I-ether ye-cellulose kwiimveliso ezisekelwe kwisamente

I-ether yeCellulose luhlobo lwezongezo ezisetyenziselwa izinto ezininzi ezinokusetyenziswa kwiimveliso zesamente. Eli phepha lizisa iimpawu zeekhemikhali ze-methyl cellulose (MC) kunye ne-hydroxypropyl methyl cellulose (HPMC /) esetyenziswa ngokuqhelekileyo kwiimveliso zesamente, indlela kunye nomgaqo wesisombululo senetha kunye neempawu eziphambili zesisombululo. Ukuncipha kobushushu bejeli ye-thermal kunye ne-viscosity kwiimveliso zesamente kwaxoxwa ngokusekelwe kumava asebenzayo okuvelisa.

Amagama angundoqo:i-cellulose ether; I-Methyl cellulose;I-Hydroxypropyl methyl cellulose; Ubushushu bejeli eshushu; i-viscosity

1. Isishwankathelo

I-Cellulose ether (i-CE ngokufutshane) yenziwe nge-cellulose ngokusebenzisa i-etherification reaction ye-etherifying agents ezininzi kunye nokusila okomileyo. I-CE inokwahlulwa ibe ziintlobo ze-ionic kunye ne-non-ionic, phakathi kwazo uhlobo lwe-CE olungeyo-ionic ngenxa yeempawu zayo ezikhethekileyo zejeli kunye nokunyibilika, ukuxhathisa ityuwa, ukumelana nobushushu, kwaye inomsebenzi ofanelekileyo womphezulu. Ingasetyenziswa njenge-arhente yokugcina amanzi, i-ejenti yokumiswa, i-emulsifier, i-agent eyenza ifilimu, i-lubricant, i-adhesive kunye ne-rheological improvement. Iindawo eziphambili zokusetyenziswa kwamanye amazwe ziingubo zelatex, izinto zokwakha, ukugaya ioli kunye nokunye. Xa kuthelekiswa namazwe angaphandle, ukuveliswa kunye nokusetyenziswa kwe-CE enyibilikayo emanzini kusekutsha. Ngophuculo lwempilo yabantu kunye nolwazi lokusingqongileyo. I-CE enyibilikayo emanzini, engenabungozi kwi-physiology kwaye ingangcolisi indalo, iya kuba nophuhliso olukhulu.

Kwintsimi yezinto zokwakha ngokuqhelekileyo i-CE ekhethiweyo yi-methyl cellulose (MC) kunye ne-hydroxypropyl methyl cellulose (HPMC), ingasetyenziselwa njengepeyinti, i-plaster, i-mortar kunye ne-samente iimveliso zeplastiki, i-viscosifier, i-agent yokugcinwa kwamanzi, i-agent yokungenisa umoya kunye ne-agent yokubuyisela. Uninzi loshishino lwezixhobo zokwakha lusetyenziswa kubushushu obuqhelekileyo, kusetyenziswa iimeko zomgubo womxube owomileyo kunye namanzi, ngaphantsi kokubandakanya iimpawu zokunyibilika kunye neempawu zejeli ezishushu ze-CE, kodwa kwimveliso yomatshini yeemveliso zesamente kunye nezinye iimeko zobushushu obukhethekileyo, ezi mpawu I-CE iya kudlala indima epheleleyo.

2. Iimpawu zeMichiza ye-CE

I-CE ifunyenwe ngokuphatha i-cellulose ngoluhlu lweendlela zekhemikhali kunye nezomzimba. Ngokutsho kwesakhiwo sokutshintshwa kweekhemikhali ezahlukeneyo, ngokuqhelekileyo sinokuhlulwa zibe: MC, HPMC, hydroxyethyl cellulose (HEC), njl. Kwinkqubo yokuvelisa i-CE, iifiber ze-cellulose ziqala ukufudumeza kwisisombululo se-alkali kwaye ziphathwe nge-etherifying agents. Iimveliso ze-fibrous reaction ziyahlanjululwa kwaye zihlulwe ukwenza umgubo ofanayo wokucolwa okuthile.

