I-Hydroxyethyl cellulose (HEC) i-non-ionic, i-polymer e-soluble yamanzi ephuma kwi-cellulose ngokuguqulwa kweekhemikhali. Ifumana ukusetyenziswa kakhulu kumashishini ahlukeneyo ngenxa yeempawu zayo ezizodwa, njengokutyeba, ukuzinzisa, kunye nobuchule bokwenza ifilimu. Kwizicelo apho uzinzo lwe-pH lubalulekile, ukuqonda indlela i-HEC eziphatha ngayo phantsi kweemeko ezahlukeneyo ze-pH kubalulekile.
Ukuzinza kwe-pH ye-HEC kubhekiselele ekukwazini kwayo ukugcina ingqibelelo yesakhiwo, iimpawu ze-rheological, kunye nokusebenza kuluhlu lweendawo ze-pH. Oku kuzinza kubaluleke kakhulu kwizicelo ezifana neemveliso zokunyamekela komntu, amayeza, iingubo, kunye nezinto zokwakha, apho i-pH yendawo engqongileyo inokwahluka kakhulu.
Ulwakhiwo:
I-HEC ngokuqhelekileyo yenziwe ngokuphendula i-cellulose nge-ethylene oxide phantsi kweemeko ze-alkaline. Le nkqubo ibangela ukutshintshwa kwamaqela e-hydroxyl ye-cellulose backbone kunye namaqela e-hydroxyethyl (-OCH2CH2OH). Iqondo lokutshintshela (DS) libonisa umndilili wenani lamaqela e-hydroxyethyl ngeyunithi ye-anhydroglucose kwikhonkco leselulosi.
Iinkcazelo ngeempawu:
I-Solubility: I-HEC iyanyibilika emanzini kwaye yenza izisombululo ezicacileyo, ezibonakalayo.
I-Viscosity: Ibonisa i-pseudoplastic okanye i-shear-thinning behavior, oku kuthetha ukuba i-viscosity yayo iyancipha phantsi koxinzelelo lwe-chear. Le propati yenza kube luncedo kwizicelo apho ukuhamba kubalulekile, njengepeyinti kunye neengubo.
Ukuqina: I-HEC inika i-viscosity kwizisombululo, iyenza ixabiseke njenge-ejenti yokuqina kwiindlela ezahlukeneyo.
Ukwenza ifilimu: Inokwenza iifilimu eziguquguqukayo kunye nezicacileyo xa zomisiwe, eziluncedo kwizicelo ezifana nokunamathiswa kunye neengubo.
pH Ukuzinza kwe-HEC
Ukuzinza kwe-pH ye-HEC kuphenjelelwa zizinto ezininzi, kubandakanywa ukwakheka kweekhemikhali zepolymer, ukusebenzisana kunye nokusingqongileyo, kunye naziphi na izongezo ezikhoyo ekuqulunqweni.
Uzinzo lwe-pH ye-HEC kwiindidi ze-pH ezahlukeneyo:
1. I-Acidic pH:
Kwi-pH ene-acidic, i-HEC izinzile ngokubanzi kodwa inokufumana i-hydrolysis ixesha elide phantsi kweemeko ze-acidic ezinzima. Nangona kunjalo, kwizicelo ezininzi ezisebenzayo, ezifana neemveliso zokunyamekela komntu kunye neengubo, apho i-acidic pH idibene nayo, i-HEC ihlala izinzile ngaphakathi kwinqanaba le-pH eqhelekileyo (pH 3 ukuya ku-6). Ngaphaya kwe-pH 3, umngcipheko wokwanda kwe-hydrolysis, okukhokelela ekunciphiseni kancinci kwi-viscosity kunye nokusebenza. Kubalulekile ukubeka iliso kwi-pH yemixube equlethe i-HEC kwaye uhlengahlengise njengoko kuyimfuneko ukugcina uzinzo.
2. I-pH ephakathi:
I-HEC ibonisa ukuzinza okuhle kakhulu phantsi kweemeko ze-pH ezingathathi hlangothi (pH 6 ukuya kwi-8). Olu luhlu lwe-pH luqhelekile kwizicelo ezininzi, kubandakanya izinto zokuthambisa, amayeza, kunye neemveliso zasekhaya. I-HEC-equlethwe iifomyula zigcina i-viscosity yazo, iipropathi ezityebileyo, kunye nokusebenza ngokubanzi ngaphakathi kolu luhlu lwe-pH. Nangona kunjalo, izinto ezifana neqondo lokushisa kunye namandla e-ionic zinokuchaphazela uzinzo kwaye kufuneka ziqwalaselwe ngexesha lokuphuhliswa kokuqulunqwa.
