Zoo ntawm Hydroxypropyl Methyl Cellulose

Hydroxypropyl methylcellulose yog refined los ntawm paj rwb tom qab alkalization, siv propylene oxide thiab methyl chloride ua etherification agents, thiab dhau los ua ib tug series ntawm cov tshuaj los tsim cov non-ionic cellulose tov ether. Hydroxypropyl methylcellulose yog non-ionic cellulose ether, dawb nyob rau hauv tsos, tsw thiab tasteless. Qhov degree ntawm kev hloov pauv yog feem ntau. Nws cov khoom sib txawv nyob ntawm qhov piv ntawm cov ntsiab lus methoxyl rau hydroxypropyl cov ntsiab lus.

Ua ntej, ua ntej saib cov synthesis ntawm hydroxypropyl methylcellulose:

Cov paj rwb refined cellulose yog kho nrog alkali tov ntawm 35-40 ° C rau ib nrab ib teev, nias, thiab cov cellulose yog pulverized ntawm 35 ° C thiab zoo hnub nyoog, yog li ntawd qhov nruab nrab degree ntawm polymerization ntawm cov tau alkali fiber nyob rau hauv lub xav tau ntau yam. Muab cov alkali fiber ntau tso rau hauv lub tank etherification, ntxiv propylene oxide thiab methyl chloride ua ntu zus, etherify ntawm 50-80 ° C rau 5 teev, thiab qhov siab tshaj plaws yog kwv yees. Tom qab ntawd ntxiv qhov tsim nyog ntawm hydrochloric acid thiab oxalic acid rau hauv dej kub ntawm 90 ° C kom nthuav dav. Dehydrate hauv ib lub centrifuge. Thaum cov dej noo ntawm cov khoom qis dua 60%, ntxuav nws mus rau nruab nrab, thiab tom qab ntawd qhuav nws mus rau qis dua 5% nrog cua kub ntws ntawm 130 ° C. Thaum kawg smashed los ntawm 20-mesh sieve kom tau cov khoom tiav.

Khoom nta ntawm Hydroxypropyl Methyl Cellulose:

1. Hydroxypropyl methylcellulose yooj yim soluble hauv dej txias thiab yuav yaj hauv dej kub. Txawm li cas los xij, nws qhov kub thiab txias hauv dej kub yog siab dua li ntawm methylcellulose. Dissolution nyob rau hauv dej txias kuj zoo heev dua methyl cellulose.

2. Lub viscosity ntawm hydroxypropyl methylcellulose muaj feem xyuam rau qhov hnyav molecular, thiab lub viscosity siab thaum lub molecular hnyav. Kub kuj cuam tshuam rau nws cov viscosity, thaum kub nce, viscosity txo. Tab sis nws cov viscosity siab yog qis dua methyl cellulose. Nws cov tshuaj yog ruaj khov ntawm chav tsev kub.

Lub peev xwm tuav dej ntawm hydroxypropyl methylcellulose nyob ntawm nws cov nyiaj ntxiv, viscosity, thiab lwm yam, thiab nws cov dej tuav tau siab dua li ntawm methyl cellulose.

3. Hydroxypropyl methylcellulose ruaj khov rau cov kua qaub thiab alkali, thiab nws cov kua aqueous ruaj khov nyob rau hauv thaj tsam ntawm pH = 2-12. Caustic dej qab zib thiab cov txiv qaub dej tsis tshua muaj txiaj ntsig rau nws cov khoom, tab sis alkali tuaj yeem ua rau nws tawg thiab me ntsis nce nws 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. Hydroxypropyl methylcellulose tuaj yeem sib xyaw nrog cov dej-soluble polymers los ua ib qho kev sib xyaw, cov kua nplaum siab. Xws li polyvinyl cawv, pas dej dej hmoov ether, zaub pos hniav, thiab lwm yam.

Hydroxypropyl methylcellulose muaj cov enzyme zoo dua li methylcellulose, thiab nws cov kev daws yuav tsis tshua muaj enzyme degraded dua li methylcellulose.

5. Qhov adhesion ntawm hydroxypropyl methylcellulose thiab mortar qauv yog siab dua li ntawm methylcellulose.

Cov khib nyiab ntub dej yog cov cement, nplua aggregate, additives thiab dej, thiab ntau yam khoom raug txiav txim raws li kev ua tau zoo. Tom qab kev sib tov yog ntsuas thiab sib tov ntawm ib qho piv txwv ntawm qhov chaw sib tov, cov khoom sib tov yog thauj mus rau qhov chaw siv los ntawm lub tsheb sib tov thiab khaws cia rau hauv ib lub thawv tshwj xeeb, thiab cov dej sib tov yog siv nyob rau hauv ib lub sij hawm teev.

Yuav txiav txim qhov zoo ntawm hydroxypropyl methylcellulose li cas?

Kev txiav txim siab qhov zoo ntawm hydroxypropyl methylcellulose feem ntau yog nyob ntawm ob qhov ntsuas, ib qho yog qhov kev hloov pauv (DS) thiab lwm qhov yog purity. Feem ntau, cov khoom ntawm carboxymethyl cellulose sib txawv yog tias qhov kev hloov pauv txawv; qhov siab dua qhov kev hloov pauv, qhov muaj zog dua qhov solubility, thiab qhov zoo dua qhov pom thiab ruaj khov ntawm cov tshuaj. Raws li cov ntaub ntawv tseem ceeb, lub pob tshab ntawm carboxymethyl cellulose yog qhov zoo thaum qhov kev hloov pauv yog ~, thiab cov viscosity ntawm nws cov kua aqueous siab thaum pH tus nqi yog 6-9. Qhov ntawd yog hais tias, txhawm rau ntsuas qhov zoo ntawm carboxymethyl cellulose, nws yog ib qho tsim nyog yuav tsum muaj kev nkag siab zoo ntawm nws cov qib kev hloov pauv thiab purity. Ob qhov ntsuas no ua tau raws li qhov yuav tsum tau ua, uas txhais tau tias nws qhov zoo yog qhov zoo heev.