Hydroxyethyl cellulose (HEC) ke polima e se nang ionic, e qhibilihang ka metsing e tsoang ho selulose ka phetoho ea lik'hemik'hale. E fumana tšebeliso e pharaletseng liindastering tse fapaneng ka lebaka la thepa ea eona e ikhethang, joalo ka ho tenya, ho tsitsisa, le bokhoni ba ho etsa lifilimi. Lits'ebetsong moo botsitso ba pH bo leng bohlokoa, ho utloisisa hore na HEC e sebetsa joang tlas'a maemo a fapaneng a pH ho bohlokoa.
Ho tsitsa ha pH ea HEC ho bolela bokhoni ba eona ba ho boloka botsitso ba sebopeho, thepa ea rheological, le ts'ebetso ho pholletsa le mefuta e fapaneng ea maemo a pH. Botsitso bona bo bohlokoa lits'ebetsong tse joalo ka lihlahisoa tsa tlhokomelo ea motho, meriana, liphahlo le lisebelisoa tsa kaho, moo pH ea tikoloho e potolohileng e ka fapanang haholo.
Sebopeho:
HEC e atisa ho etsoa ka ho arabela selulose ka ethylene oxide tlas'a maemo a alkaline. Ts'ebetso ena e fella ka ho nkeloa sebaka ha lihlopha tsa hydroxyl tsa mokokotlo oa cellulose le lihlopha tsa hydroxyethyl (-OCH2CH2OH). The degree of substitution (DS) e bontsha palo e tlwaelehileng ya dihlopha tsa hydroxyethyl ka yuniti ya anhydroglucose ka hara ketane ya selulose.
Thepa:
Solubility: HEC e qhibiliha ka metsing 'me e etsa litharollo tse hlakileng, tse hlakileng.
Viscosity: E bonts'a boits'oaro ba pseudoplastic kapa chear-thinning, ho bolelang hore viscosity ea eona ea fokotseha tlasa khatello ea ho kuta. Thepa ena e etsa hore e be molemo lits'ebetsong moo phallo e leng bohlokoa, joalo ka lipente le lipente.
Thickening: HEC e fana ka viscosity ho tharollo, e etsa hore e be ea bohlokoa e le setsi se teteaneng mekhoeng e sa tšoaneng.
Ho etsa lifilimi: E ka etsa lifilimi tse feto-fetohang le tse pepeneneng ha li omisitsoe, tse nang le molemo lits'ebetsong tse kang likhomaretsi le likhoele.
pH botsitso ba HEC
Ho tsitsa ha pH ea HEC ho susumetsoa ke lintlha tse 'maloa, ho kenyelletsa le sebopeho sa lik'hemik'hale tsa polymer, litšebelisano le tikoloho e potolohileng, le li-additives leha e le life tse teng ha ho etsoa.
pH botsitso ba HEC ka mefuta e fapaneng ea pH:
1. pH e nang le asiti:
Ho acidic pH, HEC ka kakaretso e tsitsitse empa e ka ba le hydrolysis ka nako e telele tlasa maemo a thata a asiti. Leha ho le joalo, lits'ebetsong tse ngata tse sebetsang, tse kang lihlahisoa tsa tlhokomelo ea botho le liphahlo, moo pH ea acidic e kopanang le eona, HEC e lula e tsitsitse ka har'a mefuta e tloaelehileng ea pH (pH 3 ho 6). Ka ntle ho pH 3, kotsi ea hydrolysis ea eketseha, e lebisang ho fokotseha butle-butle ha viscosity le tshebetso. Ho bohlokoa ho beha leihlo pH ea metsoako e nang le HEC le ho e lokisa ha ho hlokahala ho boloka botsitso.
2. pH e sa nke lehlakore:
HEC e bontša botsitso bo babatsehang tlas'a maemo a sa nke lehlakore pH (pH 6 ho 8). Mofuta ona oa pH o tloaelehile lits'ebetsong tse ngata, ho kenyeletsoa litlolo, meriana le lihlahisoa tsa lapeng. Lihlahisoa tse nang le HEC li boloka viscosity ea tsona, thepa e teteaneng, le ts'ebetso e akaretsang ka har'a mofuta ona oa pH. Leha ho le joalo, lintlha tse kang mocheso le matla a ionic li ka susumetsa botsitso 'me li lokela ho nkoa nakong ea tsoelo-pele ea tlhahiso.
