IHydroxypropyl Methylcellulose (HPMC)yi-non-ionic cellulose ether esetyenziswa rhoqo, esetyenziswa kakhulu kwizixhobo zokwakha, amayeza, ukutya, ukugquma, nakwezinye iindawo. Uzinzo lokusebenza kwayo kunye nomgangatho wayo kuchaphazela ngokuthe ngqo isiphumo semveliso yokugqibela; ngoko ke, uvavanyo olucwangcisiweyo lwe-HPMC ngexesha lokuveliswa nokusetyenziswa kubaluleke kakhulu.
1. Uvavanyo lweMbonakalo kunye nePropati eSisiseko
Ngaphambi kokuvavanya, isampuli iqale ijongwe ngamehlo. I-HPMC esemgangathweni ophezulu kufuneka ibe ngumgubo omhlophe okanye omhlophe okwaziyo ukuhamba kakuhle, ongenamaqhuma, ivumba, okanye ukungcola. Isisombululo sayo samanzi kufuneka sibonakale okanye sibe mdaka kancinci, ngaphandle kwezinto ezixinzelelweyo ezicacileyo. Emva koko, umxholo wayo wokufuma uyamiselwa, ngokuqhelekileyo kusetyenziswa i-infrared moisture analyzer okanye indlela yokomisa (indlela yobunzima obungaguqukiyo ye-105℃). Iimveliso ezifanelekileyo zihlala zinomxholo wokufuma ongaphantsi kwe-5%.
Ukuchonga umxholo wothuthu kubonisa umxholo wokungcola kwayo okungekho kwindalo. Isampulu itshiswa kwisithando somlilo esingenasiphene kwi-550℃ ukuya kubunzima obungaguqukiyo. Umxholo wothuthu uhlala ufuneka ukuba ungadluli kwi-1.5%. Umxholo wothuthu ogqithisileyo uya kuchaphazela ukucaca kwesisombululo kunye nokuzinza kwe-viscosity.
2. Uvavanyo lwe-Viscosity
Ukuqina kokukhanya yenye yezona zibonakaliso zibalulekileyo zokusebenza kwe-HPMC, nto leyo echaza ngokuthe ngqo ukuqina kwayo, ukugcinwa kwamanzi, kunye nemiphumo yokwenza ifilimu. Uvavanyo lwenziwa ngokubanzi kusetyenziswa i-rotational viscometer (njengeBrookfield viscometer) okanye i-Ubbelohde capillary viscometer.
Ngexesha lovavanyo, uxinzelelo oluthile (ngesiqhelo yi-2%) yesisombululo samanzi se-HPMC luvavanywa kubushushu obuthile (ngesiqhelo yi-20 ± 0.1℃). Iintlobo ezahlukeneyo ze-HPMC zinemiqolo ye-viscosity eyahlukileyo kakhulu, efana ne-400, 15000, kunye ne-100000 mPa·s. I-viscosity elinganisiweyo kufuneka ihambelane noluhlu oluqhelekileyo lwemveliso; kungenjalo, ibonisa ukuba inqanaba layo le-polymerization okanye utshintsho aluzinzanga.
3. Uvavanyo lweDigri yoTshintsho (Umxholo weMethoxy kunye neHydroxypropoxy)
Ukusebenza kwe-HPMC kuxhomekeka kakhulu kumxholo wezinto ezithatha indawo yazo.
Umxholo we-methoxy (–OCH₃) uchaphazela ukunyibilika, ubushushu bejeli, kunye nomsebenzi womphezulu;
Umxholo we-hydroxypropoxy (–OCH₂CHOHCH₃) uchaphazela ukuguquguquka kunye nokugcinwa kwamanzi.
Iindlela zokuchonga zihlala zisebenzisa i-chemical titration okanye i-gas chromatography. Umzekelo, emva kwe-acid hydrolysis, isampuli ivelisa ii-alcohols ezifanelekileyo, ezithi emva koko zihlalutywe ngobungakanani nge-titration okanye i-chromatography. Iimveliso ze-HPMC ezifanelekileyo zihlala ziqulathe umxholo we-methoxyl oyi-19%–24% kunye nomxholo we-hydroxypropoxyl oyi-4%–12%.
