I-cellulose ether emikhiqizweni esekwe usimende

I-Cellulose ether iwuhlobo lwezithako ezinemisebenzi eminingi ezingasetshenziswa emikhiqizweni kasimende. Leli phepha lethula izakhiwo zamakhemikhali ze-methyl cellulose (MC) kanye ne-hydroxypropyl methyl cellulose (HPMC /) evame ukusetshenziswa emikhiqizweni kasimende, indlela kanye nomgomo wesixazululo senetha kanye nezici eziyinhloko zesisombululo. Ukwehla kwezinga lokushisa lejeli elishisayo kanye ne-viscosity emikhiqizweni kasimende kwaxoxwa ngakho ngokusekelwe ekuhlangenwe nakho okungokoqobo kokukhiqiza.

Amagama angukhiye:i-cellulose ether; I-methyl cellulose;I-Hydroxypropyl methyl cellulose; Ijeli lokushisa elishisayo; i-viscosity

1. Uhlolojikelele

I-Cellulose ether (i-CE ngamafuphi) yenziwe nge-cellulose ngokusabela kwe-etherification kwe-ejenti etherifying eyodwa noma amaningana kanye nokugaya okomile. I-CE ingahlukaniswa ngezinhlobo ze-ionic nezingezona i-ionic, phakathi kwazo uhlobo olungezona i-ionic i-CE ngenxa yezimpawu zayo ezihlukile zejeli ezishisayo nokuncibilika, ukumelana nosawoti, ukumelana nokushisa, futhi inomsebenzi ofanele ongaphezulu. Ingasetshenziswa njenge-ejenti yokugcina amanzi, i-ejenti yokumiswa, i-emulsifier, i-ejenti yokwakha ifilimu, i-lubricant, i-adhesive kanye nesithuthukisi se-rheological. Izindawo ezisetshenziswa kakhulu kwamanye amazwe yizingubo ze-latex, izinto zokwakha, ukumba uwoyela nokunye. Uma kuqhathaniswa namazwe angaphandle, ukukhiqizwa nokusebenzisa i-CE encibilikayo emanzini kuseyinsakavukela. Ngokuthuthukiswa kokuqwashisa ngempilo yabantu kanye nemvelo. I-CE encibilikayo emanzini, engenabungozi ku-physiology futhi engangcolisi imvelo, izoba nentuthuko enkulu.

Emkhakheni wezinto zokwakha ezivame ukukhethwa i-CE i-methyl cellulose (MC) kanye ne-hydroxypropyl methyl cellulose (HPMC), ingasetshenziswa njengopende, ukhonkolo, udaka kanye nemikhiqizo kasimende, ipulasitiki, i-viscosifier, i-ejenti yokugcina amanzi, i-ejenti yokungenisa umoya kanye ne-ejenti ebambezela isikhathi. Iningi lemboni yezinto zokwakha lisetshenziswa ekushiseni okujwayelekile, kusetshenziswa izimo yimpushana eyomile namanzi, engaphansi kwezimpawu zokuhlakazeka kanye nezici zejeli ezishisayo ze-CE, kepha ekukhiqizeni ngomshini imikhiqizo usimende nezinye izimo zokushisa ezikhethekile, lezi zici I-CE izodlala indima egcwele kakhulu.

2. Izici zamakhemikhali ze-CE

I-CE itholakala ngokwelapha i-cellulose ngochungechunge lwezindlela zamakhemikhali nezomzimba. Ngokwesakhiwo esihlukile sokushintsha amakhemikhali, imvamisa ingahlukaniswa kube: MC, HPMC, hydroxyethyl cellulose (HEC), njll. : I-CE ngayinye inesakhiwo esiyisisekelo se-cellulose - i-glucose engenamanzi. Enqubweni yokukhiqiza i-CE, imicu ye-cellulose iqala ukushiswa ngesisombululo se-alkaline bese iphathwa nge-etherifying agents. Imikhiqizo yokusabela kwe-fibrous iyahlanzwa futhi igaywe ukuze yakhe impushana efanayo yokucoleka okuthile.