3. Alkaline pH:
HEC ha e tsitsitse tlas'a maemo a alkaline ha a bapisoa le pH ea acidic kapa e sa nke lehlakore. Maemong a phahameng a pH (ka holimo ho pH 8), HEC e ka 'na ea senyeha, e leng se bakang ho fokotseha ha viscosity le ho lahleheloa ke ts'ebetso. Alkaline hydrolysis ea likamano tsa ether pakeng tsa mokokotlo oa cellulose le lihlopha tsa hydroxyethyl li ka etsahala, tse lebisang ho scission ea ketane le ho fokotsa boima ba limolek'hule. Ka hona, ka metsoako ea alkaline e kang li-detergents kapa thepa ea kaho, li-polymers tse ling kapa li-stabilizer li ka khethoa ho feta HEC.
Lintlha tse Susumetsang pH botsitso
Lintlha tse 'maloa li ka susumetsa botsitso ba pH ba HEC:
Degree of Substitution (DS): HEC e nang le litekanyetso tse phahameng tsa DS e na le tšekamelo ea ho tsitsa ho feta mefuta e mengata ea pH ka lebaka la ho eketseha ha lihlopha tsa hydroxyl le lihlopha tsa hydroxyethyl, e leng se matlafatsang ho qhibiliha ha metsi le ho hanyetsa hydrolysis.
Mocheso: Mocheso o phahameng o ka potlakisa ts'ebetso ea lik'hemik'hale, ho kenyelletsa le hydrolysis. Ka hona, ho boloka mocheso o nepahetseng oa ho boloka le ho sebetsa ho bohlokoa bakeng sa ho boloka botsitso ba pH ba lihlahisoa tse nang le HEC.
Matla a Ionic: Matsoai a mangata kapa li-ion tse ling ha a etsoa a ka ama botsitso ba HEC ka ho ama ho qhibiliha ha eona le ho sebelisana le limolek'hule tsa metsi. Matla a ionic a lokela ho ntlafatsoa ho fokotsa litlamorao tse senyang.
Li-additives: Kenyelletso ea li-additives tse kang li-surfactants, li-preservatives, kapa li-buffering agents li ka ama botsitso ba pH ba lihlahisoa tsa HEC. Teko ea ho lumellana e lokela ho etsoa ho netefatsa tšebelisano e eketsehileng le botsitso.
Likopo le Mehopolo ea Tlhahiso
Ho utloisisa botsitso ba pH ba HEC ho bohlokoa haholo bakeng sa baetsi ba lihlahisoa liindastering tse fapaneng.
Mona ke lintlha tse ling tse amanang le ts'ebeliso:
Lihlahisoa tsa Tlhokomelo ea Botho: Ka li-shampoo, li-conditioner, le li-lotions, ho boloka pH ka har'a mefuta e lakatsehang (ka tloaelo ho pota-potile ho se nke lehlakore) ho tiisa botsitso le ts'ebetso ea HEC e le moemeli o teteaneng le o emisang.
Meriana ea Meriana: HEC e sebelisoa ho emisoa ka molomo, tharollo ea ophthalmic, le metsoako ea lihlooho. Lisebelisoa li lokela ho etsoa le ho bolokoa tlas'a maemo a bolokang botsitso ba HEC ho netefatsa katleho ea sehlahisoa le bophelo ba sethala.
Liaparo le Lipente: HEC e hiriloe e le rheology modifier le thickener lipenteng tse thehiloeng metsing le liphahlo. Baqapi ba tlameha ho leka-lekanya litlhoko tsa pH le mekhoa e meng ea ts'ebetso joalo ka viscosity, leveling, le sebopeho sa lifilimi.
Lisebelisoa tsa Kaho: Ha ho etsoa cementitious formulations, HEC e sebetsa e le moemeli oa ho boloka metsi le ho ntlafatsa ts'ebetso. Leha ho le joalo, maemo a alkaline ka samente a ka phephetsa botsitso ba HEC, ho hlokahala hore ho khethoe ka hloko le ho lokisa liphetoho.
Hydroxyethyl cellulose (HEC) e fana ka thepa ea bohlokoa ea rheological le e sebetsang lits'ebetsong tse fapaneng. Ho utloisisa botsitso ba pH ea eona ho bohlokoa bakeng sa baetsi ba lihlahisoa ho hlahisa litlolo tse tsitsitseng le tse sebetsang hantle. Le hoja HEC e bontša botsitso bo botle tlas'a maemo a pH a sa jeleng paate, ho lokela ho nahanoa ka maemo a acidic le alkaline ho thibela ho senyeha le ho netefatsa ts'ebetso e nepahetseng. Ka ho khetha kereiti e nepahetseng ea HEC, ho ntlafatsa litlhophiso tsa tlhahiso, le ho kenya ts'ebetsong maemo a loketseng a polokelo, baetsi ba lihlahisoa ba ka sebelisa melemo ea HEC ho pholletsa le libaka tse ngata tsa pH.
Nako ea poso: Mar-29-2024