HPMC (Hydroxypropyl Methylcellulose) yog cov tshuaj polymer uas yaj tau hauv dej uas siv dav hauv kev lag luam tshuaj, khoom noj, kev tsim kho, tshuaj pleev ib ce thiab lwm yam lag luam. HPMC yog cov cellulose derivative semi-synthetic tau los ntawm kev hloov kho tshuaj ntawm cov cellulose ntuj, thiab feem ntau yog siv ua cov khoom tuab, stabilizer, emulsifier thiab nplaum.
Cov khoom siv lub cev ntawm HPMC
Lub ntsiab lus yaj ntawm HPMC nyuaj dua vim tias nws lub ntsiab lus yaj tsis pom tseeb li cov khoom siv crystalline ib txwm muaj. Nws lub ntsiab lus yaj yog cuam tshuam los ntawm cov qauv molecular, qhov hnyav molecular thiab qib ntawm kev hloov pauv ntawm hydroxypropyl thiab methyl pawg, yog li nws tuaj yeem hloov pauv raws li cov khoom HPMC tshwj xeeb. Feem ntau, ua cov polymer yaj hauv dej, HPMC tsis muaj lub ntsiab lus yaj meej thiab sib xws, tab sis mos thiab lwj hauv qee qhov kub.
Qhov ntau ntawm qhov kub yaj
Tus cwj pwm thermal ntawm AnxinCel®HPMC nyuaj dua, thiab nws tus cwj pwm thermal decomposition feem ntau yog kawm los ntawm thermogravimetric analysis (TGA). Los ntawm cov ntaub ntawv, nws tuaj yeem pom tias qhov melting point ntau ntawm HPMC yog kwv yees li ntawm 200°C thiab 300°C, tab sis qhov ntau no tsis sawv cev rau qhov tseeb melting point ntawm txhua yam khoom HPMC. Cov khoom sib txawv ntawm HPMC yuav muaj cov ntsiab lus melting thiab thermal stability sib txawv vim yog cov yam xws li qhov hnyav molecular, qib ntawm ethoxylation (qib ntawm kev hloov pauv), qib ntawm hydroxypropylation (qib ntawm kev hloov pauv).
HPMC uas tsis muaj molecular hnyav: Feem ntau yaj lossis mos thaum kub qis dua, thiab tej zaum yuav pib pyrolyze lossis yaj thaum nyob ib ncig ntawm 200°C.
HPMC hnyav molecular siab: HPMC polymers nrog qhov hnyav molecular siab dua yuav xav tau qhov kub siab dua kom yaj lossis mos vim lawv cov saw molecular ntev dua, thiab feem ntau pib pyrolyze thiab yaj ntawm 250°C thiab 300°C.
Cov yam tseem ceeb uas cuam tshuam rau qhov melting point ntawm HPMC
Qhov hnyav molecular: Qhov hnyav molecular ntawm HPMC muaj feem cuam tshuam ntau dua rau nws qhov melting point. Qhov hnyav molecular qis dua feem ntau txhais tau tias qhov kub melting qis dua, thaum qhov hnyav molecular siab yuav ua rau qhov melting point siab dua.
Qib ntawm kev hloov pauv: Qib ntawm hydroxypropylation (piv txwv li qhov piv ntawm kev hloov pauv ntawm hydroxypropyl hauv lub molecule) thiab qib ntawm methylation (piv txwv li qhov piv ntawm kev hloov pauv ntawm methyl hauv lub molecule) ntawm HPMC kuj cuam tshuam rau nws qhov melting point. Feem ntau, qib siab dua ntawm kev hloov pauv ua rau muaj kev yaj ntawm HPMC thiab txo nws qhov melting point.
Cov dej noo: Raws li cov khoom siv yaj hauv dej, qhov chaw yaj ntawm HPMC kuj raug cuam tshuam los ntawm nws cov dej noo. HPMC nrog cov dej noo siab tuaj yeem dhau los ua dej lossis ib feem yaj, ua rau muaj kev hloov pauv ntawm qhov kub thiab txias thermal decomposition.
Thermal stability thiab decomposition kub ntawm HPMC
Txawm hais tias HPMC tsis muaj qhov melting point nruj, nws qhov thermal stability yog qhov qhia tau zoo tseem ceeb. Raws li cov ntaub ntawv thermogravimetric analysis (TGA), HPMC feem ntau pib decompose hauv qhov kub ntawm 250°C txog 300°C. Qhov kub tshwj xeeb ntawm kev lwj yog nyob ntawm qhov hnyav molecular, qib kev hloov pauv thiab lwm yam khoom siv lub cev thiab tshuaj ntawm HPMC.
Kev kho cua sov hauv cov ntawv thov HPMC
Hauv cov ntawv thov, qhov kub thiab txias ntawm HPMC yog qhov tseem ceeb heev. Piv txwv li, hauv kev lag luam tshuaj, HPMC feem ntau siv ua cov khoom siv rau cov tshuaj ntsiav, cov txheej txheej zaj duab xis, thiab cov nqa khoom rau cov tshuaj tso tawm mus tas li. Hauv cov ntawv thov no, qhov kub thiab txias ntawm HPMC yuav tsum ua kom tau raws li qhov yuav tsum tau ua kom sov, yog li kev nkag siab txog tus cwj pwm thermal thiab qhov kub thiab txias ntawm HPMC yog qhov tseem ceeb rau kev tswj cov txheej txheem ntau lawm.
Hauv kev tsim kho, AnxinCel®HPMC feem ntau siv ua cov khoom ua kom tuab hauv cov mortar qhuav, cov tshuaj pleev xim thiab cov nplaum. Hauv cov ntawv thov no, qhov ruaj khov thermal ntawm HPMC kuj yuav tsum nyob hauv qee qhov ntau yam kom ntseeg tau tias nws tsis lwj thaum lub sijhawm tsim kho.
HPMC, ua ib yam khoom siv polymer, tsis muaj qhov chaw yaj tas, tab sis qhia txog cov yam ntxwv mos thiab pyrolysis hauv qee qhov kub thiab txias. Nws qhov chaw yaj feem ntau yog nruab nrab ntawm 200°C thiab 300°C, thiab qhov chaw yaj tshwj xeeb nyob ntawm cov yam xws li qhov hnyav molecular, qib ntawm hydroxypropylation, qib ntawm methylation, thiab cov dej noo ntawm HPMC. Hauv cov xwm txheej thov sib txawv, kev nkag siab txog cov khoom thermal no yog qhov tseem ceeb rau nws txoj kev npaj thiab siv.
Lub sijhawm tshaj tawm: Lub Ib Hlis-04-2025