Inqubo yokukhiqiza ye-MC isebenzisa kuphela i-methane chloride njenge-ejenti e-etherifying. Ngaphezu kokusetshenziswa kwe-methane chloride, ukukhiqizwa kwe-HPMC kusebenzisa i-propylene oxide ukuthola amaqembu angena esikhundleni se-hydroxypropyl. I-CE ehlukahlukene inamazinga ahlukile wokushintsha i-methyl ne-hydroxypropyl, athinta ukuhambisana kwezinto eziphilayo kanye nezinga lokushisa elishisayo lejeli lesixazululo se-CE.

Inani lamaqembu Okushintshana kumayunithi esakhiwo se-glucose ephelelwe amanzi emzimbeni we-cellulose lingavezwa ngephesenti lesisindo noma inani elimaphakathi lamaqembu okushintsha (okungukuthi, DS - Degree of Substitution). Inani lamaqembu angena esikhundleni linquma izakhiwo zemikhiqizo ye-CE. Umthelela wezinga elimaphakathi lokushintsha ekuncibilikeni kwemikhiqizo ye-etherification umi kanje:

(1) izinga eliphansi lokushintsha elincibilika ku-lye;

(2) izinga eliphezulu kancane lokuncibilika emanzini;

(3) izinga eliphezulu lokushintsha elincibilikisiwe kuzincibilikisi ze-polar organic;

(4) Izinga eliphakeme lokushintsha elincibilikisiwe kuzincibilikisi ze-organic non-polar.

3. Indlela yokuchithwa ye-CE

I-CE inendawo eyingqayizivele ye-solubility, lapho izinga lokushisa likhuphukela ekushiseni okuthile, alincibiliki emanzini, kodwa ngaphansi kwalokhu kushisa, ukuncibilika kwayo kuzokwanda ngokuncipha kwezinga lokushisa. I-CE iyancibilika emanzini abandayo (futhi kwezinye izimo kuma-solvents athile e-organic) ngenqubo yokuvuvukala kanye ne-hydration. Izixazululo ze-CE azinayo imikhawulo ecacile yokuncibilika evela ekuhlakazweni kosawoti we-ionic. Ukuhlushwa kwe-CE ngokuvamile kukhawulelwe ku-viscosity engalawulwa yimishini yokukhiqiza, futhi kuyahlukahluka ngokuya nge-viscosity nezinhlobonhlobo zamakhemikhali ezidingwa ngumsebenzisi. Isixazululo se-viscosity ephansi ye-CE ngokuvamile siyi-10% ~ 15%, futhi i-viscosity ephezulu ye-CE ngokuvamile ikhawulelwe ku-2% ~ 3%. Izinhlobo ezahlukene ze-CE (ezifana nempushana noma impushana ephathwayo noma i-granular) zingathinta indlela isixazululo esilungiswa ngayo.

3.1 CE ngaphandle kokwelashwa okungaphezulu

Nakuba i-CE inyibilika emanzini abandayo, kufanele ihlakazwe ngokuphelele emanzini ukugwema ukunqwabelana. Kwezinye izimo, i-mixer yesivinini esiphezulu noma ifaneli ingasetshenziswa emanzini abandayo ukuze kuhlakazwe impushana ye-CE. Kodwa-ke, uma impushana enganakiwe ifakwa ngqo emanzini abandayo ngaphandle kokunyakaziswa ngokwanele, kuzoba nezigaxa ezinkulu. Isizathu esiyinhloko se-caking ukuthi izinhlayiya ze-CE powder azimanzi ngokuphelele. Uma kuphela ingxenye ye-powder ichitheka, ifilimu ye-gel izokwakhiwa, evimbela i-powder esele ukuthi iqhubeke nokuncibilika. Ngakho-ke, ngaphambi kokuhlakazwa, izinhlayiya ze-CE kufanele zihlakazwe ngokugcwele ngangokunokwenzeka. Izindlela ezimbili ezilandelayo zokusabalalisa zivame ukusetshenziswa.

