IHydroxyethyl cellulose (HEC) iyi-polymer engeyona i-ionic, encibilika emanzini etholakala ku-cellulose ngokuguqulwa kwamakhemikhali.Ithola ukusetshenziswa okubanzi ezimbonini ezahlukahlukene ngenxa yezakhiwo zayo ezihlukile, njengokujiya, ukusimamisa, kanye namakhono okwenza ifilimu.Kuzinhlelo zokusebenza lapho ukuzinza kwe-pH kubalulekile, ukuqonda ukuthi i-HEC iziphatha kanjani ngaphansi kwezimo ze-pH ezihlukene kubalulekile.
Ukuzinza kwe-pH kwe-HEC kubhekisela emandleni ayo okugcina ubuqotho besakhiwo, izakhiwo ze-rheological, nokusebenza kulo lonke uhla lwezindawo ze-pH.Lokhu kuzinza kubalulekile ezinhlelweni ezifana nemikhiqizo yokunakekelwa komuntu siqu, imithi, okokunamathela, nezinto zokwakha, lapho i-pH yendawo ezungezile ingahluka kakhulu.
Isakhiwo:
I-HEC ivamise ukwenziwa ngokuphendula i-cellulose ne-ethylene oxide ngaphansi kwezimo ze-alkaline.Le nqubo iholela ekufakweni kwamaqembu e-hydroxyl yomgogodla we-cellulose namaqembu e-hydroxyethyl (-OCH2CH2OH).I-degree of substitution (DS) ibonisa inani elimaphakathi lamaqembu e-hydroxyethyl ngeyunithi ngayinye ye-anhydroglucose kuketango le-cellulose.
Izakhiwo:
I-Solubility: I-HEC iyancibilika emanzini futhi yenza izixazululo ezicacile, ezibukekayo.
I-Viscosity: Ibonisa ukuziphatha kwe-pseudoplastic noma i-shear-thinning, okusho ukuthi i-viscosity yayo iyancipha ngaphansi kwengcindezi ye-shear.Lesi sakhiwo sikwenza kube usizo ezinhlelweni lapho ukugeleza kubalulekile, njengamapende nama-coatings.
Ukuqina: I-HEC inika i-viscosity ezixazululweni, iyenze ibe yigugu njenge-ejenti yokuqina ekwakhiweni okuhlukahlukene.
Ukwenza ifilimu: Kungakha amafilimu aguquguqukayo nasobala uma omisiwe, okuwusizo ekusetshenzisweni njengama-adhesives kanye nama-coatings.
I-pH Ukuzinza kwe-HEC
Ukuzinza kwe-pH ye-HEC kuthonywa izici eziningana, okuhlanganisa ukwakheka kwamakhemikhali e-polymer, ukusebenzisana nendawo ezungezile, nanoma yiziphi izithasiselo ezikhona ekwakhiweni.
Ukuzinza kwe-pH ye-HEC kumabanga ahlukene we-pH:
1. I-Acidic pH:
Ku-pH ene-asidi, i-HEC ngokuvamile izinzile kodwa ingase ithole i-hydrolysis isikhathi eside ngaphansi kwezimo ezine-asidi ezinzima.Kodwa-ke, ezinhlelweni eziningi ezisebenzayo, njengemikhiqizo yokunakekelwa komuntu siqu kanye nezingubo zokumboza, lapho kutholwa khona i-pH ene-asidi, i-HEC ihlala izinzile ngaphakathi kwebanga le-pH elijwayelekile (pH 3 kuya ku-6).Ngalé kwe-pH 3, ingozi ye-hydrolysis iyanda, okuholela ekwehleni kancane kancane kwe-viscosity nokusebenza.Kubalulekile ukuqapha i-pH yezinto ezakhiwe eziqukethe i-HEC futhi uzilungise njengoba kudingeka ukuze ulondoloze ukuzinza.
2. I-pH emaphakathi:
I-HEC ibonisa ukuzinza okuhle kakhulu ngaphansi kwezimo ze-pH ezingathathi hlangothi (pH 6 kuya ku-8).Lolu hlu lwe-pH luvamile ezinhlelweni eziningi, okuhlanganisa izimonyo, imithi, nemikhiqizo yasendlini.Amafomu aqukethe i-HEC agcina i-viscosity yawo, izakhiwo ezijiyayo, nokusebenza kukonke ngaphakathi kwalolu hlu lwe-pH.Kodwa-ke, izici ezifana nezinga lokushisa namandla e-ionic zingathonya ukuzinza futhi kufanele zicatshangelwe ngesikhathi sokuthuthukiswa kokubunjwa.
