Cov ntxhiab tsw ntawm hydroxypropyl methylcellulose cuam tshuam li cas?

Dab tsi yog qhov cuam tshuam ntawm tsw loj ntawm hydroxypropyl methylcellulose:

Synthesis ntawmHydroxypropyl methylcellulose yog tsim los ntawm cov tshuaj: Kho cov paj rwb refined cellulose nrog lye ntawm 35-40 ° C rau ib nrab ib teev, nias, zuaj cov cellulose, thiab hnub nyoog kom zoo ntawm 35 ° C, thiaj li hais tias qhov nruab nrab degree ntawm polymerization ntawm cov alkali tau nyob rau hauv qhov yuav tsum tau muaj fiber ntau nyob rau hauv. Muab cov alkali fiber ntau tso rau hauv etherification kettle, ntxiv propylene oxide thiab methyl chloride ua ntu zus, thiab etherify ntawm 50-80 ° C rau 5 teev, qhov siab tshaj plaws yog li 1.8MPa. Tom qab ntawd ntxiv qhov tsim nyog ntawm hydrochloric acid thiab oxalic acid rau hauv dej kub ntawm 90 ° C los ntxuav cov khoom kom nthuav dav. Dehydrate hauv ib lub centrifuge. Ntxuav nrog dej kom txog thaum nruab nrab. Thaum cov dej noo ntawm cov khoom qis dua 60%, qhuav nws nrog cov cua kub ntawm 130 ° C kom txog thaum cov dej noo qis dua 5%.

HPMC tsim los ntawm txoj kev hnyav siv toluene thiab isopropanol ua cov kuab tshuaj. Yog tias kev ntxhua khaub ncaws tsis zoo, qee qhov tsw ntxhiab tsw yuav nyob twj ywm. Tam sim no, qhov zoo ntawm domestic hydroxypropyl methylcellulose HPMC txawv heev, thiab tus nqi sib txawv, ua rau nws nyuaj rau cov neeg muas zaub los xaiv txoj cai. Qhov no yog qhov teeb meem ntawm cov txheej txheem ntxuav, nws tsis cuam tshuam rau kev siv thiab tsis muaj teeb meem, ntshiab HPMC yuav tsum tsis txhob hnov ​​​​qab ammonia, hmoov txhuv nplej siab thiab cawv; AdulteratedHPMCfeem ntau tuaj yeem hnov ​​​​txhua yam tsw, txawm tias nws tsis qab los, nws yuav hnov ​​​​qhov hnyav. Txawm li cas los xij, hydroxypropyl methylcellulose ua los ntawm ntau lub tuam txhab muaj cov ntxhiab tsw tshwj xeeb thiab tsw ntxhiab tsw. Qhov zoo yog yeej tsis mus txog par.

Hypromellose yog tau los ntawm impregnating refined paj rwb nrog tsawg kua kom tau alkaline cellulose, ces ntxiv hnyav, etherification tus neeg saib xyuas, toluene, thiab isopropanol rau etherification cov tshuaj tiv thaiv, neutralizing ntxuav, ziab, crushing, thiab lwm yam. Zoo, yuav muaj ntxhiab tsw, yog li cov neeg siv tuaj yeem siv nrog kev ntseeg siab.