I-Hydroxypropyl methylcellulose (i-HPMC, i-Hydroxypropyl Methylcellulose) i-ether ye-cellulose ebalulekileyo, isetyenziswe ngokubanzi ekwakheni, amayeza, ukutya kunye nezinye iindawo, kwaye ixhaphake ngokukodwa kwizinto zokwakha. Ukugcinwa kwamanzi kwe-HPMC yenye yeepropati zayo ezibalulekileyo kwaye idlala indima ephambili ekusebenzeni kweemeko ezininzi zesicelo. Izinto ezichaphazela ukugcinwa kwamanzi kwe-HPMC ziquka isakhiwo se-molecular, i-degree of substitution, i-molecular weight, i-solubility, iqondo lokushisa eliphantsi, izongezo, njl.
1. Ubume bemolekyuli
I-HPMC yi-derivative cellulose ene-molecular structure inempembelelo ebalulekileyo ekugcineni amanzi. Isakhiwo se-molecular ye-HPMC iqukethe i-hydrophilic hydroxyl (-OH), i-lipophilic methyl (-CH₃) kunye ne-hydroxypropyl (-CH₂CHOHCH₃). Ubungakanani kunye nokusasazwa kwala maqela e-hydrophilic kunye ne-lipophilic anefuthe elithe ngqo ekusebenzeni kokugcinwa kwamanzi kwe-HPMC.
Indima yamaqela e-hydroxyl: Amaqela e-Hydroxyl ngamaqela e-hydrophilic anokwenza i-hydrogen bond kunye ne-molecule zamanzi, ngaloo ndlela inceda ukuphucula ukugcinwa kwamanzi kwe-HPMC.
Indima yamaqela e-methyl kunye ne-hydroxypropyl: La maqela a-hydrophobic kwaye angachaphazela ukunyibilika kunye nobushushu be-gelation ye-HPMC emanzini, ngaloo ndlela ichaphazela ukusebenza kokugcinwa kwamanzi.
2. Isidanga sokutshintshwa
Iqondo lokutshintsha (DS) libhekiselele kumndilili yenani lamaqela ehydroxyl endaweni yawo kwiimolekyuli zecellulose. Kwi-HPMC, i-degree of substitution of methoxy (-OCH₃) kunye ne-hydroxypropoxy (-OCH₂CHOHCH₃) idla ngokuxhalabisa, oko kukuthi, i-degree of substitution of methoxy (MS) kunye neqondo lokutshintshwa kwe-hydroxypropoxy (HP):
Iqondo eliphezulu lokutshintsha: Xa liphezulu iqondo lokutshintsha, kokukhona amaqela e-hydrophilic HPMC enawo, kwaye ngokwethiyori ugcino lwamanzi luya kuphuculwa. Nangona kunjalo, iqondo eliphezulu kakhulu lokutshintsha kunokukhokelela ekunyibilikeni okugqithisileyo, kwaye umphumo wokugcinwa kwamanzi unokuncitshiswa.
Iqondo eliphantsi lokutshintshwa: I-HPMC eneqondo eliphantsi lokutshintshwa inobunzima bokunyibilika emanzini, kodwa isakhiwo sothungelwano esenziweyo sinokuzinza ngakumbi, ngaloo ndlela sigcina ugcino lwamanzi olungcono.
Ukulungelelanisa iqondo lokutshintsha ngaphakathi kuluhlu oluthile kunokwandisa ugcino lwamanzi lwe-HPMC. Uluhlu lwesidanga esiqhelekileyo sokutshintsha ngokuqhelekileyo yi-19-30% ye-methoxy kunye ne-4-12% ye-hydroxypropoxy.
3. Ubunzima bemolekyuli
Ubunzima bemolekyuli ye-HPMC inempembelelo ebalulekileyo kugcino lwamanzi:
Ubunzima obuphezulu be-molecular: I-HPMC enobunzima obuphezulu be-molecular inamatyathanga amade eemolekyuli kwaye yenza isakhiwo sothungelwano esixineneyo, esinokubamba kunye nokugcina amanzi amaninzi, ngaloo ndlela kuphuculwe ukugcinwa kwamanzi.