3. I-alkaline pH:
I-HEC ayizinzile ngaphantsi kweemeko ze-alkaline xa kuthelekiswa ne-acidic okanye i-pH engathathi hlangothi. Kumanqanaba aphezulu e-pH (ngaphezu kwe-pH 8), i-HEC inokutshatyalaliswa, okubangelwa ukuhla kwe-viscosity kunye nokulahlekelwa kokusebenza. I-alkaline hydrolysis ye-ether linkages phakathi kwe-cellulose backbone kunye namaqela e-hydroxyethyl ingenzeka, ekhokelela kwi-chain scission kunye nokunciphisa ubunzima be-molecular. Ngoko ke, kwimixube ye-alkaline efana ne-detergents okanye izinto zokwakha, ezinye iipolymers okanye i-stabilizers zinokukhethwa ngaphezu kwe-HEC.
Izinto eziPhembelela ukuzinza kwe-pH
Izinto ezininzi zinokuchaphazela uzinzo lwe-pH ye-HEC:
I-Degree of Substitution (DS): I-HEC enamaxabiso aphezulu e-DS ithande ukuzinza ngakumbi kulo lonke uluhlu lwe-pH olubanzi ngenxa yokwanda kokutshintshwa kwamaqela e-hydroxyl ngamaqela e-hydroxyethyl, ephucula ukunyibilika kwamanzi kunye nokumelana ne-hydrolysis.
Ubushushu: Ubushushu obuphezulu bunokukhawulezisa ukusabela kweekhemikhali, kubandakanywa ne-hydrolysis. Ngoko ke, ukugcina ukugcinwa okufanelekileyo kunye nokushisa okusemgangathweni kubalulekile ekugcineni ukuzinza kwe-pH ye-HEC equlethe iifomyula.
Amandla e-Ionic: Uxinzelelo oluphezulu lweetyuwa okanye ezinye ii-ion ekuqulunqweni kunokuchaphazela ukuzinza kwe-HEC ngokuchaphazela ukunyibilika kwayo kunye nokusebenzisana kunye nama-molecule amanzi. Amandla e-Ionic kufuneka aphuculwe ukuze kuncitshiswe iziphumo zokungazinzi.
Izongezo: Ukufakwa kwezongezo ezifana ne-surfactants, i-preservatives, okanye i-agent ephazamisayo inokuchaphazela ukuzinza kwe-pH ye-HEC formulations. Uvavanyo lokuhambelana kufuneka lwenziwe ukuze kuqinisekiswe ukuhambelana okongeziweyo kunye nokuzinza.
Izicelo neeNgqwalasela zokuqulunqa
Ukuqonda uzinzo lwe-pH ye-HEC kubalulekile kubaqulunqi bamachiza kumashishini ahlukeneyo.
Nantsi eminye imiba engqamene nesicelo:
IiMveliso zoNyango loMntu: Kwii-shampoos, i-conditioners, kunye ne-lotions, ukugcina i-pH ngaphakathi koluhlu olufunwayo (ngokuqhelekileyo malunga nokungathathi hlangothi) luqinisekisa ukuzinza kunye nokusebenza kwe-HEC njenge-ejenti yokuqina kunye nokumisa.
I-Pharmaceuticals: I-HEC isetyenziselwa ukumiswa komlomo, izisombululo ze-ophthalmic, kunye ne-topical formulations. Uqulunqo kufuneka luqulunqwe kwaye lugcinwe phantsi kweemeko ezigcina uzinzo lwe-HEC ukuqinisekisa ukusebenza kakuhle kwemveliso kunye nobomi beshelufu.
Iingubo kunye neePaints: I-HEC iqeshwe njenge-rheology modifier kunye ne-thickener kwiipende ezisekelwe emanzini kunye neengubo. Abaqulunqi kufuneka balungelelanise iimfuno ze-pH kunye nezinye iindlela zokusebenza ezifana ne-viscosity, ukulinganisa, kunye nokwenziwa kwefilimu.
Izinto zokwakha: Kwimiqulu yesamente, i-HEC isebenza njenge-arhente yokugcina amanzi kwaye iphucula ukusebenza. Nangona kunjalo, iimeko ze-alkaline kwi-samente zinokucela umngeni ukuzinza kwe-HEC, kufuneke ukuba kukhethwe ngokucophelela kunye nohlengahlengiso lokuqulunqa.
I-Hydroxyethyl cellulose (HEC) inikezela ngeempawu ezixabisekileyo ze-rheological kunye nokusebenza kwizicelo ezahlukeneyo. Ukuqonda ukuzinza kwayo kwe-pH kubalulekile kwiifomyula ukuphuhlisa imixube ezinzileyo nesebenzayo. Nangona i-HEC ibonisa ukuzinza okulungileyo phantsi kweemeko ze-pH ezingathathi hlangothi, kufuneka kuqwalaselwe iindawo ezine-acidic kunye ne-alkaline ukukhusela ukuthotywa kunye nokuqinisekisa ukusebenza kakuhle. Ngokukhetha ibakala elifanelekileyo le-HEC, ukulungelelanisa iiparitha zokuqulunqa, kunye nokuphumeza iimeko ezifanelekileyo zokugcina, abaqulunqi banokusebenzisa izibonelelo ze-HEC kwiindawo ezininzi ze-pH.
Ixesha lokuposa: Mar-29-2024