3.1.1 Indlela yokusabalalisa ingxube eyomile

Le ndlela isetshenziswa kakhulu emikhiqizweni kasimende. Ngaphambi kokungeza amanzi, hlanganisa enye impushana ne-CE powder ngokulinganayo, ukuze izinhlayiya ze-CE powder zihlakazwe. Isilinganiso esincane sokuxuba: Enye impushana: Impushana ye-CE =(3 ~ 7): 1.

Ngale ndlela, ukuhlakazwa kwe-CE kuqedwa esimweni esomile, kusetshenziswa enye impushana njengendawo yokusabalalisa izinhlayiya ze-CE komunye nomunye, ukuze kugwenywe ukuhlangana kwezinhlayiya ze-CE lapho wengeza amanzi futhi kuthinte ukuhlakazeka okwengeziwe. Ngakho-ke, amanzi ashisayo awadingeki ekuhlakazweni, kodwa izinga lokuhlakazeka lincike ezinhlayiyeni zempushana kanye nezimo ezinyakazayo.

3.1.2 Indlela yokusabalalisa amanzi ashisayo

(1) I-1/5 ~ 1/3 yokuqala yokushisisa kwamanzi edingekayo ibe ngu-90C ngaphezulu, engeza i-CE, bese ugoqa kuze kube yilapho zonke izinhlayiya zihlakazeka ziba manzi, bese amanzi asele emanzini abandayo noma eqhwa engezwa ukunciphisa izinga lokushisa. isixazululo, lapho sesifinyelele izinga lokushisa lokuqedwa kwe-CE, impushana yaqala ukumanzisa, i-viscosity yanda.

(2) Ungakwazi futhi ukufudumeza wonke amanzi, bese wengeza i-CE ukuze ugovuze ngenkathi upholisa kuze kuphele ukugeleza kwamanzi. Ukupholisa okwanele kubaluleke kakhulu ku-hydration ephelele ye-CE kanye nokwakhiwa kwe-viscosity. Ukuze uthole i-viscosity ekahle, isisombululo se-MC kufanele sipholiswe sibe ngu-0 ~ 5℃, kuyilapho i-HPMC idinga kuphela ukupholiswa ku-20~ 25℃ noma ngaphansi. Njengoba i-hydration ephelele idinga ukupholisa okwanele, izixazululo ze-HPMC zivame ukusetshenziswa lapho amanzi abandayo engakwazi ukusetshenziswa khona: ngokolwazi, i-HPMC inokunciphisa izinga lokushisa elincane kune-MC emazingeni okushisa aphansi ukuze kuzuzwe i-viscosity efanayo. Kuyaphawuleka ukuthi indlela yokusabalalisa amanzi ashisayo yenza kuphela izinhlayiya ze-CE zihlakazeke ngokulinganayo ekushiseni okuphezulu, kodwa asikho isisombululo esakhiwayo ngalesi sikhathi. Ukuze uthole isixazululo nge-viscosity ethile, kufanele ipholile futhi.

3.2 Impushana ye-CE ephathwayo ephathwayo

Ezimweni eziningi, i-CE idingeka ukuthi ibe nezici zombili ezihlakazekayo nezisheshayo ze-hydration (ukwenza i-viscosity) emanzini abandayo. I-Surface ephathwayo ye-CE ayincibiliki okwesikhashana emanzini abandayo ngemuva kokwelashwa kwamakhemikhali okukhethekile, okuqinisekisa ukuthi lapho i-CE yengezwa emanzini, ngeke ivele yakhe i-viscosity esobala futhi ingahlakazwa ngaphansi kwezimo ze-shear force encane. "Isikhathi sokubambezeleka" sokwakheka kwe-hydration noma i-viscosity siwumphumela wenhlanganisela yezinga lokwelashwa kwendawo, izinga lokushisa, i-pH yohlelo, kanye nokugxilwa kwesisombululo se-CE. Ukubambezeleka kwe-hydration kuvame ukuncishiswa ekugxilweni okuphezulu, amazinga okushisa, namazinga e-pH. Nokho, ngokuvamile, ukuhlushwa kwe-CE akucatshangwa kuze kube yilapho kufinyelela ku-5% (isilinganiso esikhulu samanzi).

