Gxininisa kwiCellulose ethers

Ngaba i-Hydroxyethyl Cellulose pH inovakalelo?

I-Hydroxyethylcellulose (HEC) i-polymer engekho i-ionic yamanzi e-soluble esetyenziswa ngokubanzi kwiingubo, izithambiso, izinto zokwakha, amayeza kunye namanye amashishini. Umsebenzi wayo oyintloko njenge-thickener, i-agent yokumisa, i-agent-forming agent kunye ne-stabilizer, enokuphucula kakhulu iimpawu ze-rheological zemveliso. I-HEC inokunyibilika okulungileyo, ukutyeba, ukwenza ifilimu kunye nokuhambelana, ngoko ithandwa kwiindawo ezininzi. Nangona kunjalo, malunga nokuzinza kwe-HEC kunye nokusebenza kwayo kwiindawo ezahlukeneyo ze-pH, yinto ebalulekileyo ekufuneka ithathelwe ingqalelo kwizicelo eziphathekayo.

Ngokubhekiselele kubuzaza be-pH, i-hydroxyethylcellulose, njengepolymer engeyiyo i-ionic, ngokwendalo ayinabungozi kutshintsho lwe-pH. Oku kwahlukile kwezinye ii-ionic thickeners (ezifana ne-carboxymethylcellulose okanye iipolymer ezithile ze-acrylic), eziqulethe amaqela e-ionic kwizakhiwo zabo ze-molecular kwaye zivame ukuhlukana okanye i-ionization kwiindawo ezine-acidic okanye i-alkaline. , ngaloo ndlela ichaphazela umphumo wokuqina kunye neempawu ze-rheological zesisombululo. Ngenxa yokuba i-HEC ayinayo intlawulo, umphumo wayo wokuqina kunye neempawu zokunyibilika zihlala zizinzile kuluhlu olubanzi lwe-pH (ngokuqhelekileyo i-pH 3 ukuya kwi-pH 11). Olu phawu luvumela i-HEC ukuba ilungelelanise kwiinkqubo ezahlukeneyo zokuqulunqa kwaye inokusebenzisa umphumo omhle wokuqina phantsi kweemeko ze-acidic, ezingathathi hlangothi okanye ezibuthathaka ze-alkaline.

Nangona i-HEC inozinzo olulungileyo phantsi kweemeko ezininzi ze-pH, ukusebenza kwayo kunokuchaphazeleka kwiindawo eziphakamileyo ze-pH, ezifana neendawo ezinobungozi kakhulu okanye i-alkaline. Ngokomzekelo, phantsi kweemeko ze-acidic kakhulu (pH <3), i-solubility ye-HEC ingancitshiswa kwaye umphumo wokuqina ungabalulekanga njengendawo engathathi hlangothi okanye encinci ye-acidic. Oku kungenxa yokuba ugxininiso lwe-hydrogen ion olugqithisileyo luya kuchaphazela ukuhambelana kwe-HEC ye-molecular chain, ukunciphisa ukukwazi kwayo ukusabalalisa kunye nokuvuvukala emanzini. Ngokufanayo, phantsi kweemeko ze-alkaline kakhulu (pH> 11), i-HEC inokutshatyalaliswa ngokuyinxenye okanye ukuguqulwa kweekhemikhali, okuchaphazela umphumo wayo wokuqina.

Ukongeza kwi-solubility kunye nemiphumo yokuqina, i-pH inokuchaphazela ukuhambelana kwe-HEC kunye namanye amacandelo okuqulunqa. Ngaphantsi kweendawo ezahlukeneyo ze-pH, ezinye izithako ezisebenzayo zinokuthi ionize okanye zidibanise, ngaloo ndlela zitshintshe ukusebenzisana kwazo ne-HEC. Ngokomzekelo, phantsi kweemeko ze-acidic, ezinye ii-ion zetsimbi okanye izithako ezisebenzayo ze-cationic zingenza ii-complexes kunye ne-HEC, ezibangela ukuba umphumo wayo wokuqina ube buthathaka okanye uphephe. Ngoko ke, ekuqulunqweni koyilo, ukusebenzisana phakathi kwe-HEC kunye nezinye izithako phantsi kweemeko ezahlukeneyo ze-pH kufuneka ziqwalaselwe ukuqinisekisa ukuzinza kunye nokusebenza kwenkqubo yonke.

Nangona i-HEC ngokwayo ingabonakali kancinci kwiinguqu ze-pH, izinga lokuchithwa kwayo kunye nenkqubo yokutshatyalaliswa inokuchaphazeleka yi-pH. I-HEC idla ngokuchithwa ngokukhawuleza phantsi kweemeko ezingathathi hlangothi okanye ezine-acidic encinci, ngelixa phantsi kweemeko ze-acidic kakhulu okanye i-alkaline inkqubo yokutshatyalaliswa inokucotha. Ngoko ke, xa ulungiselela izisombululo, kudla ngokucetyiswa ukuba kuqala ungeze i-HEC kwisisombululo se-aqueous esingathathi hlangothi okanye esisondeleyo sokuqinisekisa ukuba siyayichitha ngokukhawuleza kwaye ngokulinganayo.

I-Hydroxyethylcellulose (HEC), njenge-polymer engeyiyo i-ionic, ayinamvakalelo encinci kwi-pH kwaye inokugcina iziphumo ezizinzileyo zokuqina kunye neempawu ze-solubility phezu koluhlu olubanzi lwe-pH. Ukusebenza kwayo kuzinzile kuluhlu lwe-pH 3 ukuya kwi-pH ye-11, kodwa kwiindawo ezigqithiseleyo ze-asidi kunye ne-alkali, umphumo wayo wokuqina kunye nokunyibilika kunokuchaphazeleka. Ngoko ke, xa usebenzisa i-HEC, nangona kwiimeko ezininzi akukho mfuneko yokuhlawula ingqwalasela enkulu kwiinguqu ze-pH, phantsi kweemeko ezinzima, uvavanyo olufanelekileyo kunye nohlengahlengiso lusafuneka ukuqinisekisa ukuzinza kunye nokusebenza kwenkqubo.


Ixesha lokuposa: Oct-22-2024
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