Hydroxypropyl methylcellulose (HPMC) yog cov khoom siv sib xyaw ua ke uas tau siv dav hauv ntau lub lag luam vim nws cov tshuaj lom neeg muaj pes tsawg leeg thiab cov khoom.
1. Tshuaj muaj pes tsawg leeg:
a. Cellulose qaum:
HPMC yog cellulose derivative, uas txhais tau hais tias nws yog muab los ntawm cellulose, ib tug natural polysaccharide pom nyob rau hauv cov nroj tsuag cell phab ntsa. Cellulose muaj qhov rov ua dua ntawm β-D-glucose txuas los ntawm β (1 → 4) glycosidic bonds.
b. Hloov pauv:
Hauv HPMC, hydroxyl (-OH) moiety ntawm cellulose qaum yog hloov nrog methyl thiab hydroxypropyl pawg. Qhov kev hloov pauv no tshwm sim los ntawm cov tshuaj tiv thaiv etherification. Degree ntawm kev hloov pauv (DS) yog hais txog qhov nruab nrab ntawm cov pab pawg hydroxyl hloov ib chav tsev piam thaj hauv cov saw cellulose. Cov DS ntawm methyl thiab hydroxypropyl pawg sib txawv, uas cuam tshuam rau kev ua haujlwm ntawm HPMC.
2. Synthesis:
a. Etherification:
HPMC yog synthesized los ntawm etherification cov tshuaj tiv thaiv ntawm cellulose nrog propylene oxide thiab methyl chloride. Cov txheej txheem koom nrog reacting cellulose nrog propylene oxide los qhia hydroxypropyl pawg thiab tom qab ntawd nrog methyl chloride los qhia methyl pawg.
b. Degree ntawm lwm txoj kev tswj:
DS ntawm HPMC tuaj yeem tswj tau los ntawm kev kho cov tshuaj tiv thaiv xws li qhov kub thiab txias, lub sijhawm tshuaj tiv thaiv, thiab cov tshuaj reactant concentration.
3. Kev ua tau zoo:
a. Solubility:
HPMC yog soluble hauv dej thiab qee cov kuab tshuaj organic, xws li methanol thiab ethanol. Txawm li cas los xij, nws cov solubility txo qis nrog qhov hnyav molecular thiab qib hloov pauv.
b. Zaj duab xis tsim:
HPMC tsim cov duab pob tshab, hloov tau yooj yim thaum yaj hauv dej. Cov yeeb yaj kiab no muaj lub zog zoo txhua yam thiab cov khoom thaiv.
C. Viscosity:
HPMC cov kev daws teeb meem nthuav tawm tus cwj pwm pseudoplastic, txhais tau hais tias lawv cov viscosity txo qis nrog nce shear npaum li cas. Lub viscosity ntawm HPMC cov kev daws teeb meem yog nyob ntawm cov yam ntxwv xws li concentration, molecular hnyav, thiab qib kev hloov pauv.
d. Kev tuav dej:
Ib qho ntawm cov khoom tseem ceeb ntawm HPMC yog nws lub peev xwm khaws dej. Cov cuab yeej no yog qhov tseem ceeb hauv ntau daim ntawv thov xws li cov khoom siv tsim kho, qhov twg HPMC yog siv los ua cov thickener thiab dej-retaining agent.
e. Adhesion:
HPMC feem ntau yog siv los ua cov nplaum hauv ntau qhov kev lag luam vim nws muaj peev xwm tsim cov ntawv cog lus muaj zog rau cov substrates sib txawv.
4. Daim ntawv thov:
a. Pharmaceutical kev lag luam:
Hauv kev lag luam tshuaj, HPMC yog siv los ua ib qho kev sib khi, tus neeg saib xyuas zaj duab xis txheej, tswj kev tso tawm tus neeg sawv cev, thiab kev hloov kho viscosity hauv cov ntsiav tshuaj formulations.
b. Kev tsim kho kev lag luam:
HPMC yog ntxiv rau cement-based mortars, gypsum-based plasters thiab pobzeb nplaum los txhim kho kev ua haujlwm, dej tuav thiab adhesion.
C. Khoom noj khoom haus kev lag luam:
Hauv kev lag luam khoom noj khoom haus, HPMC yog siv los ua cov thickener, stabilizer thiab emulsifier hauv cov khoom xws li kua ntses, hnav khaub ncaws thiab dej khov.
d. Cov khoom siv tu tus kheej:
HPMC yog siv los ua cov thickener, emulsifier thiab zaj duab xis-tsim tus neeg sawv cev hauv cov khoom tu tus kheej xws li tshuaj zawv plaub hau, tshuaj pleev thiab pleev.
e. Paints thiab Coatings:
Hauv cov xim thiab txheej, HPMC yog siv los txhim kho cov xim dispersion, viscosity tswj thiab tuav dej.
Hydroxypropylmethylcellulose (HPMC) yog qhov sib xyaw ua ke nrog ntau yam kev siv thoob plaws ntau yam kev lag luam. Nws cov tshuaj lom neeg muaj pes tsawg leeg, synthesis thiab cov khoom ua rau nws yog ib qho tseem ceeb ntawm cov tshuaj, cov khoom siv hauv tsev, khoom noj khoom haus, cov khoom tu tus kheej thiab cov xim / txheej. Kev nkag siab txog cov yam ntxwv ntawm HPMC tso cai rau kev siv cov ntawv thov hauv ntau qhov chaw, ua rau nws siv dav thiab tseem ceeb hauv cov txheej txheem tsim khoom niaj hnub no.
Post lub sij hawm: Feb-22-2024