IHydroxyethyl cellulose (HEC) iyi-polymer engeyona i-ionic, encibilika emanzini etholakala ku-cellulose. Isetshenziswa kabanzi ezimbonini ezahlukahlukene, kufaka phakathi izinto zokunamathisela, lapho isebenza njenge-ejenti yokuqina, i-rheology modifier, kanye ne-stabilizer. Ikhono le-HEC lokuthuthukisa i-viscosity ye-adhesives ibalulekile ezinhlelweni eziningi, ukuqinisekisa ukusetshenziswa okufanele, ukusebenza, nokuphila isikhathi eside komkhiqizo wokunamathisela.
Izici ze-Hydroxyethyl Cellulose
I-HEC ikhiqizwa ngokusabela kwe-cellulose nge-ethylene oxide ngaphansi kwezimo ze-alkaline, okuholela ku-polymer enamaqembu e-hydroxyethyl ahlanganiswe nomgogodla we-cellulose. I-degree of substitution (DS) kanye ne-molar substitution (MS) amapharamitha angukhiye athonya izakhiwo ze-HEC. I-DS ibhekisela enanini elimaphakathi lamaqembu e-hydroxyl ku-molecule ye-cellulose ethathelwe indawo ngamaqembu e-hydroxyethyl, kuyilapho i-MS ibonisa inani elimaphakathi lama-moles e-ethylene oxide aphendule ngemvukuzane eyodwa yamayunithi e-anhydroglucose ku-cellulose.
I-HEC ibonakala ngokuncibilika kwayo emanzini, yakha izixazululo ezicacile nezisobala ezine-viscosity ephezulu. I-viscosity yayo ithonywa izici eziningana, okuhlanganisa isisindo samangqamuzana, ukugxila, izinga lokushisa, kanye ne-pH yesisombululo. Isisindo samangqamuzana e-HEC singasukela kokuphansi kuye phezulu kakhulu, okuvumela ukwakheka kwezinamatheliso ezinezidingo ezihlukene ze-viscosity.
Izindlela Zokuthuthukisa I-Viscosity
I-Hydration nokuvuvukala:
I-HEC ithuthukisa i-viscosity yokunamathisela ngokuyinhloko ngokusebenzisa ikhono layo lokufaka amanzi kanye nokuvuvukala emanzini. Lapho i-HEC yengezwe ekwakhiweni kwe-adhesive aqueous, amaqembu e-hydroxyethyl aheha ama-molecule amanzi, okuholela ekuvuvukeni kwamaketanga e-polymer. Lokhu kuvuvukala kwandisa ukumelana kwesisombululo ukugeleza, ngaleyo ndlela kwandise i-viscosity yayo. Ubukhulu bokuvuvukala kanye ne-viscosity ewumphumela kuthonywa ukugxila kwe-polymer kanye nesisindo samangqamuzana e-HEC.
I-Molecular Entanglement:
Ngesixazululo, ama-polymers we-HEC ayabanjwa ngenxa yesakhiwo sawo samaketanga amade. Lokhu kugoqa kwakha inethiwekhi evimbela ukunyakaza kwama-molecule ngaphakathi kwe-adhesive, ngaleyo ndlela kwandise i-viscosity. Isisindo samangqamuzana aphezulu i-HEC iphumela ekubambeni okubaluleke kakhulu kanye ne-viscosity ephakeme. I-degree of entanglement ingalawulwa ngokulungisa ukugxila kwe-polymer kanye nesisindo se-molecular ye-HEC esetshenzisiwe.
I-Hydrogen Bonding:
I-HEC ingakha izibopho ze-hydrogen ngama-molecule amanzi nezinye izakhi ekwakhiweni kokunamathela. Lezi zibopho ze-hydrogen zifaka isandla ku-viscosity ngokudala inethiwekhi ehlelekile ngaphakathi kwesixazululo. Amaqembu e-hydroxyethyl kumgogodla we-cellulose athuthukisa ikhono lokwakha amabhondi e-hydrogen, akhulise i-viscosity.
