HPMC (Hydroxypropyl Methylcellulose) yog ib qho dej-soluble polymer compound dav siv hauv tshuaj, khoom noj, kev tsim kho, tshuaj pleev ib ce thiab lwm yam lag luam. HPMC yog ib tug semi-synthetic cellulose derivative tau los ntawm kev hloov tshuaj ntawm natural cellulose, thiab feem ntau yog siv los ua ib tug thickener, stabilizer, emulsifier thiab nplaum.
Lub cev muaj zog ntawm HPMC
Lub melting point ntawm HPMC yog qhov nyuaj dua vim tias nws cov ntsiab lus melting tsis pom tseeb li cov khoom siv crystalline. Nws cov ntsiab lus melting yog cuam tshuam los ntawm cov qauv molecular, molecular hnyav thiab qib ntawm kev hloov ntawm hydroxypropyl thiab methyl pawg, yog li nws tuaj yeem sib txawv raws li HPMC cov khoom tshwj xeeb. Feem ntau, raws li cov dej-soluble polymer, HPMC tsis muaj qhov pom tseeb thiab zoo ib yam, tab sis softens thiab decomposes nyob rau hauv ib tug tej yam kub thiab txias.
Melting point range
Kev coj tus cwj pwm thermal ntawm AnxinCel®HPMC yog qhov nyuaj dua, thiab nws tus cwj pwm thermal decomposition feem ntau yog kawm los ntawm kev ntsuas thermogravimetric (TGA). Los ntawm cov ntaub ntawv, nws tuaj yeem pom tias qhov melting point ntawm HPMC yog kwv yees li ntawm 200.°C thiab 300°C, tab sis qhov ntau yam no tsis sawv cev rau qhov tseeb melting point ntawm tag nrho cov khoom HPMC. Cov khoom sib txawv ntawm HPMC tuaj yeem muaj qhov sib txawv ntawm cov ntsiab lus melting thiab thermal stability vim muaj cov yam ntxwv xws li qhov hnyav molecular, degree ntawm ethoxylation (degree ntawm kev hloov), degree ntawm hydroxypropylation (degree ntawm hloov).
Tsawg molecular hnyav HPMC: Feem ntau melts los yog softens ntawm qis kub, thiab tej zaum yuav pib pyrolyze los yog yaj nyob ib ncig ntawm 200°C.
Siab molecular hnyav HPMC: HPMC polymers nrog ntau dua molecular hnyav yuav xav tau ntau dua kub kom yaj los yog soften vim lawv ntev molecular chains, thiab feem ntau pib pyrolyze thiab yaj ntawm 250°C thiab 300°C.
Cov yam ntxwv cuam tshuam rau lub melting point ntawm HPMC
Molecular Luj: Qhov hnyav molecular ntawm HPMC muaj kev cuam tshuam ntau dua rau nws qhov melting point. Qhov hnyav molecular feem ntau txhais tau hais tias qis dua melting kub, thaum siab molecular hnyav yuav ua rau ntau dua melting point.
Qib ntawm kev hloov pauv: Qib ntawm hydroxypropylation (piv txwv li qhov hloov pauv ntawm hydroxypropyl hauv molecule) thiab qib ntawm methylation (piv txwv li kev hloov pauv ntawm methyl hauv cov molecule) ntawm HPMC kuj cuam tshuam rau nws qhov melting point. Feem ntau, kev hloov pauv ntau dua yuav ua rau muaj kev solubility ntawm HPMC thiab txo nws cov ntsiab lus melting.
Cov ntsiab lus noo noo: Raws li cov khoom siv dej-soluble, lub melting point ntawm HPMC kuj cuam tshuam los ntawm nws cov ntsiab lus noo noo. HPMC uas muaj cov ntsiab lus noo noo siab tuaj yeem raug hydration los yog ib feem ntawm kev tawg, ua rau muaj kev hloov pauv ntawm qhov kub thiab txias.
Thermal stability thiab decomposition kub ntawm HPMC
Txawm hais tias HPMC tsis muaj cov ntsiab lus melting nruj, nws cov thermal stability yog qhov qhia txog kev ua tau zoo. Raws li cov ntaub ntawv ntsuas thermogravimetric (TGA), HPMC feem ntau pib decompose nyob rau hauv qhov kub ntawm 250.°C rau 300°C. Qhov tshwj xeeb decomposition kub 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 HPMC daim ntawv thov
Hauv kev siv, qhov melting point thiab thermal stability ntawm HPMC yog ib qho tseem ceeb heev. Piv txwv li, hauv kev lag luam kws tshuaj, HPMC feem ntau yog siv los ua cov khoom siv rau cov tshuaj ntsiav, txheej zaj duab xis, thiab cov neeg nqa khoom rau cov tshuaj tiv thaiv-tso tawm. Hauv cov ntawv thov no, lub thermal stability ntawm HPMC yuav tsum tau ua kom tau raws li qhov yuav tsum tau ua ntawm qhov kub thiab txias, yog li kev nkag siab txog tus cwj pwm thermal thiab melting point ntau ntawm HPMC yog qhov tseem ceeb rau kev tswj cov txheej txheem ntau lawm.
Hauv kev tsim kho, AnxinCel®HPMC feem ntau yog siv los ua cov thickener hauv mortar qhuav, coatings thiab adhesives. Nyob rau hauv cov ntawv thov no, lub thermal stability ntawm HPMC kuj yuav tsum tau nyob rau hauv ib tug tej yam kev mob los xyuas kom meej tias nws tsis decompose thaum lub sij hawm tsim kho.
HPMC, raws li cov khoom siv polymer, tsis muaj qhov taw tes khov kho, tab sis nthuav tawm cov yam ntxwv ntawm softening thiab pyrolysis nyob rau hauv ib qho chaw kub. Nws cov ntsiab lus melting yog feem ntau ntawm 200°C thiab 300°C, thiab cov ntsiab lus melting tshwj xeeb nyob ntawm cov yam ntxwv xws li qhov hnyav molecular, qib ntawm hydroxypropylation, qib ntawm methylation, thiab cov ntsiab lus noo ntawm HPMC. Hauv cov ntawv thov sib txawv, kev nkag siab txog cov khoom siv thermal no yog qhov tseem ceeb rau nws txoj kev npaj thiab siv.
Post lub sij hawm: Jan-04-2025