Ukuze uthole imiphumela engcono kakhulu kanye ne-hydration ephelele, indawo ephathwayo ye-CE kufanele inyakaziswe imizuzu embalwa ngaphansi kwezimo ezingathathi hlangothi, nebanga le-pH lisuka ku-8.5 liye ku-9.0, kuze kube yilapho kufinyelelwa i-viscosity ephezulu (imvamisa imizuzu eyi-10-30). Uma i-pH ishintshela kusisekelo (pH 8.5 kuya ku-9.0), indawo ephathwayo ye-CE incibilika ngokuphelele futhi ngokushesha, futhi isisombululo singazinza ku-pH 3 kuya ku-11. Nokho, kubalulekile ukuqaphela ukuthi ukulungisa i-pH ye-slurry ephezulu yokugxila. kuzobangela ukuthi i-viscosity ibe phezulu kakhulu ukupompa nokuthulula. I-pH kufanele ilungiswe ngemva kokuba i-slurry ihlanjululwe ekugxilweni okufunayo.

Ukufingqa, inqubo yokuhlakaza ye-CE ifaka izinqubo ezimbili: ukuhlakazeka ngokomzimba kanye nokuqedwa kwamakhemikhali. Isihluthulelo siwukuhlakaza izinhlayiya ze-CE nomunye ngaphambi kokuhlakazwa, ukuze ugweme ukuhlangana ngenxa ye-viscosity ephezulu ngesikhathi sokuncibilika kwezinga lokushisa eliphansi, okuzothinta ukuhlakazeka okwengeziwe.

4. Izakhiwo zesixazululo se-CE

Izinhlobo ezahlukene zezixazululo ze-CE ezinamanzi zizogeleza emazingeni azo okushisa athile. Ijeli ibuyiselwa emuva ngokuphelele futhi yenza isixazululo lapho ipholile futhi. I-gelation eshintshayo ye-thermal ye-CE ihlukile. Emikhiqizweni eminingi kasimende, ukusetshenziswa okuyinhloko kwe-viscosity ye-CE kanye nokugcinwa kwamanzi okuhambisanayo kanye nezindawo zokugcoba, kanye ne-viscosity kanye nokushisa kwejeli kunobudlelwane obuqondile, ngaphansi kokushisa kwejeli, ukwehla kwezinga lokushisa, ukuphakama kwe-viscosity ye-CE, ngcono ukusebenza okuhambisanayo kokugcinwa kwamanzi.

Incazelo yamanje yesenzo sejeli yilena: ngesikhathi sokuhlakazwa, lokhu kuyafana.

Ama-molecule e-polymer ochungechunge axhuma nongqimba lwamangqamuzana lamanzi, okuholela ekuvuvukeni. Amangqamuzana amanzi asebenza njengowoyela wokugcoba, ongahlukanisa amaketanga amade ama-molecule e-polymer, ukuze ikhambi libe nezakhi zoketshezi lwe-viscous okulula ukululahla. Lapho izinga lokushisa lesisombululo landa, i-polymer cellulose kancane kancane ilahlekelwa amanzi futhi i-viscosity yesisombululo iyancipha. Lapho iphuzu le-gel lifinyelelwa, i-polymer iphelelwa amanzi ngokuphelele, okuholela ekuxhumaneni phakathi kwama-polymers kanye nokwakheka kwejeli: amandla ejeli aqhubeka nokwanda njengoba izinga lokushisa lihlala ngaphezu kwephuzu le-gel.

Njengoba isisombululo sipholile, ijeli iqala ukuhlehla futhi i-viscosity iyancipha. Ekugcineni, i-viscosity yesisombululo sokupholisa ibuyela ejikeni lokuqala lokwenyuka kwezinga lokushisa futhi iyanda ngokuncipha kwezinga lokushisa. Isixazululo singapholiswa sibe yinani laso lokuqala le-viscosity. Ngakho-ke, inqubo yejeli eshisayo ye-CE iyabuyiselwa emuva.

