Hydroxypropyl methylcellulose (HPMC) yog ib qho tshuaj sib xyaw ua ke uas siv dav hauv ntau yam lag luam vim nws cov tshuaj lom neeg tshwj xeeb thiab cov khoom.
1. Cov tshuaj lom neeg muaj pes tsawg leeg:
a. Cellulose txha nraub qaum:
HPMC yog ib qho cellulose derivative, uas txhais tau tias nws yog los ntawm cellulose, ib qho polysaccharide ntuj pom muaj nyob rau hauv cov nroj tsuag cell phab ntsa. Cellulose muaj cov chav rov ua dua ntawm β-D-glucose txuas los ntawm β (1 → 4) glycosidic bonds.
b. Kev Hloov Chaw:
Hauv HPMC, cov hydroxyl (-OH) ntawm cov cellulose backbone yog hloov nrog methyl thiab hydroxypropyl pawg. Qhov kev hloov pauv no tshwm sim los ntawm kev sib xyaw ua ke etherification. Qib ntawm kev hloov pauv (DS) hais txog tus lej nruab nrab ntawm cov hydroxyl pawg hloov pauv ib chav glucose hauv cov saw cellulose. DS ntawm methyl thiab hydroxypropyl pawg sib txawv, uas cuam tshuam rau kev ua haujlwm ntawm HPMC.
2. Kev sib xyaw ua ke:
a. Kev sib xyaw ua ke:
HPMC yog synthesized los ntawm etherification reaction ntawm cellulose nrog propylene oxide thiab methyl chloride. Cov txheej txheem no cuam tshuam nrog reacting cellulose nrog propylene oxide los qhia hydroxypropyl pawg thiab tom qab ntawd nrog methyl chloride los qhia methyl pawg.
b. Qib ntawm kev tswj hwm lwm txoj hauv kev:
Lub DS ntawm HPMC tuaj yeem tswj tau los ntawm kev kho cov xwm txheej tshuaj tiv thaiv xws li kub, lub sijhawm tshuaj tiv thaiv, thiab kev sib xyaw ua ke ntawm cov tshuaj tiv thaiv.
3. Kev Ua Tau Zoo:
a. Kev yaj tau:
HPMC yaj tau hauv dej thiab qee cov kuab tshuaj organic, xws li methanol thiab ethanol. Txawm li cas los xij, nws qhov solubility txo qis nrog qhov hnyav molecular nce thiab qib kev hloov pauv.
b. Kev tsim zaj duab xis:
HPMC ua ib daim zaj duab xis pob tshab thiab yoog tau thaum yaj rau hauv dej. Cov zaj duab xis no muaj lub zog zoo thiab cov khoom thaiv.
C. Qhov Viscosity:
Cov tshuaj HPMC qhia txog tus cwj pwm pseudoplastic, txhais tau tias lawv cov viscosity txo qis nrog rau kev nce ntxiv ntawm shear rate. Qhov viscosity ntawm cov tshuaj HPMC nyob ntawm cov yam xws li concentration, molecular weight, thiab degree of substitution.
d. Kev khaws dej:
Ib qho ntawm cov yam ntxwv tseem ceeb ntawm HPMC yog nws lub peev xwm los khaws dej. Cov yam ntxwv no yog qhov tseem ceeb hauv ntau yam kev siv xws li cov ntaub ntawv tsim kho, qhov twg HPMC siv los ua cov khoom siv tuab thiab cov neeg sawv cev khaws dej.
e. Kev nplaum:
HPMC feem ntau siv ua cov nplaum hauv ntau yam lag luam vim nws muaj peev xwm los tsim cov kev sib txuas zoo rau ntau yam substrates.
4. Daim Ntawv Thov:
a. Kev lag luam tshuaj:
Hauv cov tshuaj, HPMC yog siv los ua tus binder, tus neeg sawv cev txheej zaj duab xis, tus neeg sawv cev tso tawm tswj, thiab viscosity modifier hauv cov qauv ntsiav tshuaj.
b. Kev lag luam tsim kho:
HPMC ntxiv rau hauv cov cement-based mortars, gypsum-based plasters thiab cov nplaum pobzeb kom txhim kho kev ua haujlwm, kev khaws dej thiab kev nplaum.
C. kev lag luam zaub mov:
Hauv kev lag luam khoom noj, HPMC yog siv los ua cov khoom ua kom tuab, stabilizer thiab emulsifier hauv cov khoom xws li cov kua ntses, cov khaub ncaws hnav thiab ice cream.
d. Cov khoom siv tu cev:
HPMC yog siv los ua cov khoom ua kom tuab, emulsifier thiab zaj duab xis tsim cov khoom siv hauv cov khoom siv tu tus kheej xws li tshuaj zawv plaub hau, tshuaj pleev thiab tshuaj pleev.
e. Xim thiab Txheej Txheem:
Hauv cov xim thiab cov tshuaj pleev xim, HPMC yog siv los txhim kho cov xim dispersion, viscosity tswj thiab dej khaws cia.
Hydroxypropylmethylcellulose (HPMC) yog ib qho tshuaj sib xyaw ua ke uas muaj ntau yam kev siv thoob plaws ntau yam lag luam. Nws cov tshuaj sib xyaw ua ke, kev tsim khoom thiab cov yam ntxwv ua rau nws yog ib qho khoom xyaw tseem ceeb hauv kev lag luam tshuaj, cov ntaub ntawv tsim kho, zaub mov, cov khoom siv tu tus kheej thiab cov xim / txheej. Kev nkag siab txog cov yam ntxwv ntawm HPMC tso cai rau kev siv kho kom haum rau ntau qhov chaw, ua rau nws siv dav thiab tseem ceeb hauv cov txheej txheem tsim khoom niaj hnub.
Lub sijhawm tshaj tawm: Lub Ob Hlis-22-2024