Ukuziphatha Kokunciphisa I-Shear:
I-HEC ibonisa ukuziphatha kokunciphisa i-shear, okusho ukuthi i-viscosity yayo iyancipha ngaphansi kwengcindezi ye-shear. Lesi sakhiwo sinenzuzo ezinhlelweni zokunamathela ngoba kuvumela ukusetshenziswa okulula ngaphansi kwe-shear (njengokusabalalisa noma ukuxubha) ngenkathi kugcinwa i-viscosity ephezulu lapho uphumule, iqinisekisa ukusebenza okuhle kokunamathela nokuzinza. Ukuziphatha kokunciphisa i-shear kwe-HEC kubangelwa ukulungiswa kwamaketanga e-polymer ekuqondeni kwamandla asetshenzisiwe, kunciphisa ukumelana kwangaphakathi okwesikhashana.
Izicelo ku-Adhesive Formulations
Izinamathiselo Ezisekelwe emanzini:
I-HEC isetshenziswa kakhulu ezintweni ezinamathelayo ezisekelwe emanzini, njengalezo zephepha, izindwangu, nokhuni. Ikhono layo lokujiya nokuzinzisa ukubunjwa kwe-adhesive liqinisekisa ukuthi lihlala lixutshwe ngokufanayo futhi kulula ukulisebenzisa. Emaphepheni nasekupakisheni okunamathelayo, i-HEC inikeza i-viscosity edingekayo yokusetshenziswa okufanele kanye namandla okubopha.
Izinamathiselo Zokwakha:
Ezinamathiselwe zokwakha, njengalezo ezisetshenziselwa ukufakwa kwamathayili noma ukumbozwa kodonga, i-HEC ithuthukisa i-viscosity, ithuthukise ukusebenza kwe-adhesive kanye nokumelana ne-sag. Isenzo sokuqina se-HEC siqinisekisa ukuthi i-adhesive ihlala endaweni ngesikhathi sokufaka isicelo futhi isetha kahle, inikeze isibopho esiqinile nesiqinile.
Izinamathiselo Zezimonyo Nokunakekela Umuntu:
I-HEC iphinde isetshenziswe emikhiqizweni yezimonyo neyomuntu siqu edinga izinto zokunamathela, njengamajeli esitayela sezinwele namamaski obuso. Kulezi zinhlelo zokusebenza, i-HEC inikeza ukungaguquguquki okushelelayo nokufanayo, okuthuthukisa ukusebenza komkhiqizo nolwazi lomsebenzisi.
Izinamathiselo Zemithi:
Embonini yezemithi, i-HEC isetshenziswa kuma-patches e-transdermal nakwezinye izinhlelo zokulethwa kwezidakamizwa lapho i-viscosity elawulwayo ibalulekile ekusebenzeni kokunamathela. I-HEC iqinisekisa ukuthi isendlalelo sokunamathisela siyafana, sinikeza ukulethwa kwezidakamizwa okungaguquki nokunamathela esikhumbeni.
Izinto Ezithinta Ukuthuthukiswa Kwe-Viscosity
Ukugxila:
Ukuhlushwa kwe-HEC ekwakhekeni kwe-adhesive kuhambisana ngokuqondile ne-viscosity. Ukugxila okuphezulu kwe-HEC kuphumela ekwandeni kwe-viscosity ngenxa yokuxhumana okubaluleke kakhulu kweketango le-polymer kanye nokubopha. Kodwa-ke, ukugxila okuphezulu ngokweqile kungaholela ku-gelation nobunzima bokucubungula.
Isisindo se-Molecular:
Isisindo samangqamuzana e-HEC siyisici esibalulekile ekunqumeni i-viscosity ye-adhesive. Isisindo samangqamuzana aphezulu i-HEC inikeza i-viscosity ephakeme ekugxilweni okuphansi uma kuqhathaniswa nokuhlukahluka okuphansi kwesisindo samangqamuzana. Ukukhethwa kwesisindo samangqamuzana kuncike ku-viscosity oyifunayo kanye nezidingo zohlelo lokusebenza.