Inkqubo yemveliso ye-MC isebenzisa kuphela i-methane chloride njenge-agent etherifying. Ukongeza ekusebenziseni i-methane chloride, ukuveliswa kwe-HPMC kusebenzisa i-propylene oxide ukufumana amaqela e-hydroxypropyl substituent. Ezahlukeneyo ze-CE zinemilinganiselo eyahlukileyo ye-methyl kunye ne-hydroxypropyl, echaphazela ukuhambelana kwezinto eziphilayo kunye nobushushu bejeli ye-thermal yesisombululo se-CE.

Inani lamaqela oTshintsho kwi-dehydrated glucose structural units of cellulose inokubonakaliswa ngepesenti yobunzima okanye i-avareji yenani lamaqela okutshintsha (okt, DS - Degree of Substitution). Inani lamaqela abambeleyo limisela iimpawu zeemveliso zeCE. Isiphumo somndilili weqondo lokutshintshela ekunyibilikeni kweemveliso ze-etherification ngolu hlobo lulandelayo:

(1) iqondo eliphantsi lokutshintsha elinyibilikayo kwilye;

(2) iqondo eliphezulu kancinane endaweni enyibilikayo emanzini;

(3) iqondo eliphezulu lokutshintshela endaweni enyityilisiweyo kwizinyibilikisi ze-polar organic;

(4) Iqondo eliphezulu lokutshintshela endaweni echithwe kwi-solvents ye-organic non-polar.

3. Indlela yokuchithwa kwe-CE

I-CE inepropati ekhethekileyo ye-solubility, xa iqondo lokushisa liphakama kwiqondo elithile, alinakuncibilika emanzini, kodwa ngaphantsi kweli qondo lokushisa, ukunyibilika kwayo kuya kwanda ngokuhla kweqondo lokushisa. I-CE iyanyibilika emanzini abandayo (kwaye kwezinye iimeko kwii-solvents ezithile ze-organic) ngokusebenzisa inkqubo yokudumba kunye ne-hydration. Izisombululo ze-CE azinayo imida ecacileyo yokunyibilika okuvela ekunyibilikeni kweetyuwa ze-ionic. Ukugxininiswa kwe-CE ngokuqhelekileyo kunqunyelwe kwi-viscosity enokulawulwa sisixhobo sokuvelisa, kwaye iyahluka ngokwe-viscosity kunye neentlobo zeekhemikhali ezifunwa ngumsebenzisi. Isisombululo soxinaniso lwe-viscosity ephantsi ye-CE ngokubanzi yi-10% ~ 15%, kunye ne-viscosity ephezulu ye-CE ilinganiselwe kwi-2% ~ 3%. Iindidi ezahlukeneyo ze-CE (ezifana nomgubo okanye i-powder ephathwayo okanye i-granular) inokuchaphazela indlela isisombululo esilungiselelwe ngayo.

I-3.1 CE ngaphandle konyango olungaphezulu

Nangona i-CE inyibilika emanzini abandayo, kufuneka isasazwe ngokupheleleyo emanzini ukunqanda ukuhlangana. Kwezinye iimeko, umxube wesantya esiphezulu okanye ifanitshala unokusetyenziselwa amanzi abandayo ukusasaza umgubo we-CE. Nangona kunjalo, ukuba umgubo ongacocwanga wongezwa ngokuthe ngqo kumanzi abandayo ngaphandle kokuvuselela ngokwaneleyo, amaqhuma amaninzi ayakuvela. Isizathu esona sizathu sokwenza i-caking kukuba i-CE powder particles ayimanzi ngokupheleleyo. Xa kuphela inxalenye yepowder ichithwa, ifilimu ye-gel iya kwenziwa, ekhusela i-powder eseleyo ukuba iqhubeke nokuchithwa. Ke ngoko, ngaphambi kokuchithwa, amasuntswana e-CE kufuneka asasazwe ngokupheleleyo kangangoko kunokwenzeka. Ezi ndlela zimbini zilandelayo zokusasazwa ziqhele ukusetyenziswa.

