IHydroxypropyl Methylcellulose (HPMC) yinto ebalulekileyo ephuma kwi-cellulose ether esetyenziswa kakhulu kwiindawo ezininzi zoshishino ngenxa yeempawu zayo ezizodwa zomzimba nezekhemikhali. Iimpawu zayo ze-viscosity zezinye zezona mpawu zibalulekileyo ze-HPMC, ezichaphazela ngqo ukusebenza kwayo kwiindlela ezahlukeneyo zokusebenza.
1. Iimpawu ezisisiseko ze-HPMC
I-HPMC yi-nonion cellulose ether efunyenwe ngokutshintsha inxalenye yamaqela e-hydroxyl (–OH) kwi-molecule ye-cellulose ngamaqela e-methoxy (–OCH3) kunye namaqela e-hydroxypropyl (–OCH2CH(OH)CH3). Inyibilika kakuhle emanzini nakwezinye izinyibilikisi ze-organic, yenza izisombululo ze-colloidal ezibonakalayo. I-viscosity ye-HPMC ixhomekeke kakhulu kubunzima bayo be-molecular, iqondo lokutshintsha (DS, iDigri yokutshintsha) kunye nokusasazwa kwe-substituent.
2. Ukumisela ukuxinana kwe-HPMC
Ubungakanani be-viscosity yezisombululo ze-HPMC buhlala bulinganiswa kusetyenziswa i-viscometer ejikelezayo okanye i-capillary viscometer. Xa kulinganiswa, kufuneka kuqwalaselwe uxinaniso, ubushushu kunye nesantya sokucheba kwesisombululo, njengoko ezi zinto zinokuchaphazela kakhulu ixabiso le-viscosity.
Uxinzelelo lwesisombululo: Uxinzelelo lwe-HPMC luyanda ngokwanda koxinzelelo lwesisombululo. Xa uxinzelelo lwesisombululo se-HPMC luphantsi, ukusebenzisana phakathi kwee-molecules kuba buthathaka kwaye uxinzelelo luphantsi. Njengoko uxinzelelo lukhula, ukuxinana kunye nokusebenzisana phakathi kwee-molecules kuyanda, nto leyo ebangela ukwanda okukhulu koxinzelelo.
Ubushushu: Ubushushu obugqithisileyo bezisombululo ze-HPMC bubuthathaka kakhulu kubushushu. Ngokubanzi, njengoko ubushushu busanda, ubushushu obugqithisileyo besisombululo se-HPMC buya kuncipha. Oku kungenxa yobushushu obuphezulu obukhokelela ekunyukeni kwentshukumo yeemolekyuli kunye nobuthathaka bokusebenzisana phakathi kweemolekyuli. Kufuneka kuqatshelwe ukuba i-HPMC enamanqanaba ahlukeneyo okutshintsha kunye nobunzima beemolekyuli inobuthathaka obahlukileyo kubushushu.
Izinga lokucheba: Izisombululo ze-HPMC zibonisa ukuziphatha kwe-pseudoplastic (ukunciphisa ukucheba), oko kukuthi, i-viscosity iphezulu xa amazinga okucheba aphantsi kwaye iyancipha xa amazinga okucheba aphezulu. Oku kungenxa yamandla okucheba alungelelanisa imixokelelwane yeemolekyuli kwicala lokucheba, ngaloo ndlela kunciphisa ukuxinana kunye nokusebenzisana phakathi kweemolekyuli.
3. Izinto ezichaphazela ukuxinana kwe-HPMC
Ubunzima beMolekyuli: Ubunzima beMolekyuli ye-HPMC yenye yezinto ezibalulekileyo ezimisela i-viscosity yayo. Ngokubanzi, ubunzima beMolekyuli bukhulu, kokukhona i-viscosity yesisombululo iphezulu. Oku kungenxa yokuba iimolekyuli ze-HPMC ezinobunzima beMolekyuli obuphezulu zinokwenzeka ukuba zenze iinethiwekhi ezidityanisiweyo, ngaloo ndlela zonyusa ukungqubana kwangaphakathi kwesisombululo.
Umlinganiselo wokutshintshwa kunye nokusasazwa kwe-substituent: Inani kunye nokusasazwa kwe-methoxy kunye ne-hydroxypropyl substituents kwi-HPMC nako kuchaphazela i-viscosity yayo. Ngokubanzi, xa i-methoxy substituents iphezulu (DS), i-viscosity ye-HPMC iyancipha, kuba ukungeniswa kwe-methoxy substituents kuya kunciphisa amandla okubopha i-hydrogen phakathi kwee-molecules. Ukungeniswa kwe-hydroxypropyl substituents kuya kwandisa ukusebenzisana phakathi kwee-molecular, ngaloo ndlela kwandisa i-viscosity. Ukongeza, ukusasazwa okufanayo kwe-substituents kunceda ekwakheni inkqubo yesisombululo esizinzileyo kunye nokwandisa i-viscosity yesisombululo.
Ixabiso le-pH yesisombululo: Nangona i-HPMC iyi-polymer engeyiyo i-ionic kwaye i-viscosity yayo ayichaphazeleki kutshintsho kwixabiso le-pH yesisombululo, amaxabiso e-pH agqithisileyo (ane-asidi kakhulu okanye ane-alkaline kakhulu) anokubangela ukuwohloka kwesakhiwo se-molecular se-HPMC, ngaloo ndlela ichaphazela i-viscosity.
4. Iindawo zokusetyenziswa ze-HPMC
Ngenxa yeempawu zayo ezintle ze-viscosity, i-HPMC isetyenziswa kakhulu kwiinkalo ezininzi:
Izixhobo zokwakha: Kwizixhobo zokwakha, i-HPMC isetyenziswa njengesithambisi-manzi kunye nearhente yokugcina amanzi ukuphucula ukusebenza kolwakhiwo kunye nokwandisa ukumelana nokuqhekeka.
Ishishini lamayeza: Kwishishini lamayeza, i-HPMC isetyenziswa njengesihlanganisi seepilisi, iarhente yokwenza ifilimu yeekhaphu kunye nomthwali wamayeza akhutshwa rhoqo.
Ishishini lokutya: I-HPMC isetyenziswa njengesithambisi kunye nesiqinisi kwishishini lokutya ukuvelisa i-ayisikhrim, ijeli kunye neemveliso zobisi.
Iimveliso zeekhemikhali zemihla ngemihla: Kwiimveliso zeekhemikhali zemihla ngemihla, i-HPMC isetyenziswa njengesithambisi kunye nesiqinisi sokwenza ishampu, ijeli yeshawa, intlama yamazinyo, njl.
Iimpawu ze-viscosity ze-HPMC zisisiseko sokusebenza kwayo okugqwesileyo kwizicelo ezahlukeneyo. Ngokulawula ubunzima beemolekyuli, inqanaba lokutshintshwa, kunye neemeko zesisombululo se-HPMC, i-viscosity yayo inokulungiswa ukuze ihlangabezane neemfuno ezahlukeneyo zesicelo. Kwixesha elizayo, uphando olunzulu malunga nolwalamano phakathi kwesakhiwo semolekyuli ye-HPMC kunye ne-viscosity luya kunceda ukuphuhlisa iimveliso ze-HPMC ngokusebenza ngcono kwaye lwandise ngakumbi amasimi ayo esicelo.
Ixesha lokuposa: Julayi-20-2024