Koj puas paub txog hypromellose?

Hydroxypropyl methylcellulose (INN lub npe: Hypromellose), kuj yooj yim ua hypromellose (hydroxypropyl methylcellulose, luv uaHPMC), yog ntau yam nonionic cellulose sib xyaw ethers. Nws yog ib qho semi-synthetic, tsis ua haujlwm, viscoelastic polymer feem ntau siv ua lubricant hauv ophthalmology, lossis ua ib qho excipient lossis excipient hauv cov tshuaj noj, thiab feem ntau pom muaj nyob rau hauv ntau yam khoom lag luam.

Ua ib qho khoom noj khoom haus ntxiv, hypromellose tuaj yeem ua lub luag haujlwm hauv qab no: emulsifier, thickener, suspending agent thiab hloov rau tsiaj gelatin. Nws cov lej (E-code) hauv Codex Alimentarius yog E464.

Cov khoom siv tshuaj lom neeg:

Cov khoom tiav lawm ntawmhydroxypropyl methylcelluloseyog hmoov dawb los yog cov khoom siv fibrous dawb, thiab qhov loj ntawm cov khoom me me hla dhau 80-mesh sieve. Qhov sib piv ntawm cov ntsiab lus methoxyl rau cov ntsiab lus hydroxypropyl ntawm cov khoom tiav yog txawv, thiab viscosity yog txawv, yog li nws dhau los ua ntau yam nrog kev ua tau zoo sib txawv. Nws muaj cov yam ntxwv ntawm kev yaj hauv dej txias thiab tsis yaj hauv dej kub zoo ib yam li methyl cellulose, thiab nws cov solubility hauv cov organic solvents ntau dua li dej. Nws tuaj yeem yaj hauv anhydrous methanol thiab ethanol, thiab kuj tuaj yeem yaj hauv chlorinated hydrocarbons xws li dichloro methane, trichloroethane, thiab cov organic solvents xws li acetone, isopropanol, thiab diacetone cawv. Thaum yaj hauv dej, nws yuav sib xyaw nrog cov dej molecules los ua ib lub colloid. Nws ruaj khov rau acid thiab alkali, thiab tsis cuam tshuam rau hauv qhov ntau ntawm pH = 2 ~ 12. Hypromellose, txawm hais tias tsis muaj tshuaj lom, yog flammable thiab reacts violently nrog oxidizing agents.

Qhov viscosity ntawm HPMC cov khoom nce nrog rau qhov nce ntawm qhov concentration thiab molecular hnyav, thiab thaum qhov kub nce, nws cov viscosity pib txo qis. Thaum nws mus txog qee qhov kub, qhov viscosity tam sim ntawd nce thiab gelation tshwm sim. qhov siab ntawm. Nws cov kua dej ruaj khov ntawm chav tsev kub, tsuas yog tias nws tuaj yeem raug rhuav tshem los ntawm cov enzymes, thiab nws cov viscosity dav dav tsis muaj qhov tshwm sim degradation. Nws muaj cov khoom tshwj xeeb thermal gelation, cov khoom zoo-ua zaj duab xis thiab kev ua haujlwm ntawm qhov chaw.

Ua:

Tom qab cov cellulose raug kho nrog alkali, cov alkoxy anion tsim los ntawm deprotonation ntawm hydroxyl pawg tuaj yeem ntxiv propylene oxide los tsim hydroxypropyl cellulose ether; nws kuj tuaj yeem condense nrog methyl chloride los tsim methyl cellulose ether. Hydroxypropyl methylcellulose yog tsim tawm thaum ob qho kev cuam tshuam tau ua tiav tib lub sijhawm.

Siv:

Kev siv hydroxypropyl methylcellulose zoo ib yam li lwm cov cellulose ethers. Nws feem ntau yog siv ua tus neeg faib tawm, tus neeg sawv cev ncua, tus neeg ua kom tuab, emulsifier, stabilizer thiab nplaum hauv ntau qhov chaw. Nws zoo dua li lwm cov cellulose ethers hauv kev yaj, kev tawg, pob tshab thiab kev tiv thaiv enzyme.

Hauv kev lag luam khoom noj thiab tshuaj, nws yog siv los ua cov khoom ntxiv. Nws yog siv los ua cov nplaum, cov khoom ua kom tuab, cov khoom tawg, cov khoom ua kom mos, cov khoom ruaj khov thiab cov khoom ua kom emulsifier. Nws tsis muaj tshuaj lom, tsis muaj txiaj ntsig zoo rau kev noj haus, thiab tsis muaj kev hloov pauv hauv lub cev.

Tsis tas li ntawd,HPMCmuaj daim ntawv thov hauv cov khoom siv hluavtaws polymerization, petrochemicals, ceramics, papermaking, tawv, tshuaj pleev ib ce, coatings, cov ntaub ntawv tsim kho thiab cov phaj luam ntawv photosensitive.