3.1.1 Indlela yokusasazwa komxube owomileyo

Le ndlela isetyenziswa kakhulu kwiimveliso zesamente. Ngaphambi kokuba ungeze amanzi, xuba enye i powder kunye ne-CE powder ngokulinganayo, ukwenzela ukuba amasuntswana e-CE powder asasazwe. Ubuncinane bokuxuba umlinganiselo: Olunye umgubo: umgubo weCE =(3 ~ 7) : 1.

Ngale ndlela, ukusasazwa kwe-CE kugqitywe kwimeko eyomileyo, kusetyenziswa omnye umgubo njengophakathi ukusasaza amasuntswana e-CE omnye komnye, ukuze kuthintelwe ukudityaniswa kwamasuntswana e-CE xa ukongeza amanzi kunye nokuchaphazela ukunyibilika ngakumbi. Ngoko ke, amanzi ashushu akadingeki ukuba asasazeke, kodwa izinga lokuchithwa lixhomekeke kwiinqununu ze powder kunye neemeko eziphazamisayo.

3.1.2 Indlela yokusasazwa kwamanzi ashushu

(1) I-1/5 ~ 1/3 yokuqala yokufudumeza kwamanzi afunekayo ukuya kuma-90C ngaphezulu, yongeza i-CE, kwaye emva koko ugxobhoze de onke amasuntswana asasazwe abemanzi, kwaye ke amanzi aseleyo kumanzi abandayo okanye omkhenkce adityaniswe ukunciphisa ubushushu bomkhenkce. isisombululo, xa sele sifikelele kwiqondo lokushisa lokuchithwa kwe-CE, umgubo waqala ukumanzisa, i-viscosity yanda.

(2) Unako kwakhona ukufudumeza onke amanzi, uze wongeze CE ukushukumisa ngelixa ukupholisa de hydration kugqityiwe. Ukupholisa okwaneleyo kubaluleke kakhulu kwi-hydration epheleleyo ye-CE kunye nokwakhiwa kwe-viscosity. Ukufumana i-viscosity efanelekileyo, isisombululo se-MC kufuneka sipholiswe kwi-0 ~ 5 ℃, ngelixa i-HPMC ifuna ukupholiswa kuphela kwi-20 ~ 25 ℃ okanye ngaphantsi. Ekubeni i-hydration epheleleyo ifuna ukupholisa okwaneleyo, izisombululo ze-HPMC ziqhele ukusetyenziswa apho amanzi abandayo engenakusetyenziswa: ngokolwazi, i-HPMC inokunciphisa ubushushu obungaphantsi kwe-MC kumaqondo aphantsi ukuze ifikelele kwi-viscosity efanayo. Kuyafaneleka ukuba uqaphele ukuba indlela yokusasazwa kwamanzi ashushu yenza kuphela amasuntswana e-CE ahlakazeke ngokulinganayo kwiqondo lobushushu eliphezulu, kodwa akukho sisombululo sisenziwa ngeli xesha. Ukufumana isisombululo nge-viscosity ethile, kufuneka ipholile kwakhona.

3.2 Umphezulu onyangwa ngumgubo we-CE olahliweyo

Kwiimeko ezininzi, i-CE ifuneka ukuba ibe neempawu ezisasazekayo kunye nokukhawuleza kwe-hydration (ukwenza i-viscosity) kumanzi abandayo. Umphezulu ophathwe nge-CE awunyibiliki okwethutyana kumanzi abandayo emva konyango olukhethekileyo lwekhemikhali, oluqinisekisa ukuba xa i-CE ifakwe emanzini, ayisayi kudala i-viscosity ecacileyo kwaye inokusasazwa phantsi kweemeko ezincinci zokucheba. "Ixesha lokulibaziseka" le-hydration okanye i-viscosity formation sisiphumo sokudityaniswa kweqondo lonyango lomphezulu, ubushushu, i-pH yenkqubo, kunye noxinzelelo lwesisombululo se-CE. Ukulibaziseka kwe-hydration ngokuqhelekileyo kuncitshiswa kwiindawo eziphezulu, amaqondo obushushu, kunye namanqanaba e-pH. Ngokuqhelekileyo, nangona kunjalo, ukuxinwa kwe-CE akuqwalaselwa de ifike kwi-5% (umlinganiselo wobuninzi bamanzi).

