Hydroxypropyl Methylcellulose (HPMC) ndi polima wofunikira wosungunuka m'madzi womwe umagwiritsidwa ntchito kwambiri muzamankhwala, chakudya, zokutira, zomangira ndi zina. The viscosity yankho la HPMC ndi chinthu chofunikira kwambiri chomwe chimakhudza magwiridwe antchito ake, ndipo kutentha kumakhudza kwambiri mamasukidwe amadzimadzi a HPMC.
1. Makhalidwe a viscosity ya yankho la HPMC
HPMC ndi zinthu polima ndi thermally zosinthika Kusungunuka katundu. Pamene HPMC imasungunuka m'madzi, njira yamadzimadzi yopangidwa ndi madzi imasonyeza makhalidwe omwe si a Newtonian fluid, ndiko kuti, kusintha kwa kukhuthala kwa kusinthika ndi kusintha kwa kumeta ubweya. Pa kutentha kwabwino, mayankho a HPMC nthawi zambiri amakhala ngati madzi a pseudoplastic, ndiko kuti, amakhala ndi mamasukidwe apamwamba pamitengo yotsika, ndipo mamasukidwe amachepa pamene kumeta ubweya kumawonjezeka.
2. Zotsatira za kutentha pa kukhuthala kwa HPMC yankho
Kusintha kwa kutentha kuli ndi njira ziwiri zazikulu zomwe zimakhudzira kukhuthala kwa HPMC njira zamadzimadzi: kuwonjezereka kwa kutentha kwa unyolo wa maselo ndi kusintha kwa mayankho a mayankho.
(1) Kuyenda kwa kutentha kwa unyolo wa maselo kumawonjezeka
Kutentha kumawonjezeka, kusuntha kwa matenthedwe a HPMC ma molekyulu kumawonjezeka, zomwe zimapangitsa kuti ma hydrogen bond ndi van der Waals pakati pa mamolekyu afooke ndi kuwonjezereka kwa yankho. Kukhuthala kwa yankho kumachepa chifukwa cha kuchepa kwapang'onopang'ono komanso kulumikizana pakati pa unyolo wa maselo. Chifukwa chake, mayankho amadzi a HPMC amawonetsa mamasukidwe otsika pamatenthedwe apamwamba.
(2) Kusintha kwa kuyanjana kwa mayankho
Kusintha kwa kutentha kungakhudze kusungunuka kwa mamolekyu a HPMC m'madzi. HPMC ndi polima ndi katundu thermogelling, ndi solubility ake m'madzi kusintha kwambiri ndi kutentha. Pa kutentha otsika, magulu hydrophilic pa HPMC maselo unyolo kupanga khola haidrojeni zomangira ndi mamolekyu amadzi, potero kukhalabe solubility wabwino ndi kukhuthala kwakukulu. Komabe, kutentha kukakwera kufika pamlingo wina, kuyanjana kwa hydrophobic pakati pa HPMC unyolo wa ma molekyulu kumakulitsidwa, zomwe zimapangitsa kuti pakhale mapangidwe atatu amtundu wa maukonde kapena gelation mu yankho, zomwe zimapangitsa kuti kukhuthala kwa njira kumawonjezeka mwadzidzidzi pazifukwa zina. Chodabwitsa ichi chimatchedwa Ndi "thermal gel" phenomenon.
3. Kuwona moyesera kutentha pa HPMC yankho kukhuthala
Kafukufuku woyeserera wasonyeza kuti mkati mwa kutentha kwanthawi zonse (mwachitsanzo, 20 ° C mpaka 40 ° C), kukhuthala kwa njira zamadzimadzi za HPMC kumachepa pang'onopang'ono ndikuwonjezera kutentha. Izi zili choncho chifukwa kutentha kwakukulu kumawonjezera mphamvu ya kinetic ya maunyolo a maselo ndi kuchepetsa kuyanjana kwa ma intermolecular, motero kumachepetsa kukangana kwa mkati mwa yankho. Komabe, pamene kutentha kukupitirirabe ku HPMC (nthawi zambiri pakati pa 60 ° C ndi 90 ° C, malingana ndi kuchuluka kwa m'malo ndi kulemera kwa maselo a HPMC), kukhuthala kwazitsulo kumawonjezeka mwadzidzidzi. Kuchitika kwa chodabwitsa ichi kumakhudzana ndi kulumikizidwa kwapawiri komanso kuphatikiza kwa unyolo wa ma cell a HPMC.
4. Ubale pakati pa kutentha ndi HPMC structural magawo
Yankho mamasukidwe akayendedwe a HPMC osati amakhudzidwa ndi kutentha, komanso zogwirizana kwambiri ndi maselo ake. Mwachitsanzo, kuchuluka kwa m'malo (mwachitsanzo, zomwe zili mu hydroxypropyl ndi methyl substituents) ndi kulemera kwa mamolekyulu a HPMC zimakhudza kwambiri machitidwe ake a gel ofunda. HPMC ndi mkulu mlingo m'malo amakhalabe kukhuthala m'munsi mu lonse kutentha osiyanasiyana chifukwa cha magulu ake kwambiri hydrophilic, pamene HPMC ndi digiri otsika m'malo ndi zambiri kupanga matenthedwe gel osakaniza. Kuphatikiza apo, mayankho a HPMC okhala ndi kulemera kwakukulu kwa maselo amatha kuwonjezera kukhuthala kwamphamvu pa kutentha kwambiri.
5. Malingaliro Ogwiritsa Ntchito Mafakitale ndi Othandiza
Pakugwiritsa ntchito, mitundu yoyenera ya HPMC imayenera kusankhidwa malinga ndi kutentha kwapadera. Mwachitsanzo, m'malo otentha kwambiri, HPMC yokhala ndi kutentha kwapamwamba iyenera kusankhidwa kuti ipewe kutentha kwa kutentha. Pansi pa kutentha kochepa, kusungunuka ndi kukhazikika kwa kukhuthala kwa HPMC kuyenera kuganiziridwa.
Zotsatira za kutentha pa mamasukidwe akayendedwe a HPMC amadzimadzi njira ali ndi zofunika zothandiza tanthauzo. M'munda wamankhwala, HPMC nthawi zambiri imagwiritsidwa ntchito ngati chinthu chokhazikika pokonzekera mankhwala, ndipo mawonekedwe ake a viscosity amakhudza mwachindunji kuchuluka kwa mankhwala. M'makampani azakudya, HPMC imagwiritsidwa ntchito kukonza mawonekedwe ndi kukhazikika kwazinthu, ndipo kudalira kwa kutentha kwa kukhuthala kwake kumayenera kusinthidwa malinga ndi kutentha kwamafuta. Pazomangamanga, HPMC imagwiritsidwa ntchito ngati chowonjezera komanso chosungira madzi, ndipo mawonekedwe ake a viscosity amakhudza ntchito yomanga ndi mphamvu zakuthupi.
Zotsatira za kutentha pa mamasukidwe akayendedwe a HPMC amadzimadzi njira ndi zovuta ndondomeko zokhudza kuyenda matenthedwe a unyolo maselo, mogwirizana yankho, ndi structural katundu wa polima. Ponseponse, mamasukidwe amadzimadzi a HPMC nthawi zambiri amachepetsa ndi kutentha, koma m'malo ena kutentha, kutentha kwa matenthedwe kumatha kuchitika. Kumvetsetsa izi kuli ndi tanthauzo lofunikira pakugwiritsa ntchito bwino komanso kukhathamiritsa kwa HPMC.
Nthawi yotumiza: Jul-10-2024