Hydroxypropylcellulose (HEC) yog derivative ntawm cellulose, ib tug natural polymer pom nyob rau hauv cov nroj tsuag cell phab ntsa. HPC yog dav siv nyob rau hauv ntau yam lag luam xws li tshuaj, tshuaj pleev ib ce thiab khoom noj khoom haus kev lag luam vim nws zoo heev film-forming thiab thickening zog. Lub synthesis ntawm hydroxypropylcellulose muaj ntau cov kauj ruam thiab cov txheej txheem yuav complex.
Taw qhia rau hydroxypropylcellulose:
1. Siv cellulose ua cov khoom pib:
Qhov chaw tseem ceeb ntawm cellulose yog cov khoom siv cog xws li ntoo pulp lossis paj rwb. Cellulose yog ib hom kab hluav taws xob uas muaj cov piam thaj sib txuas los ntawm β-1,4-glycosidic bonds. Nws muaj qib siab ntawm polymerization, nrog ntau txhiab tus qabzib units ua cov saw ntev.
2. Cov tshuaj tiv thaiv Etherification:
Lub synthesis ntawm hydroxypropylcellulose koom nrog kev qhia txog cov pab pawg hydroxypropyl mus rau hauv cov pob txha cellulose ntawm etherification. Cov tshuaj tiv thaiv no feem ntau suav nrog kev siv propylene oxide ua tus neeg sawv cev alkylating.
Cellulose + propylene oxide → alkali-catalyzed hydroxypropyl cellulose + by-product cellulose + propylene oxide alkali-catalyzed hydroxypropyl cellulose + los ntawm cov khoom
Base catalysis yog qhov tseem ceeb los txhawb cov tshuaj tiv thaiv ntawm cellulose hydroxyl pawg thiab propylene oxide. Cov kauj ruam no feem ntau yog ua raws li kev tswj xyuas kom ntseeg tau tias qhov kev xav tau ntawm kev hloov pauv (DS) ntawm pawg hydroxypropyl ntawm cov saw cellulose.
3. Hydroxypropylation:
Hydroxypropylation suav nrog kev sib ntxiv ntawm hydroxypropyl pawg rau cov pob txha cellulose. Qhov kev hloov kho no imparts txhim kho solubility thiab lwm yam khoom tsim nyog rau cellulosic polymer. Cov kev mob tshwm sim, suav nrog qhov kub thiab txias, siab thiab lub sijhawm tshuaj tiv thaiv, ua tib zoo tswj kom ua tiav cov khoom xav tau.
4. Kev kho Alkali:
Tom qab hydroxypropylation, alkaline kev kho mob feem ntau yog siv los ua kom tsis muaj zog acidic impurities thiab kho cov pH ntawm cov tshuaj tiv thaiv sib tov. Cov kauj ruam no yog qhov tseem ceeb rau cov txheej txheem purification tom ntej.
5. Purification cov kauj ruam:
Tom qab cov tshuaj tiv thaiv etherification, ntau cov kauj ruam purification feem ntau yog ua kom tau txais high-purity hydroxypropylcellulose. Cov kauj ruam no yuav suav nrog:
Ntxuav: Ntxuav cov tshuaj tiv thaiv kom tshem tawm cov residual reagents, by-products thiab unreacted cellulose.
Filtration: Lim yog siv los cais cov khoom impurities los ntawm cov tshuaj tiv thaiv sib tov.
Kev ziab: Cov ntub dej hydroxypropyl cellulose yog tom qab ntawd qhuav kom tshem tawm cov dej noo ntxiv.
6. Molecular hnyav tswj:
Qhov hnyav molecular ntawm hydroxypropylcellulose tuaj yeem tswj tau thaum lub sijhawm sib xyaw kom haum nws cov khoom rau cov ntawv thov tshwj xeeb. Qhov no yog ua tiav los ntawm kev kho cov tshuaj tiv thaiv, xws li tus nqi ntawm reagents thiab lub sij hawm tshuaj tiv thaiv.
Industrial ntau lawm:
1. Cov txheej txheem tsis tu ncua lossis tsis tu ncua:
Kev tsim cov hydroxypropyl cellulose tuaj yeem ua tiav hauv batch lossis cov txheej txheem txuas ntxiv. Cov txheej txheem batch yog tsim rau cov khoom me me, thaum cov txheej txheem txuas ntxiv yog tsim nyog rau kev tsim khoom loj.
2. Kev tswj kom zoo:
Kev tswj xyuas kev ua tau zoo yog siv nyob rau txhua theem ntawm cov txheej txheem tsim khoom kom ntseeg tau tias qhov sib xws thiab purity ntawm cov khoom kawg. Cov txheej txheem tshuaj ntsuam xyuas xws li chromatography, spectroscopy thiab kev tshawb fawb rheological yog siv los ntsuas qhov tseem ceeb xws li qib kev hloov pauv, qhov hnyav molecular thiab purity.
Kev siv ntawm Hydroxypropyl Cellulose:
1. Pharmaceutical kev lag luam:
Hydroxypropylcellulose yog dav siv nyob rau hauv kev npaj tshuaj raws li ib tug binder, disintegrant thiab tswj tso tawm tus neeg sawv cev. Nws compatibility nrog ntau yam tshuaj thiab nws inertness ua rau nws muaj ntau yam excipient.
2. Kev lag luam tshuaj pleev ib ce:
Hauv kev lag luam tshuaj pleev ib ce, hydroxypropylcellulose yog siv rau hauv kev tsim cov khoom tu plaub hau, tshuaj pleev ib ce thiab lwm yam khoom siv tu tus kheej. Nws cov khoom ua yeeb yaj kiab ua rau nws muaj txiaj ntsig hauv cov khoom tu plaub hau.
3. Kev lag luam zaub mov:
Hauv kev lag luam zaub mov, hydroxypropylcellulose yog siv los ua cov thickener thiab gelling tus neeg sawv cev. Nws muaj nyob rau hauv ntau yam khoom noj thiab pab txhim kho lawv cov kev ntxhib los mos thiab ruaj khov.
Lub synthesis ntawm hydroxypropylcellulose koom nrog etherification ntawm cellulose los ntawm kev sib ntxiv ntawm hydroxypropyl pawg. Cov tshuaj tiv thaiv feem ntau yog catalyzed los ntawm lub hauv paus, ua raws li cov kauj ruam purification kom tau txais cov khoom ntshiab heev. Kev tsim khoom tuaj yeem ua tiav los ntawm batch lossis cov txheej txheem txuas ntxiv nrog kev tswj xyuas nruj. Hydroxypropylcellulose muaj ntau yam kev siv hauv kev lag luam tshuaj, tshuaj pleev ib ce thiab zaub mov vim nws cov khoom tshwj xeeb thiab ntau yam. Kev txhim kho tas mus li ntawm cov txheej txheem ntau lawm thiab kev tsim cov ntawv thov tshiab hais txog qhov
Post lub sij hawm: Dec-26-2023