Ukufumana iziphumo ezilungileyo kunye ne-hydration epheleleyo, indawo ephathwayo ye-CE kufuneka iqhutywe imizuzu embalwa phantsi kweemeko ezingathathi hlangothi, kunye ne-pH ukusuka kwi-8.5 ukuya kwi-9.0, de kube yi-viscosity ephezulu ifikeleleke (ngokuqhelekileyo i-10-30 imizuzu). Nje ukuba i-pH itshintshe kwisiseko (pH 8.5 ukuya ku-9.0), indawo ephathwayo ye-CE ichithwa ngokupheleleyo kwaye ngokukhawuleza, kwaye isisombululo sinokuzinza kwi-pH 3 ukuya kwe-11. Nangona kunjalo, kubalulekile ukuqaphela ukuba ukulungiswa kwe-pH ye-slurry yoxinaniso oluphezulu. iya kubangela ukuba i-viscosity ibe phezulu kakhulu ukupompa nokugalela. I-pH kufuneka ilungiswe emva kokuba i-slurry ihlanjululwe kwi-concentration oyifunayo.

Ukushwankathela, inkqubo yokuchithwa kwe-CE ibandakanya iinkqubo ezimbini: ukusasazeka ngokomzimba kunye nokuchithwa kweekhemikhali. Isitshixo kukusasaza amasuntswana e-CE omnye komnye ngaphambi kokuchithwa, ukuze kuthintelwe i-agglomeration ngenxa ye-viscosity ephezulu ngexesha lokuchithwa kobushushu obuphantsi, okuya kuchaphazela ukunyibilika ngakumbi.

4. Iipropati zesisombululo se-CE

Iindidi ezahlukeneyo ze-CE izisombululo ezinamanzi ziya kugeyiza kumaqondo obushushu azo athile. Ijeli iguqulwa ngokupheleleyo kwaye yenza isisombululo xa ipholile kwakhona. I-gelation ye-thermal eguqulwayo ye-CE iyingqayizivele. Kwiimveliso ezininzi zesamente, ukusetyenziswa okuphambili kwe-viscosity ye-CE kunye nokugcinwa kwamanzi okuhambelanayo kunye neempawu zokuthambisa, kunye ne-viscosity kunye nobushushu bejeli bunobudlelwane obuthe ngqo, phantsi kobushushu bejeli, ubushushu obuphantsi, ukuphakama kwe-viscosity ye-CE, ngcono ukugcinwa kwamanzi okuhambelana nokusebenza.

Inkcazo yangoku ye-gel phenomenon yile: kwinkqubo yokuchithwa, oku kuyafana.

Iimolekyuli ze-polymer zentambo zidibanisa kunye ne-molecular layer yamanzi, okubangela ukuvuvukala. Iimolekyuli zamanzi zisebenza njengeoli yokuthambisa, ekwazi ukutsala amatyathanga amade eemolekyuli zepolymer, ukuze isisombululo sibe neempawu ze-viscous fluid ekulula ukuyilahla. Xa ubushushu besisombululo sanda, i-polymer cellulose ngokuthe ngcembe ilahlekelwa ngamanzi kwaye i-viscosity yesisombululo iyancipha. Xa i-gel point ifikeleleke, i-polymer iyancipha ngokupheleleyo, okubangelwa ukudibanisa phakathi kweepolymers kunye nokubunjwa kwe-gel: amandla e-gel aqhubeka ekhula njengoko ubushushu buhlala ngaphezu kwendawo ye-gel.

