Hydroxypropylmethylcellulose (HPMC) yog ib qho khoom siv ntau yam polymer muab los ntawm ntuj cellulose. Nws yog feem ntau siv nyob rau hauv ntau yam kev lag luam, xws li tshuaj, khoom noj khoom haus, kev tsim kho thiab tshuaj pleev ib ce. Kev tsim khoom ntawm HPMC suav nrog ntau yam khoom siv raw thiab txheej txheem ntau kauj ruam.
Cellulose:
Source: Cov khoom tseem ceeb ntawm HPMC yog cellulose, complex carbohydrate pom nyob rau hauv cov nroj tsuag cell phab ntsa. Qhov feem ntau ntawm cellulose rau HPMC ntau lawm yog ntoo pulp, tab sis lwm qhov chaw xws li paj rwb linters kuj siv tau.
Kev npaj: Cellulose feem ntau yog kho kom tshem tawm impurities thiab tom qab ntawd ua tiav rau hauv daim ntawv tsim nyog rau kev hloov kho ntxiv.
Base:
Hom: Sodium hydroxide (NaOH) lossis potassium hydroxide (KOH) feem ntau yog siv los ua lub hauv paus thaum pib ntawm HPMC ntau lawm.
Kev Ua Haujlwm: Alkali yog siv los kho cellulose, ua rau nws o thiab rhuav tshem nws cov qauv. Cov txheej txheem no, hu ua alkalization, npaj cov cellulose rau cov tshuaj tiv thaiv ntxiv.
Alkali etherifying tus neeg sawv cev:
Hydroxypropylating tus neeg sawv cev: propylene oxide feem ntau yog siv los qhia cov pab pawg hydroxypropyl rau hauv cov pob txha cellulose. Cov kauj ruam no imparts solubility thiab lwm yam khoom uas xav tau rau cellulose.
Methylating agents: Methyl chloride los yog dimethyl sulfate feem ntau yog siv los qhia methyl pawg mus rau cov qauv cellulose, yog li txhim kho nws cov khoom tag nrho.
Methylating tus neeg sawv cev:
Methanol: Methanol feem ntau yog siv los ua cov kuab tshuaj thiab cov tshuaj reactant hauv cov txheej txheem methylation. Nws pab qhia methyl pawg rau hauv cov saw cellulose.
Hydroxypropylating tus neeg sawv cev:
Propylene oxide: Nws yog cov khoom siv tseem ceeb rau kev qhia cov pab pawg hydroxypropyl rau hauv cellulose. Cov tshuaj tiv thaiv ntawm propylene oxide thiab cellulose tshwm sim nyob rau hauv kev tswj xyuas.
catalyst:
Acid Catalyst: Ib qho kua qaub catalyst, xws li sulfuric acid, yog siv los txhawb cov tshuaj tiv thaiv etherification. Lawv pab tswj cov tshuaj tiv thaiv kab mob thiab cov khoom lag luam.
Solvent:
Dej: Dej feem ntau yog siv los ua cov kuab tshuaj ntawm ntau theem ntawm cov txheej txheem tsim khoom. Nws yog ib qho tseem ceeb rau dissolving reactants thiab txhawb cov tshuaj tiv thaiv ntawm cellulose thiab etherifying agents.
Neutralizer:
Sodium hydroxide (NaOH) los yog poov tshuaj hydroxide (KOH): siv los ua kom cov kua qaub catalysts thiab kho pH thaum lub sij hawm synthesis.
purifier:
Filter Aids: Muaj ntau yam khoom siv lim dej tuaj yeem siv los tshem tawm cov impurities thiab cov khoom tsis zoo los ntawm cov tshuaj tiv thaiv sib xyaw.
Detergents: Ntxuav nrog dej los yog lwm yam kuab tshuaj pab tshem tawm cov residual tshuaj thiab impurities los ntawm cov khoom kawg.
Desiccant:
Huab cua los yog qhov cub kom qhuav: Tom qab ua kom huv, cov khoom tuaj yeem ua cua lossis qhov cub kom qhuav kom tshem tawm cov kuab tshuaj seem thiab cov dej noo.
Tus neeg saib xyuas zoo:
Analytical Reagents: Ntau cov reagents yog siv rau kev tswj xyuas kom zoo los xyuas kom meej tias HPMC cov khoom ua tau raws li qhov yuav tsum tau ua thiab cov lus qhia tshwj xeeb.
Kev tsim cov hydroxypropyl methylcellulose cuam tshuam nrog kev hloov kho cellulose los ntawm cov tshuaj lom neeg ntau. Cov ntaub ntawv nyoos muaj xws li cellulose, alkali, etherifying tus neeg sawv cev, catalyst, hnyav, tus neeg sawv cev nruab nrab, tus neeg saib xyuas purifying thiab desiccant, uas ua lub luag haujlwm tseem ceeb hauv cov txheej txheem synthesis. Cov kev mob tshwj xeeb thiab cov tshuaj reagents siv yuav txawv nyob ntawm seb cov khoom xav tau thiab daim ntawv thov ntawm cov khoom siv hydroxypropyl methylcellulose kawg.
Post lub sij hawm: Dec-21-2023