3. I-alkaline pH:
I-HEC azinzile ngaphansi kwezimo ze-alkaline uma iqhathaniswa ne-acidic noma i-pH engathathi hlangothi.Emazingeni aphezulu e-pH (ngaphezulu kwe-pH 8), i-HEC ingase ilahlekelwe, okuholela ekunciphiseni kwe-viscosity nokulahlekelwa ukusebenza.I-alkaline hydrolysis yokuxhumana kwe-ether phakathi komgogodla we-cellulose kanye namaqembu e-hydroxyethyl kungenzeka, okuholela ekwehleni kweketango nokuncipha kwesisindo samangqamuzana.Ngakho-ke, ekubunjweni kwe-alkaline njengezihlanzi noma izinto zokwakha, ama-polymers ahlukile noma iziqinisi zingakhethwa kune-HEC.
Izinto Ezithonya Ukuzinza kwe-pH
Izinto ezimbalwa zingathonya ukuzinza kwe-pH ye-HEC:
I-Degree of Substitution (DS): I-HEC enamanani aphezulu e-DS ijwayele ukuzinza kakhudlwana kulo lonke ibanga le-pH elibanzi ngenxa yokukhuphuka kwamaqembu e-hydroxyl namaqembu e-hydroxyethyl, okuthuthukisa ukuncibilika kwamanzi kanye nokumelana ne-hydrolysis.
Izinga lokushisa: Amazinga okushisa aphakeme angasheshisa ukusabela kwamakhemikhali, okuhlanganisa i-hydrolysis.Ngakho-ke, ukugcina izinga lokushisa elifanele lesitoreji kanye nokucubungula kubalulekile ukuze kulondolozwe ukuzinza kwe-pH ye-HEC-containing formulations.
Amandla e-Ionic: Ukugxila okuphezulu kosawoti noma amanye ama-ion ekwakhiweni kungathinta ukuzinza kwe-HEC ngokuthinta ukunyibilika kwayo nokusebenzisana nama-molecule amanzi.Amandla e-ionic kufanele athuthukiswe ukuze kuncishiswe imiphumela eqeda amandla.
Izengezo: Ukufakwa kwezithasiselo ezifana nama-surfactants, izilondolozi, noma ama-ejenti agcina izinga lokushisa kungathonya ukuzinza kwe-pH kokwakheka kwe-HEC.Ukuhlola ukuhambisana kufanele kwenziwe ukuze kuqinisekiswe ukuhambisana okungeziwe nokuzinza.
Izicelo Nokucatshangelwa Kokwakhiwa
Ukuqonda ukuzinza kwe-pH ye-HEC kubalulekile kubadidiyeli bezimboni ezihlukahlukene.
Nakhu okucatshangelwayo okuqondene nohlelo lokusebenza:
Imikhiqizo Yokunakekelwa Komuntu Siqu: Kuma-shampoos, ama-conditioner, nama-lotions, ukugcina i-pH ngaphakathi kwebanga elifunekayo (ngokuvamile lizungeze ukungathathi hlangothi) kuqinisekisa ukuzinza nokusebenza kwe-HEC njenge-ejenti ejiyayo neyimisayo.
Imithi: I-HEC isetshenziselwa ukumiswa komlomo, izixazululo ze-ophthalmic, kanye nokwakhiwa kwezihloko.Amafomu kufanele akhiwe futhi agcinwe ngaphansi kwezimo ezigcina ukuzinza kwe-HEC ukuze kuqinisekiswe ukusebenza kahle komkhiqizo nempilo yeshelufu.
Ama-Coatings and Paints: I-HEC iqashwe njenge-rheology modifier kanye ne-thickener kumapende asekelwe emanzini kanye nama-coatings.Abakhiqizi kufanele balinganisele izidingo ze-pH nezinye izimo zokusebenza ezifana ne-viscosity, ileveli, nokwakheka kwefilimu.
Izinto zokwakha: Ekwenziweni kukasimende, i-HEC isebenza njenge-ejenti yokugcina amanzi futhi ithuthukisa ukusebenza.Nokho, izimo ze-alkali kusimende zingabekela inselele ukuzinza kwe-HEC, kudinge ukukhethwa ngokucophelela nokulungiswa kokwakhiwa.
I-Hydroxyethyl cellulose (HEC) inikezela ngezakhiwo ezibalulekile ze-rheological kanye nokusebenza ekusebenzeni okuhlukahlukene.Ukuqonda ukuzinza kwayo kwe-pH kubalulekile ukuze abaklami bathuthukise ukwakheka okuzinzile nokusebenzayo.Nakuba i-HEC ibonisa ukuzinza okuhle ngaphansi kwezimo ze-pH ezingathathi hlangothi, kufanele kucatshangelwe izindawo ezine-acidic kanye ne-alkaline ukuvimbela ukuwohloka nokuqinisekisa ukusebenza kahle.Ngokukhetha ibanga elifanele le-HEC, ukuthuthukisa amapharamitha wokubunjwa, nokusebenzisa izimo ezifanele zokulondoloza, abaklami bangasebenzisa izinzuzo ze-HEC ezindaweni ezihlukahlukene ze-pH.
Isikhathi sokuthumela: Mar-29-2024