Njengoko isisombululo sipholile, i-gel iqala ukuguquka kwaye i-viscosity iyancipha. Ekugqibeleni, i-viscosity yesisombululo sokupholisa ibuyela kwi-curve yokuqala yokunyuka kweqondo lokushisa kwaye inyuka ngokuhla kweqondo lokushisa. Isisombululo sinokupholiswa kwixabiso laso lokuqala le-viscosity. Ke ngoko, inkqubo ye-thermal gel ye-CE iyabuyiswa.

Indima ephambili ye-CE kwiimveliso zesamente ifana ne-viscosifier, i-plasticizer kunye ne-agent yokugcina amanzi, ngoko ke indlela yokulawula i-viscosity kunye nobushushu be-gel ibe yinto ebalulekileyo kwiimveliso ze-samente ngokuqhelekileyo zisebenzisa iqondo lokushisa lokuqala le-gel ngaphantsi kwecandelo le-curve. ngoko ke iqondo lobushushu lisezantsi, ukuphakama kwe-viscosity, kokukhona kucaca ngakumbi umphumo wokugcinwa kwamanzi e-viscosifier. Iziphumo zovavanyo lomgca wokuvelisa ibhodi yesamente ye-extrusion zikwabonisa ukuba ubushushu bezinto eziphathekayo buphantsi komxholo ofanayo we-CE, ngcono i-viscosification kunye nesiphumo sokugcinwa kwamanzi. Njengoko inkqubo yesamente iyinkqubo yepropathi entsonkothe ​​kakhulu yomzimba kunye neekhemikhali, zininzi izinto ezichaphazela utshintsho lobushushu bejeli ye-CE kunye ne-viscosity. Kwaye impembelelo yeendlela ezahlukeneyo zeTaianin kunye nesidanga azifani, ngoko ke isicelo esisebenzayo safumanisa ukuba emva kokuxuba inkqubo yesamente, iqondo lobushushu legel le-CE (oko kukuthi, ukuhla kweglu kunye nokugcinwa kwamanzi kubonakala kakhulu kobu bushushu. ) ziphantsi kweqondo lokushisa kwejel eliboniswe yimveliso, ngoko ke, ekukhethweni kweemveliso ze-CE ukuba zithathele ingqalelo izinto ezibangela ukwehla kobushushu be-gel. Ezi zilandelayo zizinto eziphambili esikholelwa ukuba zichaphazela i-viscosity kunye nobushushu bejel yesisombululo se-CE kwiimveliso zesamente.

4.1 Impembelelo yexabiso le-pH kwi-viscosity

I-MC kunye ne-HPMC ayinayo i-ionic, ngoko i-viscosity yesisombululo kune-viscosity ye-ionic glue yendalo inoluhlu olubanzi lwe-DH ukuzinza, kodwa ukuba ixabiso le-pH lidlula uluhlu lwe-3 ~ 11, baya kunciphisa ngokuthe ngcembe i-viscosity kwindawo. ukushisa okuphezulu okanye kwindawo yokugcina ixesha elide, ngokukodwa isisombululo esiphezulu se-viscosity. I-viscosity yesisombululo semveliso ye-CE iyancipha kwi-asidi eyomeleleyo okanye isisombululo esisisiseko esinamandla, esibangelwa ikakhulu kukuphelelwa ngamanzi emzimbeni we-CE okubangelwa yisiseko kunye ne-asidi. Ke ngoko, i-viscosity ye-CE ihlala iyancipha ukuya kuthi ga kwinqanaba elithile kwindawo yealkaline yeemveliso zesamente.

4.2 Impembelelo yomlinganiselo wokufudumeza kunye nokuvuselela kwinkqubo yejeli

Ubushushu beqondo le-gel buya kuchaphazeleka ngumphumo odibeneyo wokufudumeza izinga kunye nokuvuselela izinga lokucheba. Ukuvuselela isantya esiphezulu kunye nokufudumeza ngokukhawuleza kuya kwandisa kakhulu ubushushu bejeli, obulungele iimveliso zesamente ezenziwe ngokuxuba oomatshini.

