl kunye namaqela e-ether kwisakhiwo sayo se-molecular. Amaqela e-hydroxyl ye-cellulose anokusebenza ngokuphendula kweekhemikhali ezahlukeneyo, ezifana ne-etherification, i-esterification, kunye ne-oxidation, ukwazisa amaqela ahlukeneyo asebenzayo kwi-polymer backbone. I-HMPC iqulethe zombini i-methoxy (-OCH3) kunye ne-hydroxypropyl (-OCH2CHOHCH3) amaqela, anokulawulwa ukubonelela ngeempawu ezahlukeneyo ezifana ne-solubility, viscosity kunye ne-gelation.
I-HMPC inyibilika kakhulu emanzini, yenze izisombululo ezicacileyo, ezibonayo kwiindawo eziphantsi. I-viscosity yezisombululo ze-HMPC zinokutshintshwa ngokulungelelanisa iqondo lokutshintshwa (i-DS) yamaqela e-hydroxypropyl, emisela inani leendawo ze-hydroxyl eziguqulwayo kwiyunithi ye-glucose. Iphezulu i-DS, i-solubility ephantsi kwaye iphezulu i-viscosity yesisombululo se-HMPC. Le propati ingasetyenziselwa ukulawula ukukhutshwa kwezithako ezisebenzayo kwiifomyula zamachiza.
I-HMPC ikwabonisa ukuziphatha kwepseudoplastic, okuthetha ukuba i-viscosity iyancipha ngokunyuka kwesantya sokucheba. Le propati yenza ukuba ifaneleke njenge-thickener yokwenziwa kolwelo olufuna ukumelana nemikhosi yokucheba ngexesha lokucubungula okanye usetyenziso.
I-HMPC izinzile ngokushushu ukuya kuthi ga kwiqondo lobushushu elithile, apho iqala ukuthotywa. Ukushisa kokuthotywa kwe-HMPC kuxhomekeke kwi-DS kunye noxinzelelo lwepolymer kwisisombululo. Uluhlu lweqondo lokushisa lokuthotywa kwe-HMPC lubikwa ukuba luyi-190-330 ° C.
Udibaniso lwe-HMPC:
I-HMPC yenziwe nge-etherification reaction ye-cellulose kunye ne-propylene oxide kunye ne-methylethylene oxide phambi kwe-alkaline catalyst. Ukusabela kuqhubeka ngamanyathelo amabini: okokuqala, amaqela e-methyl e-cellulose athatyathelwa indawo yipropylene oxide, kwaye ke amaqela e-hydroxyl aphinde athatyathelwe indawo yi-methyl ethylene oxide. I-DS ye-HMPC inokulawulwa ngokulungelelanisa umlinganiselo we-molar we-propylene oxide kwi-cellulose ngexesha lenkqubo yokudibanisa.
Ukusabela ngokuqhelekileyo kuqhutyelwa kwindawo enamanzi kwiqondo lokushisa eliphakamileyo kunye noxinzelelo. I-catalyst esisiseko idla ngokuba yi-sodium okanye i-potassium hydroxide, ephucula ukusebenza kwakhona kwamaqela e-cellulose hydroxyl ukuya kumakhonkco e-epoxide epropylene oxide kunye ne-methylethylene oxide. Imveliso yokusabela iye ingathathi hlangothi, ihlanjwe kwaye yomiswe ukufumana imveliso yokugqibela ye-HMPC.
I-HMPC inokuthi yenziwe ngokuphendula i-cellulose kunye ne-propylene oxide kunye ne-epichlorohydrin phambi kwee-catalysts ze-asidi. Le ndlela, eyaziwa ngokuba yinkqubo ye-epichlorohydrin, isetyenziselwa ukuvelisa i-cationic cellulose derivatives, ehlawuliswa kakuhle ngenxa yobukho bamaqela e-quaternary ammonium.
ukuququmbela:
I-HMPC yipolymer esebenzayo eneempawu ezibalaseleyo zekhemikhali ezifanelekileyo kwizicelo ezahlukeneyo kumashishini ahlukeneyo. I-synthesis ye-HMPC ibandakanya ukusabela kwe-etherification ye-cellulose kunye ne-propylene oxide kunye ne-methylethylene oxide phambi kwe-alkaline catalyst okanye i-acidic catalyst. Iimpawu ze-HMPC zinokulungiswa ngokulawula i-DS kunye nokugxilwa kwepolymer. Ukhuseleko kunye ne-biocompatibility ye-HMPC yenza ukuba ibe lukhetho olululo kwimixube yamayeza.
Ixesha lokuposa: Sep-18-2023