Hydroxypropylmethylcellulose (HPMC) yog cellulose derivative siv dav hauv ntau yam lag luam. Kev siv tseem ceeb ntawm HPMC yog cov thickeners, stabilizers thiab emulsifiers hauv cov khoom noj, tshuaj thiab tshuaj pleev ib ce. HPMC kuj tseem siv rau hauv kev tsim kho raws li cov cement additive, ua txheej rau cov ntsiav tshuaj thiab tshuaj ntsiav, thiab ua tshuaj kho qhov muag. Cov ntaub ntawv tseem ceeb ntawm HPMC yog cellulose thiab tshuaj reagents.
Cellulose:
Cellulose yog cov khoom siv tseem ceeb rau kev tsim HPMC. Cellulose yog ib tug natural polymer pom nyob rau hauv cov nroj tsuag cell phab ntsa thiab yog cov feem ntau natural polymer nyob rau hauv lub ntiaj teb no. Cov khoom siv tshuaj lom neeg ntawm cellulose zoo ib yam li HPMC, uas ua rau nws yog ib qho khoom siv zoo tshaj plaws rau kev tsim HPMC. Cellulose yog muab los ntawm ntau qhov chaw, suav nrog ntoo, paj rwb, thiab ntau yam nroj tsuag.
Feem ntau qhov chaw ntawm cellulose siv rau HPMC ntau lawm yog ntoo pulp. Ntoo pulp yog muab los ntawm softwoods xws li spruce, ntoo thuv thiab fir. Ntoo pulp yog tshuaj kho kom tawg lignin thiab hemicellulose, tawm hauv cellulose ntshiab. Cov cellulose ntshiab yog ces bleached thiab ntxuav kom tshem tawm tej impurities.
Cellulose siv rau HPMC ntau lawm yuav tsum yog cov zoo thiab nruj zoo tswj kev ntsuas yuav tsum tau ua raws li los xyuas kom meej lub purity ntawm cellulose. Lub purity ntawm cellulose tseem ceeb heev vim impurities tuaj yeem cuam tshuam cov khoom ntawm cov khoom kawg.
Tshuaj reagent:
Kev tsim cov HPMC yuav tsum tau siv ntau yam tshuaj reagents. Tshuaj reagents siv nyob rau hauv zus tau tej cov HPMC muaj xws li propylene oxide, methyl chloride, sodium hydroxide, hydrochloric acid, thiab lwm yam.
Propylene oxide yog siv los tsim hydroxypropyl cellulose (HPC), uas yog tom qab ntawd reacted nrog methyl chloride los tsim HPMC. HPC reacts nrog methyl chloride los hloov qee pawg hydroxyl ntawm cov cellulose saw nrog methoxy thiab hydroxypropyl pawg, yog li tsim HPMC.
Sodium hydroxide yog siv rau hauv kev tsim HPMC kom nce pH tus nqi ntawm cov tshuaj tiv thaiv los pab yaj cellulose.
Thaum lub sijhawm HPMC cov txheej txheem tsim khoom, hydrochloric acid yog siv los kho pH tus nqi ntawm cov tshuaj tiv thaiv.
Cov tshuaj reagents siv nyob rau hauv HPMC ntau lawm yuav tsum muaj siab purity, thiab cov tshuaj tiv thaiv tej yam kev mob yuav tsum tau ua tib zoo tswj xyuas kom meej qhov zoo ntawm cov khoom kawg.
nyob rau hauv xaus:
Cov ntaub ntawv tseem ceeb ntawm HPMC yog cellulose thiab tshuaj reagents. Cellulose, muab tau los ntawm ntau qhov chaw xws li ntoo, paj rwb, thiab ntau yam nroj tsuag, yog thawj raw khoom rau kev tsim HPMC. Cov tshuaj reagents siv hauv HPMC ntau lawm suav nrog propylene oxide, methyl chloride, sodium hydroxide thiab hydrochloric acid. Kev tsim khoom ntawm HPMC yuav tsum muaj kev tswj xyuas nruj kom ntseeg tau tias cov khoom siv purity thiab qhov zoo ntawm cov khoom kawg. HPMC tau siv dav hauv ntau lub lag luam thiab muaj ntau yam kev siv vim nws cov khoom tshwj xeeb.
Post lub sij hawm: Sep-06-2023