Ubunzima bemolekyuli ephantsi: I-HPMC enobunzima obuphantsi bemolekyuli ineemolekyuli ezimfutshane kunye nomthamo ongenamandla wokugcina amanzi, kodwa inonyibiliko olulungileyo kwaye ifanelekile kwizicelo ezifuna ukunyibilika ngokukhawuleza.
Ngokuqhelekileyo, i-molecular weight range ye-HPMC esetyenziswa kwizinto zokwakha ukusuka kwi-80,000 ukuya kwi-200,000.
4. Ukunyibilika
I-solubility ye-HPMC ichaphazela ngokuthe ngqo ukugcinwa kwayo kwamanzi. Ukunyibilika okulungileyo kunceda i-HPMC ukuba isasazwe ngokupheleleyo kwi-matrix, ngaloo ndlela yenza isakhiwo esifanayo sokugcina amanzi. Ukunyibilika kuchatshazelwa:
Ubushushu bokuphelisa: I-HPMC inyibilika kancinci emanzini abandayo, kodwa inyibilika ngokukhawuleza kumanzi ashushu. Nangona kunjalo, ubushushu obuphezulu kakhulu kuya kubangela ukuba i-HPMC inyibilike kakhulu, ichaphazela ubume bayo bokugcina amanzi.
Ixabiso le-pH: I-HPMC inovelwano kwixabiso le-pH kwaye inonyibiliko olungcono kwiindawo ezingathathi hlangothi okanye ezineasidi ebuthathaka. Inokuthi ithobe okanye inciphise ukunyibilika phantsi kwee-pH ezigqithisileyo.
5. Ubushushu be-Ambient
Ubushushu bunempembelelo ebalulekileyo kugcino lwamanzi lwe-HPMC:
Ukushisa okuphantsi: Kwiqondo lokushisa eliphantsi, i-solubility ye-HPMC iyancipha, kodwa i-viscosity iphezulu, enokuthi yenze isakhiwo esizinzileyo sokugcina amanzi.
Ukushisa okuphezulu: Ubushushu obuphezulu bukhawulezisa ukuchithwa kwe-HPMC, kodwa kunokubangela umonakalo kwisakhiwo sokugcina amanzi kunye nokuchaphazela umphumo wokugcinwa kwamanzi. Ngokubanzi, ugcino lwamanzi olulungileyo lunokugcinwa ngaphantsi kwe-40℃.
6. Izongezo
I-HPMC isoloko isetyenziswa kunye nezinye izongezo kwizicelo ezisebenzayo. Ezi zongezo zinokuchaphazela ugcino lwamanzi lwe-HPMC:
Iiplastiki: ezifana ne-glycerol kunye ne-ethylene glycol, enokuphucula ukuguquguquka kunye nokugcinwa kwamanzi kwe-HPMC.
Iifayili: ezifana ne-gypsum kunye ne-quartz powder, ziya kuchaphazela ukugcinwa kwamanzi kwe-HPMC kwaye utshintshe iimpawu zayo zokusabalalisa kunye nokutshatyalaliswa ngokusebenzisana ne-HPMC.
7. Imiqathango yesicelo
Ukugcinwa kwamanzi kwe-HPMC kuya kuchaphazeleka phantsi kweemeko ezahlukeneyo zokusetyenziswa:
Iimeko zokwakha: ezifana nexesha lokwakha, ukufuma kokusingqongileyo, njl.njl. ziya kuchaphazela isiphumo sogcino lwamanzi lwe-HPMC.
Isixa sokusetyenziswa: Isixa se-HPMC sichaphazela ngqo ukugcinwa kwamanzi. Ngokubanzi, i-HPMC enedosi ephezulu ibonisa isiphumo esingcono sogcino lwamanzi kudaka lwesamente kunye nezinye izinto.
Kukho izinto ezininzi ezichaphazela ukugcinwa kwamanzi kwe-HPMC, kubandakanywa nesakhiwo sayo se-molecular, i-degree of substitution, ubunzima bemolekyuli, ukunyibilika, ubushushu be-ambient, izongezo, kunye neemeko zokwenyani zesicelo. Ngethuba lenkqubo yesicelo, ngokukhetha ngokufanelekileyo kunye nokulungelelanisa le miba, ukugcinwa kwamanzi okusebenzayo kwe-HPMC kunokulungiswa ukuhlangabezana neemfuno zemimandla eyahlukeneyo.
Ixesha lokuposa: Jun-24-2024