4.3 Impembelelo yoxinzelelo kwijeli eshushu

Ukwandisa ukuxinana kwesisombululo kudla ngokuthoba ubushushu bejeli, kwaye amanqaku ejeli e-CE ephantsi angaphezulu kune-viscosity ephezulu ye-CE. Ezinje nge-DOW's METHOCEL A

Ubushushu bejeli buya kuncitshiswa nge-10 ℃ kuzo zonke iipesenti ezi-2 zokunyuka koxinzelelo lwemveliso. Ukunyuka kwe-2% kugxininiso lweemveliso zohlobo lwe-F kuya kunciphisa ubushushu bejeli nge-4℃.

4.4 Impembelelo yezongezo kwi-thermal gelation

Kwintsimi yezinto zokwakha, izinto ezininzi ziyi-salts ze-inorganic, eziza kuba nefuthe elibalulekileyo kwiqondo lokushisa le-gel yesisombululo se-CE. Kuxhomekeka ekubeni isongezelelo sisebenza njenge-coagulant okanye i-solubilizing agent, ezinye izongezo zinokunyusa ubushushu bejeli ye-thermal ye-CE, ngelixa ezinye zinokunciphisa ubushushu bejeli ye-CE: umzekelo, i-ethanol yokuphucula i-solvent, i-PEG-400 (ipolyethylene glycol) , i-anediol, njl., inokunyusa i-gel point. Iityuwa, i-glycerin, i-sorbitol kunye nezinye izinto ziya kunciphisa i-gel point, i-non-ionic CE ngokubanzi ayiyi kuncitshiswa ngenxa ye-ion yensimbi ye-polyvalent, kodwa xa ugxininiso lwe-electrolyte okanye ezinye izinto ezinyibilikisiweyo zidlula umda othile, iimveliso ze-CE zinokugalelwa ngaphandle. isisombululo, oku kungenxa yokhuphiswano lwe-electrolytes emanzini, okukhokelela ekucuthweni kwe-hydration ye-CE, Umxholo wetyuwa wesisombululo semveliso ye-CE uphezulu kancinane kunemveliso yeMc, kwaye umxholo wetyuwa wahluke kancinane. kwii-HPMC ezahlukeneyo.

Izithako ezininzi kwiimveliso zesamente ziya kwenza i-gel point ye-CE yehla, ngoko ke ukhetho lwezongezo kufuneka luthathele ingqalelo ukuba oku kunokubangela ukuba i-gel point kunye ne-viscosity ye-CE itshintshe.

5.Isiphelo

(1) i-cellulose ether yi-cellulose yendalo ngokusabela kwe-etherification, ineyunithi esisiseko yesakhiwo se-glucose dehydrated, ngokohlobo kunye nenani lamaqela athatha indawo kwindawo yayo yokutshintshwa kwaye ineempawu ezahlukeneyo. I-ether engeyiyo i-ionic efana ne-MC kunye ne-HPMC ingasetyenziselwa i-viscosifier, i-ejenti yokugcina amanzi, i-agent yokungenisa umoya kunye nezinye ezisetyenziswa ngokubanzi kwimveliso yezinto zokwakha.

(2) I-CE ine-solubility ekhethekileyo, isenza isisombululo kwiqondo elithile lobushushu (elifana nobushushu be-gel), kunye nokwenza i-gel eqinile okanye umxube oqinileyo we-particle kwiqondo lokushisa. Iindlela eziphambili zokuchithwa yindlela yokuxuba ukuxuba okomileyo, indlela yokusasazwa kwamanzi ashushu, njl. Isitshixo kukusasaza i-CE ngokulinganayo ngaphambi kokuba inyibilike, yenze isisombululo kumaqondo obushushu aphantsi.

3 , kuzisa imiphumo emibi. Ngoko ke, ngokweempawu ze-CE, okokuqala, kufuneka isetyenziswe kwiqondo lokushisa eliphantsi (ngaphantsi kweqondo lokushisa le-gel), kwaye okwesibini, impembelelo yezongezo kufuneka ithathelwe ingqalelo.