Izinga lokushisa:
Izinga lokushisa lithinta i-viscosity yezixazululo ze-HEC. Njengoba izinga lokushisa likhuphuka, i-viscosity ngokuvamile iyehla ngenxa yokuncipha kwe-hydrogen bonding kanye nokwanda kokuhamba kwamangqamuzana. Ukuqonda ubudlelwano be-temperature-viscosity kubalulekile ezinhlelweni zokusebenza ezichayeke kumazinga okushisa ahlukahlukene.
i-pH:
I-pH yokwakhiwa kwe-adhesive ingathonya i-viscosity ye-HEC. I-HEC izinzile phezu kwebanga elibanzi le-pH, kodwa izimo ze-pH ezimbi kakhulu zingaholela ekushintsheni kwesakhiwo se-polymer kanye ne-viscosity. Ukwakha izinto ezinamathelayo ngaphakathi kwebanga le-pH elilungile kuqinisekisa ukusebenza okungaguquki.
Izinzuzo Zokusebenzisa I-Hydroxyethyl Cellulose
I-Non-Ionic Nature:
Imvelo engeyona i-ionic ye-HEC iyenza ihambisane nohlu olubanzi lwezinye izingxenye zokwakheka, okuhlanganisa namanye ama-polymer, ama-surfactants, nama-electrolyte. Lokhu kuhambisana kuvumela ukwakheka okunamathelayo okuhlukahlukene.
I-Biodegradability:
I-HEC isuselwa ku-cellulose, insiza yemvelo nevuselelekayo. Iyakwazi ukubola, okuyenza ibe ukukhetha okuvumela imvelo ukwakheka kokunamathelayo. Ukusetshenziswa kwayo kuhambisana nesidingo esikhulayo semikhiqizo esimeme ne-eco-friendly.
Ukuzinza:
I-HEC inikeza ukuzinza okuhle kakhulu ekwakhiweni kwe-adhesive, ukuvimbela ukuhlukaniswa kwesigaba kanye nokuxazulula izingxenye eziqinile. Lokhu kuzinza kuqinisekisa ukuthi i-adhesive ihlala isebenza kuyo yonke impilo yayo yeshalofu nangesikhathi sokufaka isicelo.
Izici Zokwenza Amafilimu:
I-HEC yenza amafilimu aguquguqukayo nasobala lapho omiswa, okuzuzisa izinhlelo zokunamathela ezidinga umugqa webhondi ocacile futhi oguquguqukayo. Lesi sakhiwo siwusizo ikakhulukazi ezinhlelweni ezinjengamalebula namateyipu.
I-Hydroxyethyl cellulose idlala indima ebalulekile ekwandiseni i-viscosity ye-adhesives ngokusebenzisa izindlela ezifana ne-hydration nokuvuvukala, ukubopha kwamangqamuzana, i-hydrogen bonding, kanye nokuziphatha kokunciphisa i-shear. Izakhiwo zayo, okuhlanganisa ukuncibilika, imvelo engeyona i-ionic, ukubola kwe-biodegradability, namandla okwenza ifilimu, kuyenza ibe inketho efanelekile yezinhlelo zokusebenza ezihlukahlukene zokunamathela. Ukuqonda izici ezithinta ukuthuthukiswa kwe-viscosity ye-HEC, njengokugxilisa ingqondo, isisindo samangqamuzana, izinga lokushisa, ne-pH, kuvumela abaqulunqi ukuthi bahlanganise imikhiqizo enamathelayo ukuze ihlangabezane nezimfuneko ezithile zokusebenza. Njengoba izimboni ziqhubeka nokufuna izinto ezisimeme nezisebenza kahle kakhulu, i-HEC isalokhu iyingxenye ebalulekile ekwakhiweni kwemikhiqizo enamathelayo esezingeni eliphezulu.
Isikhathi sokuthumela: May-29-2024