4. Umlinganiselo wobushushu bejeli
Iimpawu ze-thermogelation ze-HPMC ziyinxalenye ebalulekileyo eyahlula kwezinye ii-ether ze-cellulose. Ngexesha lovavanyo, isisombululo samanzi se-HPMC siyafudunyezwa kancinci kwaye sivuselelwe, kwaye ubushushu apho isisombululo sitshintsha khona ukusuka kwi-clear ukuya kwi-turbid burekhodwa njengobushushu bayo bejeli.
Ngokubanzi, i-HPMC enomxholo ophezulu we-methoxyl inobushushu obuphantsi bejeli, ngelixa umxholo ophezulu we-hydroxypropoxyl ubangela ubushushu obuphezulu bejeli. Esi sibonakaliso sinxulumene nokuzinza kwemveliso kwizicelo ezifana nodaka lokwakha kunye nopende lwethebhulethi.
5. Uvavanyo lwexabiso le-pH kunye nokunyibilika
Emva kokulungisa isisombululo se-2% se-HPMC, i-pH yayo ilinganiswa kusetyenziswa imitha ye-pH. Uluhlu oluqhelekileyo yi-5.0–8.0. Ngaphakathi kolu luhlu, i-HPMC izinzile kwaye ayizukuchasana kakubi nezinto ezininzi ezingaphiliyo okanye izongezo.
Uvavanyo lokunyibilika luvavanya izinga lokusasazeka kwayo kunye nezinga lokunyibilika emanzini abandayo. I-HPMC esemgangathweni ophezulu kufuneka isasazeke ngokukhawuleza xa ixutywa, yenze isisombululo esifanayo nesicacileyo kwimizuzu engama-30.
6. Ukuchonga Ubunyulu Nokungcola
Ukufunyanwa kobunyulu kubandakanya ikakhulu uvavanyo lweentsimbi ezinzima, iikloridi, iisulfates, kunye nemida yeentsholongwane.
Umxholo wesinyithi esinzima (njenge-Pb) akufuneki udlule kwi-20 ppm; i-chloride ≤ 0.2%, i-sulfate ≤ 0.5%;
Kwizicelo zamayeza okanye zokutya, inani elipheleleyo leebhaktheriya, iibhaktheriya ze-coliform, kunye nenani le-mold/yeast nazo kufuneka zivavanywe ukuqinisekisa ukhuseleko.
7. Uhlalutyo lweThermogravimetric kunye neFourier Transform Infrared Spectroscopy
Ukuvavanya ngakumbi ulwakhiwo kunye nokuzinza kobushushu be-HPMC, uhlalutyo lwe-thermogravimetric (TGA) kunye ne-Fourier transform infrared spectroscopy (FTIR) zingasetyenziswa.
I-TGA iyakwazi ukubona utshintsho olukhulu lwe-HPMC kumaqondo obushushu ahlukeneyo, ngaloo ndlela imisela ubushushu bayo bokubola kobushushu kunye nobubanzi bozinzo;
I-FTIR ihlalutya ulwakhiwo lweqela elisebenzayo ngokusebenzisa iincopho zokufunxa, iqinisekisa ubukho beebhendi zokufunxa zeempawu ze--OH, -OCH₃, kunye ne--OCH₂CHOHCH₃ ukuqinisekisa ukuchaneka kwesakhiwo se-molecular.
Uvavanyo olucwangcisiweyo olukhankanyiweyo apha ngasentla luvumela uvavanyo olupheleleyo lweempawu ze-physicochemical kunye nokufaneleka kokusetyenziswa kwe-HPMC. Ukuqina, ubungakanani bokutshintshwa, kunye nomxholo wokufuma zezona zibonakaliso zolawulo lomgangatho; ngelixa i-pH, umxholo womlotha, kunye nobushushu be-gelation zibonisa amanqanaba okucubungula kunye nobunyulu bayo. Ukubambelela ngokungqongqo kwezi nkqubo zovavanyo akuqinisekisi nje kuphela uzinzo lwemveliso kunye nokusebenza okuzinzileyo kodwa kukwabonelela ngenkxaso yedatha ethembekileyo yokhuseleko kunyeukusetyenziswa ngokufanelekileyo kwe-HPMCkumashishini afana nokwakha, amayeza, kunye nokutya.
Ixesha leposi: Oktobha-31-2025