Kev tsim khoom siv tshuab thiab txheej txheem ntawm hydroxypropyl methylcellulose

Refined paj rwb - qhib - alkalizing - etherifying - neutralizing - cais - ntxuav - cais, ziab - pulverizing - ntim - tiav paj rwb qhib: cov paj rwb refined yog qhib kom tshem tawm hlau, thiab ces pulverized. Pulverized refined paj rwb yog nyob rau hauv daim ntawv ntawm cov hmoov, thiab nws particle loj yog 80 mesh thiab transmittance yog 100%. Txwv tsis pub, nws yooj yim rau agglomerate ua ke thaum lub sij hawm cov txheej txheem tshuaj tiv thaiv thiab txo cov etherification efficiency.

Alkalization: Ntxiv cov hmoov refined paj rwb tom qab qhib rau hauv ib qho inert hnyav, thiab qhib nws nrog alkali thiab dej mos kom swell lub lattice ntawm refined paj rwb, uas yog haum rau kev nkag mus ntawm etherifying tus neeg sawv cev molecules, thiab txhim kho cov uniformity ntawm etherification cov tshuaj tiv thaiv. . Cov alkali siv nyob rau hauv alkalization yog hlau hydroxide los yog organic puag. Tus nqi ntawm alkali ntxiv (los ntawm huab hwm coj, tib yam hauv qab no) yog 0.1-0.6 npaug ntawm cov paj rwb refined, thiab cov dej mos yog 0.3-1.0 npaug ntawm cov paj rwb refined; lub inert hnyav yog sib tov ntawm cawv thiab hydrocarbon, thiab tus nqi ntawm inert hnyav ntxiv yog refined paj rwb. 7-15 zaug: cov kuab tshuaj inert kuj tuaj yeem yog cawv nrog 3-5 carbon atoms (xws li cawv, propanol), acetone. Nws tuaj yeem yog aliphatic hydrocarbons thiab muaj ntxhiab hydrocarbons; kub yuav tsum tau tswj nyob rau hauv 0-35 ° C thaum lub sij hawm alkalization; Lub sijhawm alkalization yog li 1 teev. Kev hloov pauv ntawm qhov kub thiab lub sijhawm tuaj yeem txiav txim siab raws li qhov xav tau ntawm cov khoom siv thiab cov khoom.

Etherification: Tom qab kev kho alkalization, nyob rau hauv lub tshuab nqus tsev, etherification yog ua los ntawm kev ntxiv tus neeg sawv cev etherifying, thiab tus neeg sawv cev etherifying yog propylene oxide. Txhawm rau txo qhov kev noj ntawm tus neeg sawv cev etherifying, nyob rau hauv cov txheej txheem etherification, tus neeg sawv cev etherifying yog ntxiv rau ob zaug, tus nqi ntawm thawj qhov sib ntxiv yog 1-3.5 npaug ntawm cov paj rwb refined, thiab tag nrho cov nyiaj ntawm ob qhov ntxiv. yog 1.5-4 npaug ntawm cov paj rwb refined. sij hawm. Tom qab ntxiv tus neeg sawv cev etherifying thawj zaug, do ntawm qhov kub ntawm ≤30 ° C rau 45min-90min, tom qab ntawd kub txog 50-100 ° C rau etherification, lub sij hawm yog 1-5h, thiab tom qab ntawd txias mus rau ≤30 ° C , Ntxiv etherified Jing rau zaum ob thiab do, stirring lub sij hawm yog 30-120min, thiab ces kub li? ? ? Ua tawm etherification, lub sij hawm yog 1-4h, lub sij hawm no, cov paj rwb refined thiab etherifying tus neeg sawv cev siab react los tsim H-HPC.

Pulverization thiab ntim: cov khoom qhuav ntawm cov khoom tsim tam sim no yog pulverized thiab sieved. Qhov loj me me ntawm pulverized thiab sieved khoom ntawm qhov kev tsim khoom tam sim no yog 40 mesh thiab kev xa tawm yog 10096, lossis raws li cov neeg siv xav tau. Tom qab ntawd ntim nws tawm ntawm lub hoobkas.


Post lub sij hawm: Oct-13-2022