Uyini umehluko phakathi kwe-hydroxyethyl cellulose ne-hydroxypropyl cellulose?

IHydroxyethyl Cellulose (HEC) kanye ne-hydroxypropyl cellulose (HPC) yizinto ezimbili ezivame ukusetshenziswa eziphuma ku-cellulose. Zinomehluko obalulekile ekwakhekeni, ekusebenzeni nasekusetshenzisweni kwawo.

1. Isakhiwo samakhemikhali
I-Hydroxyethyl cellulose (HEC): I-Hydroxyethyl cellulose yakhiwa ngokwethula iqembu le-hydroxyethyl (-CH₂CH₂OH) ku-molecule ye-cellulose. Iqembu le-hydroxyethyl linikeza i-HEC ukuncibilika okuhle nokuzinza.

I-Hydroxypropyl Cellulose (HPC): I-Hydroxypropyl cellulose yakhiwa ngokwethula iqembu le-hydroxypropyl (-CH₂CHOHCH₃) ku-molecule ye-cellulose. Ukwethulwa kwamaqembu e-hydroxypropyl kunikeza i-HPC izici ezihlukene zokuncibilika kanye nezici ze-viscosity.

2. Ukuncibilika
I-HEC: I-Hydroxyethylcellulose inokunyibilika okuhle emanzini futhi ingakha isisombululo se-colloidal esisobala. Ukuncibilika kwayo kuncike ezingeni lokushintsha kwamaqembu e-hydroxyethyl (okungukuthi inani lamaqembu e-hydroxyethyl ngeyunithi ngayinye ye-glucose).

I-HPC: I-Hydroxypropyl cellulose inokuncibilika okuthile kokubili emanzini nasezincibilikisini eziphilayo, ikakhulukazi kuzincibilikisi zemvelo njenge-ethanol. I-solubility ye-HPC ithintwa kakhulu izinga lokushisa. Njengoba izinga lokushisa likhuphuka, ukuncibilika kwayo emanzini kuzokwehla.

3. I-Viscosity kanye ne-rheology
I-HEC: I-Hydroxyethyl cellulose ine-viscosity ephezulu emanzini futhi ibonisa izakhiwo ze-pseudoplastic fluid, okungukuthi i-shear thinning. Lapho i-shear isetshenziswa, i-viscosity yayo iyancipha, okwenza kube lula ukuyisebenzisa nokusebenzisa.

I-HPC: I-Hydroxypropyl cellulose ine-viscosity ephansi futhi ibonisa i-pseudoplasticity efanayo esixazululweni. Izixazululo ze-HPC nazo zingakha ama-colloid asobala, kodwa i-viscosity yawo ngokuvamile iphansi kune-HEC.

4. Izindawo zokufaka izicelo
I-HEC: I-Hydroxyethyl cellulose isetshenziswa kakhulu ekubanjeni, ezintweni zokwakha, izimonyo, okokuhlanza neminye imikhakha. Njenge-thickener, stabilizer kanye ne-ejenti yokumisa, ingakwazi ukulawula ngempumelelo i-viscosity kanye ne-rheology yesistimu. Kumapende nakuma-coatings, i-HEC ivimbela ukuhlala kwe-pigment futhi ithuthukise ukuleveli kokunamathela.

I-HPC: I-Hydroxypropyl cellulose isetshenziswa kakhulu kwezemithi, ukudla, izimonyo neminye imikhakha. Embonini yezemithi, i-HPC ivamise ukusetshenziswa njenge-binder kanye ne-ejenti yokukhululwa elawulwayo yamaphilisi. Embonini yokudla, ingasetshenziswa njenge-thickener kanye ne-emulsifier. Ngenxa yokuncibilika kwayo kuzincibilikisi zemvelo, i-HPC iphinde isetshenziswe ezintweni ezithile zokunameka kanye ne-membrane.

5. Ukuzinza nokuqina
I-HEC: I-Hydroxyethyl cellulose inokusimama okuhle kwamakhemikhali nokuqina, ayithinteki ekushintsheni kwe-pH, futhi ihlala izinzile ngesikhathi sokugcinwa. I-HEC ihlala izinzile ngaphansi kwezimo zombili eziphezulu neziphansi ze-pH.

I-HPC: I-Hydroxypropyl cellulose iyazwela ekushintsheni kwezinga lokushisa ne-pH, futhi ijwayele ukugeleza ikakhulukazi emazingeni okushisa aphezulu. Ukuzinza kwayo kungcono ngaphansi kwezimo ze-acidic, kodwa ukuzinza kwayo kuzoncishiswa ngaphansi kwezimo ze-alkaline.

6. Imvelo kanye ne-biodegradability
I-HEC: I-Hydroxyethyl cellulose iphuma ku-cellulose yemvelo, inokubola okuhle kwe-biodegradability futhi inobungani nemvelo.

I-HPC: I-Hydroxypropyl cellulose nayo iyimpahla ebolayo, kodwa ukuziphatha kwayo okonakaliswa kungase kuhluke ngenxa yokuncibilika kwayo kanye nokwehlukahlukana kwezinhlelo zokusebenza.

I-Hydroxyethyl cellulose ne-hydroxypropyl cellulose yizinto ezimbili ezibalulekile eziphuma ku-cellulose. Nakuba bobabili benamandla okujiya, ukuzinzisa kanye nokwenza ama-colloid, ngenxa yokuhluka kwesakhiwo, banomehluko ekuncibilikeni, i-viscosity, kanye nezinkambu zokufaka isicelo. Kunomehluko omkhulu ekuzinzeni. Ukukhetha ukuthi iyiphi i-cellulose ephuma kokunye okuzosetshenziswa incike ezidingweni ezithile zohlelo lokusebenza kanye nezidingo zokusebenza.