IHydroxyethylcellulose (HEC) yipolima enyibilikayo emanzini esetyenziswa ngokuqhelekileyo kushishino nakuphando lwezenzululwazi. Isetyenziswa kakhulu njenge-thickener, i-agent-forming agent, i-adhesive, emulsifier kunye ne-stabilizer.
Iipropati ezisisiseko ze-HEC
I-HEC i-polymer engekho i-ionic yamanzi e-soluble, i-hydroxyethylated derivative efunyenwe kwi-cellulose ngokusebenzisa i-ethylation reaction. Ngenxa yobume be-non-ionic, ukuziphatha kwe-HEC kwisisombululo ngokuqhelekileyo akutshintshwanga kakhulu nge-pH yesisombululo. Ngokwahlukileyo, iipolymers ezininzi ze-ionic (ezifana ne-sodium polyacrylate okanye i-carbomers) zivakalelwa ngakumbi kwi-pH kuba imeko yazo yentlawulo iyatshintsha ngotshintsho kwi-pH, echaphazela ukunyibilika kunye nokujiya. ukusebenza kunye nezinye iimpawu.
Ukusebenza kwe-HEC kumaxabiso ahlukeneyo e-pH
I-HEC ngokubanzi inozinzo oluhle phantsi kweemeko ze-acidic kunye ne-alkaline. Ngokukodwa, i-HEC inokugcina i-viscosity yayo kunye neempawu ezityebileyo kwiindawo ezininzi ze-pH. Uphando lubonisa ukuba i-viscosity kunye nekhono lokuqina le-HEC lizinzile phakathi koluhlu lwe-pH ye-3 ukuya kwe-12. Oku kwenza i-HEC ibe yinto eguquguqukayo kakhulu kunye ne-stabilizer kwizicelo ezininzi zemizi-mveliso kwaye ingasetyenziswa phantsi kweemeko ezahlukeneyo ze-pH.
Nangona kunjalo, ukuzinza kwe-HEC kunokuchaphazeleka kumaxabiso aphezulu e-pH (njenge-pH engaphantsi kwe-2 okanye ngaphezulu kwe-13). Ngaphantsi kwezi meko, iintambo ze-molecular ze-HEC zinokungena kwi-hydrolysis okanye ukuchithwa, okubangelwa ukunciphisa i-viscosity yayo okanye utshintsho kwiipropati zayo. Ngoko ke, ukusetyenziswa kwe-HEC phantsi kwezi meko zinzima kufuna ingqalelo ekhethekileyo ukuzinza kwayo.
Iingqwalasela zesicelo
Kwizicelo eziphathekayo, uvakalelo lwe-pH lwe-HEC lukwanxulumene nezinye izinto, ezifana nobushushu, amandla e-ionic, kunye ne-polarity ye-solvent. Kwezinye izicelo, nangona utshintsho lwe-pH lunempembelelo encinci kwi-HEC, ezinye izinto zokusingqongileyo zinokwandisa le mpembelelo. Ngokomzekelo, phantsi kweemeko eziphezulu zeqondo lokushisa, i-HEC's molecular chain can hydrolyze ngokukhawuleza, ngaloo ndlela ibe nempembelelo enkulu ekusebenzeni kwayo.
Ukongezelela, kwezinye iifomyula, ezifana ne-emulsions, i-gel kunye neengubo, i-HEC isoloko isetyenziswa kunye nezinye izithako (ezifana ne-surfactants, i-salts okanye i-acid-base regulators). Ngeli nqanaba, nangona i-HEC ayinabungozi kwi-pH ngokwayo, lawa amanye amacandelo angachaphazela ngokungathanga ngqo ukusebenza kwe-HEC ngokuguqula i-pH. Ngokomzekelo, i-charge state yezinye i-surfactants itshintsha kumaxabiso ahlukeneyo e-pH, enokuthi ichaphazele intsebenziswano phakathi kwe-HEC kunye ne-surfactants, ngaloo ndlela iguqula iimpawu ze-rheological zesisombululo.
I-HEC i-polymer engekho i-ionic engabonakaliyo kwi-pH kwaye inokusebenza kakuhle kunye nokuzinza ngaphezu koluhlu olubanzi lwe-pH. Oku kuyenza isebenze ngokubanzi kwizicelo ezininzi, ngakumbi apho ukusebenza okuzinzileyo kwee-thickeners kunye nabangaphambili befilimu kufuneka. Nangona kunjalo, kusabalulekile ukuqwalasela indlela ukuzinza kunye nokusebenza kwe-HEC kunokuchaphazeleka phantsi kweemeko ezigqithisileyo ze-pH okanye xa zisetyenziswe kunye nezinye izithako ze-pH-sensitive. Kwimiba yobuzaza be-pH kwizicelo ezithile, kucetyiswa ukuba kuqhutywe uvavanyo oluhambelanayo kunye nokuqinisekiswa ngaphambi kokusetyenziswa kwangempela ukuqinisekisa ukuba i-HEC inokusebenza kakuhle phantsi kweemeko ezilindelekileyo.
Ixesha lokuposa: Aug-19-2024