IHydroxypropyl Methylcellulose (HPMC) yimveliso ebalulekileyo ye-cellulose ether esetyenziswe ngokubanzi kwiindawo ezininzi zoshishino ngenxa yeempawu zayo ezizodwa kunye neekhemikhali. Iimpawu zayo ze-viscosity yenye yezona zinto zibalulekileyo ze-HPMC, ezichaphazela ngokuthe ngqo ukusebenza kwayo kwizicelo ezahlukeneyo.
1. Iimpawu ezisisiseko ze-HPMC
I-HPMC yi-ether ye-cellulose ye-nonionic efunyenwe ngokutshintshela inxalenye yamaqela e-hydroxyl (-OH) kwi-molecule ye-cellulose kunye namaqela e-methoxy (-OCH3) kunye namaqela e-hydroxypropyl (-OCH2CH (OH) CH3). Inonyibiliko oluhle emanzini kunye nezinye izinyibilikisi eziphilayo, zenza izisombululo ze-colloidal ezicacileyo. I-viscosity ye-HPMC imiselwa ubukhulu becala bubunzima bayo bemolekyuli, iqondo lokuthatha indawo (DS, iDegree of Substitution) kunye nokusasazwa okubambeleyo.
2. Ukumiselwa kwe-viscosity ye-HPMC
I-viscosity yezisombululo ze-HPMC idla ngokulinganiswa ngokusebenzisa i-viscometer ejikelezayo okanye i-capillary viscometer. Xa ulinganisa, ingqalelo kufuneka ihlawulwe ekugxininiseni, ukushisa kunye nesantya se-shear yesisombululo, njengoko ezi zinto zinokuchaphazela kakhulu ixabiso le-viscosity.
Isisombululo soxinaniso: I-viscosity ye-HPMC iyanda ngokunyuka koxinzelelo lwesisombululo. Xa i-concentration ye-HPMC isisombululo iphantsi, intsebenziswano phakathi kwee-molecule iyancipha kwaye i-viscosity iphantsi. Njengoko ugxininiso lukhula, ukudibanisa kunye nokusebenzisana phakathi kweeamolekyu kuyanda, kubangela ukwanda okukhulu kwe-viscosity.
Ubushushu: I-viscosity yezisombululo ze-HPMC zibuthathaka kakhulu kubushushu. Ngokuqhelekileyo, njengoko iqondo lokushisa linyuka, i-viscosity yesisombululo se-HPMC iya kuncipha. Oku kungenxa yokwanda kweqondo lobushushu elikhokelela ekunyukeni kwentshukumo yeemolekyuli kunye nokuncipha konxibelelwano lwe-intermolecular. Kufuneka kuqatshelwe ukuba HPMC kunye izidanga ezahlukeneyo endaweni kunye nobunzima molekyuli babe novakalelo ezahlukeneyo ubushushu.
Izinga le-Shear: Izisombululo ze-HPMC zibonisa ukuziphatha kwepseudoplastic (ukuchetywa kwe-chear), okt i-viscosity iphezulu kumazinga aphantsi okucheba kwaye yehla ngamazinga aphezulu okucheba. Oku kuziphatha kubangelwa amandla okucheba alungelelanisa amatyathanga eemolekyuli ecaleni kwendlela yokucheba, ngaloo ndlela kuncitshiswe ukubanjiswa kunye nokusebenzisana phakathi kweeathom.
3. Izinto ezichaphazela i-HPMC viscosity
Ubunzima bemolekyuli: Ubunzima bemolekyuli ye-HPMC yenye yezinto eziphambili ezimisela i-viscosity yayo. Ngokuqhelekileyo, ubukhulu be-molecular weight, buphezulu i-viscosity yesisombululo. Oku kungenxa yokuba iimolekyuli ze-HPMC ezinobunzima obuphezulu bemolekyuli kunokwenzeka ukuba zenze uthungelwano olubambeneyo, ngokwenjenjalo zandisa ukukhuhlana kwangaphakathi kwesisombululo.
Iqondo lokutshintshwa kunye nokusasazwa okubambeleyo: Inani kunye nokuhanjiswa kwe-methoxy kunye ne-hydroxypropyl substituents kwi-HPMC nako kuchaphazela i-viscosity yayo. Ngokubanzi, iqondo eliphezulu le-methoxy substitution (DS), isezantsi i-viscosity ye-HPMC, kuba ukuqaliswa kwe-methoxy substituents kuya kunciphisa amandla okudibanisa i-hydrogen phakathi kwee-molecule. Ukuqaliswa kwe-hydroxypropyl substituents kuya kwandisa ukusebenzisana kwe-intermolecular, ngaloo ndlela kukhulise i-viscosity. Ukongezelela, ukusabalalisa okufanayo kwabatshintshi kunceda ukwenza inkqubo yesisombululo esizinzile kunye nokwandisa i-viscosity yesisombululo.
Ixabiso le-pH yesisombululo: Nangona i-HPMC iyipolymer engeyiyo i-ionic kwaye i-viscosity yayo ayikhathaleli utshintsho kwixabiso le-pH yesisombululo, ixabiso elibi kakhulu le-pH (i-acidic kakhulu okanye i-alkaline kakhulu) inokubangela ukuthotywa kwesakhiwo se-molecular. HPMC, ngaloo ndlela echaphazela viscosity.
4. Iinkalo zesicelo ze-HPMC
Ngenxa yeempawu zayo ezibalaseleyo ze-viscosity, i-HPMC isetyenziswa ngokubanzi kwiinkalo ezininzi:
Izinto zokwakha: Kwizinto zokwakha, i-HPMC isetyenziswa njenge-ejenti yokuqina kunye nokugcina amanzi ukuphucula ukusebenza kolwakhiwo kunye nokwandisa ukuxhathisa ukuqhekeka.
Umzi-mveliso wamachiza: Kwishishini lamachiza, i-HPMC isetyenziswa njenge-binder yeepilisi, i-agent eyenza ifilimu yee-capsules kunye ne-carrier yamachiza akhululwe ngokuzinzileyo.
Umzi-mveliso wokutya: I-HPMC isetyenziswa njenge-thickener kunye nezinzisi kushishino lokutya ukwenzela ukuveliswa kwe-ayisikrimu, ijeli kunye neemveliso zobisi.
Iimveliso zemichiza yemihla ngemihla: Kwiimveliso zemichiza yemihla ngemihla, i-HPMC isetyenziswa njenge-thickener kunye ne-stabilizer yokuveliswa kweshampu, ijeli yeshawa, intlama yamazinyo, njl.
Iimpawu ze-viscosity ze-HPMC zisisiseko sokusebenza kwayo okugqwesileyo kwizicelo ezahlukeneyo. Ngokulawula ubunzima bemolekyuli, iqondo lokutshintshwa, kunye neemeko zesisombululo se-HPMC, i-viscosity yayo inokulungiswa ukuhlangabezana neemfuno ezahlukeneyo zesicelo. Kwixesha elizayo, uphando olunzulu malunga nobudlelwane phakathi kwesakhiwo semolekyuli ye-HPMC kunye ne-viscosity iya kunceda ukuphuhlisa iimveliso ze-HPMC kunye nokusebenza okungcono kunye nokwandisa ngakumbi imimandla yesicelo sayo.
Ixesha lokuposa: Jul-20-2024