MC yog methyl cellulose, uas tau txais los ntawm kev kho cov paj rwb refined nrog alkali, siv methyl chloride ua tus neeg sawv cev etherifying, thiab ua cellulose ether los ntawm ntau cov tshuaj tiv thaiv. Feem ntau, qhov degree ntawm kev hloov pauv yog 1.6 ~ 2.0, thiab cov solubility kuj txawv nrog ntau qib kev hloov pauv. belongs rau non-ionic cellulose ether.
(1) Kev tuav dej ntawmmethyl cellulosenyob ntawm nws cov nyiaj ntxiv, viscosity, particle fineness thiab dissolution tus nqi. Feem ntau, yog tias qhov sib ntxiv yog loj, qhov fineness yog me me, thiab cov viscosity loj, cov dej tuav tus nqi yog siab. Ntawm lawv, qhov sib ntxiv muaj qhov cuam tshuam loj tshaj plaws ntawm cov dej tuav tus nqi, thiab qib viscosity tsis yog proportional rau qib ntawm cov dej tuav tus nqi. Tus nqi dissolution feem ntau yog nyob ntawm qhov kev hloov kho saum npoo ntawm cov cellulose hais thiab qhov zoo ntawm cov khoom. Ntawm cov cellulose ethers saum toj no, methyl cellulose thiab hydroxypropyl methyl cellulose muaj cov dej tuav ntau dua.
(2) Methylcellulose yog soluble hauv dej txias, tab sis nyuaj rau yaj hauv dej kub, thiab nws cov kua dej yog ruaj khov heev nyob rau hauv thaj tsam ntawm pH = 3 ~ 12. Nws muaj kev sib raug zoo nrog cov hmoov txhuv nplej siab, cov pos hniav, thiab lwm yam thiab ntau surfactants. Thaum qhov kub nce mus txog qhov kub thiab txias, qhov tshwm sim ntawm gelation tshwm sim.
(3) Kev hloov ntawm qhov kub thiab txias yuav cuam tshuam rau cov dej tuav tus nqi ntawm methyl cellulose. Feem ntau, qhov kub thiab txias dua, qhov dej khaws cia tsis zoo. Yog hais tias lub mortar kub siab tshaj 40 ° C, cov dej tuav ntawm methyl cellulose yuav loj heev, uas yuav cuam tshuam rau kev ua hauj lwm ntawm mortar.
(4) Methyl cellulose muaj qhov cuam tshuam loj rau kev ua haujlwm thiab adhesion ntawm mortar. "Adhesion" ntawm no yog hais txog qhov adhesion ntawm tus neeg ua haujlwm lub cuab yeej applicator thiab phab ntsa substrate, uas yog, shear resistance ntawm lub mortar. Lub adhesion yog loj, shear resistance ntawm lub mortar yog loj, thiab lub zog yuav tsum tau los ntawm cov neeg ua hauj lwm nyob rau hauv cov txheej txheem siv kuj loj, thiab kev tsim kho ntawm lub mortar yog tsis zoo. Methylcellulose adhesion yog nyob rau theem nrab hauv cellulose ether cov khoom.
HPMC yog hydroxypropyl methyl cellulose, uas yog non-ionic cellulose tov ether ua los ntawm refined paj rwb tom qab alkali kev kho mob, siv propylene oxide thiab methyl chloride ua etherifying agents, thiab los ntawm ib tug series ntawm cov tshuaj tiv thaiv. Qhov kev hloov pauv feem ntau yog 1.2 txog 2.0. Nws cov khoom sib txawv nyob ntawm qhov kev faib ua feem ntawm cov ntsiab lus methoxyl thiab hydroxypropyl cov ntsiab lus.
(1) Hydroxypropyl methylcellulose yog yooj yim soluble nyob rau hauv dej txias, tab sis nws yuav ntsib teeb meem nyob rau hauv dissolving nyob rau hauv dej kub. Tab sis nws qhov kub thiab txias hauv dej kub yog siab dua li ntawm methyl cellulose. Kev sib cais hauv dej txias kuj tseem txhim kho zoo dua piv nrog methyl cellulose.
(2) Lub viscosity ntawm hydroxypropyl methylcellulose muaj feem xyuam rau qhov loj ntawm nws qhov hnyav molecular, thiab qhov loj dua qhov hnyav molecular, qhov viscosity siab dua. Kub kuj cuam tshuam rau nws cov viscosity, thaum kub nce, viscosity txo. Tab sis nws cov viscosity tsawg cuam tshuam los ntawm qhov kub siab tshaj li methyl cellulose. Nws cov tshuaj yog ruaj khov nyob rau hauv cia ntawm chav tsev kub.
(3) Hydroxypropyl methylcellulose ruaj khov rau cov kua qaub thiab alkali, thiab nws cov tshuaj aqueous yog ruaj khov nyob rau hauv thaj tsam ntawm pH = 2 ~ 12. Caustic soda thiab txiv qaub dej tsis tshua muaj txiaj ntsig rau nws qhov kev ua tau zoo, tab sis alkali tuaj yeem ua kom nws tawg thiab ua kom cov viscosity. Hydroxypropyl methylcellulose yog ruaj khov rau cov ntsev ntau, tab sis thaum lub concentration ntawm cov ntsev ntsev yog siab, lub viscosity ntawm hydroxypropyl methylcellulose tov yuav nce.
(4) Kev tuav dej ntawmHydroxypropyl methylcellulose yog ib qho khoom siv zoonyob ntawm nws cov nyiaj ntxiv, viscosity, thiab lwm yam. Cov dej tuav tus nqi nyob rau hauv tib qhov sib ntxiv yog siab dua li ntawm methyl cellulose.
(5) Hydroxypropyl methylcellulose tuaj yeem sib xyaw nrog cov dej-soluble polymer compounds los tsim cov tshuaj sib xyaw thiab ntau dua viscosity. Xws li polyvinyl cawv, starch ether, zaub pos hniav, thiab lwm yam.
(6) Lub adhesion ntawm hydroxypropyl methylcellulose rau mortar siv yog siab dua li ntawm methylcellulose.
(7) Hydroxypropyl methylcellulose muaj kev tiv thaiv zoo dua rau cov enzymes dua li methylcellulose, thiab nws cov tshuaj enzymatic degradation muaj peev xwm qis dua li ntawm methylcellulose.
Lub sij hawm xa tuaj: Plaub Hlis-28-2024