Hydroxypropyl methylcellulose (HPMC) yog ntau yam polymer nrog ntau yam kev siv hauv ntau yam lag luam, suav nrog tshuaj, khoom noj, kev tsim kho, thiab tshuaj pleev ib ce. Thaum xav txog nws cov thermal zog, nws yog ib qho tseem ceeb rau delve rau hauv nws tus cwj pwm hais txog qhov kub thiab txias hloov, thermal stability, thiab lwm yam phenomena.
Thermal Stability: HPMC pom zoo thermal stability tshaj qhov kub thiab txias. Nws feem ntau decomposes ntawm qhov kub thiab txias, feem ntau tshaj 200 ° C, nyob ntawm nws qhov hnyav molecular, qib ntawm kev hloov pauv, thiab lwm yam. Cov txheej txheem degradation cuam tshuam nrog kev sib cais ntawm cov pob txha cellulose thiab tso tawm cov khoom tawg yooj yim decomposition.
Iav Transition Temperature (Tg): Zoo li ntau cov polymers, HPMC tau hloov pauv iav los ntawm iav mus rau lub xeev rubbery nrog nce kub. Tg ntawm HPMC sib txawv nyob ntawm nws qib ntawm kev hloov pauv, qhov hnyav molecular, thiab cov ntsiab lus noo noo. Feem ntau, nws nyob ntawm 50 ° C mus rau 190 ° C. Saum toj no Tg, HPMC ua tau yooj yim dua thiab nthuav tawm cov molecular zog ntxiv.
Melting Point: Ntshiab HPMC tsis muaj qhov sib txawv vim nws yog amorphous polymer. Txawm li cas los xij, nws softens thiab tuaj yeem ntws ntawm qhov kub siab. Lub xub ntiag ntawm additives los yog impurities tuaj yeem cuam tshuam nws tus cwj pwm melting.
Thermal conductivity: HPMC muaj thermal conductivity tsawg piv rau cov hlau thiab lwm yam polymers. Cov cuab yeej no ua rau nws tsim nyog rau cov ntawv thov uas xav tau thermal rwb thaiv tsev, xws li hauv cov tshuaj ntsiav tshuaj lossis cov khoom siv hauv tsev.
Thermal Expansion: Zoo li feem ntau cov polymers, HPMC nthuav dav thaum cua sov thiab cog lus thaum txias. Lub coefficient ntawm thermal expansion (CTE) ntawm HPMC nyob ntawm tej yam xws li nws cov tshuaj muaj pes tsawg leeg thiab ua tej yam kev mob. Feem ntau, nws muaj CTE nyob rau hauv thaj tsam ntawm 100 txog 300 ppm / ° C.
Thaum tshav kub kub muaj peev xwm: Lub peev xwm kub ntawm HPMC yog cuam tshuam los ntawm nws cov qauv molecular, qib kev hloov pauv, thiab cov ntsiab lus noo noo. Nws feem ntau yog li ntawm 1.5 txog 2.5 J / g ° C. Qib siab ntawm kev hloov pauv thiab cov ntsiab lus noo noo yuav ua rau kom muaj peev xwm ua kom sov.
Thermal Degradation: Thaum raug kub siab rau lub sijhawm ntev, HPMC tuaj yeem raug thermal degradation. Cov txheej txheem no tuaj yeem ua rau muaj kev hloov pauv hauv nws cov qauv tshuaj, ua rau poob ntawm cov khoom xws li viscosity thiab mechanical zog.
Thermal Conductivity Enhancement: HPMC tuaj yeem hloov kho los txhim kho nws cov thermal conductivity rau cov kev siv tshwj xeeb. Incorporating fillers los yog additives, xws li hlau hais los yog carbon nanotubes, tuaj yeem txhim kho cov hluav taws xob hloov hluav taws xob, ua rau nws tsim nyog rau kev tswj xyuas thermal.
Daim Ntawv Thov: Nkag siab txog cov khoom siv hluav taws xob ntawm HPMC yog qhov tseem ceeb rau kev txhim kho nws txoj kev siv ntau yam. Hauv cov tshuaj, nws yog siv los ua ib daim ntawv khi, zaj duab xis qub, thiab tus neeg sawv cev tso tawm hauv cov ntsiav tshuaj. Hauv kev tsim kho, nws tau ua haujlwm hauv cov khoom siv cement los txhim kho kev ua haujlwm, adhesion, thiab tuav dej. Nyob rau hauv cov khoom noj thiab tshuaj pleev ib ce, nws ua hauj lwm raws li ib tug thickener, stabilizer, thiab emulsifier.
Hydroxypropyl methylcellulose (HPMC) nthuav tawm ntau yam ntawm cov khoom siv thermal uas ua rau nws tsim nyog rau ntau daim ntawv thov thoob plaws kev lag luam. Nws thermal stability, iav hloov pauv kub, thermal conductivity, thiab lwm yam ntxwv ua lub luag haujlwm tseem ceeb hauv kev txiav txim siab nws cov kev ua tau zoo hauv ib puag ncig thiab kev siv. Kev nkag siab txog cov khoom no yog qhov tseem ceeb rau kev siv HPMC zoo hauv ntau yam khoom thiab cov txheej txheem.
Post lub sij hawm: May-09-2024