Indima eyinhloko ye-CE emikhiqizweni kasimende injenge-viscosifier, i-plasticizer kanye ne-ejenti yokugcina amanzi, ngakho-ke indlela yokulawula i-viscosity kanye nokushisa kwejeli sekuyinto ebalulekile emikhiqizweni kasimende ngokuvamile isebenzisa iphuzu layo lokuqala lokushisa lejeli ngaphansi kwesigaba sejika, ngakho-ke ukwehla kwezinga lokushisa, ukuphakama kwe-viscosity, umphumela osobala kakhulu wokugcinwa kwamanzi we-viscosifier. Imiphumela yokuhlolwa yolayini wokukhiqiza webhodi likasimende we-extrusion iphinde ibonise ukuthi ukwehla kwezinga lokushisa lempahla lingaphansi kokuqukethwe okufanayo kwe-CE, kuba ngcono umphumela we-viscosification nokugcinwa kwamanzi. Njengoba uhlelo lukasimende luwuhlelo oluyinkimbinkimbi kakhulu lwempahla yomzimba namakhemikhali, kunezici eziningi ezithinta ukuguqulwa kwezinga lokushisa lejeli le-CE kanye ne-viscosity. Futhi umthelela wokuthambekela okuhlukahlukene kwe-Taianin kanye neziqu azifani, ngakho-ke ukusetshenziswa okusebenzayo kuphinde kwathola ukuthi ngemva kokuxuba uhlelo lukasimende, izinga lokushisa langempela lejeli le-CE (okungukuthi, ukwehla komphumela weglue nokugcinwa kwamanzi kubonakala kakhulu kulokhu kushisa. ) zingaphansi kwezinga lokushisa lejeli elikhonjiswe ngumkhiqizo, ngakho-ke, ekukhethweni kwemikhiqizo ye-CE ukucabangela izici ezibangela ukwehla kwezinga lokushisa kwejeli. Okulandelayo yizici eziyinhloko esikholelwa ukuthi zithinta i-viscosity nezinga lokushisa lejeli lesixazululo se-CE emikhiqizweni kasimende.

4.1 Umthelela yenani le-pH ku-viscosity

I-MC ne-HPMC akuzona i-ionic, ngakho-ke i-viscosity yesisombululo kune-viscosity yeglue ye-ionic yemvelo inohlu olubanzi lokuzinza kwe-DH, kodwa uma inani le-pH lidlula ububanzi obungu-3 ~ 11, kancane kancane bazonciphisa i-viscosity endaweni izinga lokushisa eliphakeme noma endaweni yokugcina isikhathi eside, ikakhulukazi isisombululo se-viscosity ephezulu. I-viscosity yesisombululo somkhiqizo we-CE yehla ku-asidi eqinile noma isixazululo esiyisisekelo esiqinile, okubangelwa ikakhulukazi ukuphelelwa amanzi emzimbeni kwe-CE okubangelwa isisekelo ne-asidi. Ngakho-ke, i-viscosity ye-CE imvamisa yehla ngezinga elithile endaweni ene-alkali yemikhiqizo kasimende.

4.2 Umthelela wezinga lokushisa nokunyakaziswa kwenqubo yejeli

Izinga lokushisa le-gel point lizothinteka ngomphumela ohlangene wezinga lokushisa kanye nesilinganiso sokushefa esishukumisayo. Ukunyakazisa isivinini esikhulu kanye nokushisa okusheshayo ngokuvamile kuzokhuphula izinga lokushisa lejeli ngokuphawulekayo, elilungele imikhiqizo kasimende eyakhiwe ngokuxutshwa ngomshini.

4.3 Umthelela wokugxilisa ingqondo kujeli eshisayo

Ukwandisa ukugxila kwesixazululo kuvame ukwehlisa izinga lokushisa lejeli, futhi amaphuzu ejeli e-viscosity ephansi ye-CE aphakeme kunalawo e-viscosity ephezulu ye-CE. Okufana ne-DOW's METHOCEL A

Izinga lokushisa lejeli lizoncishiswa ngo-10℃ kukho konke ukukhuphuka okungu-2% ekugxilweni komkhiqizo. Ukwenyuka ngo-2% ekugxilweni kwemikhiqizo yohlobo luka-F kuzonciphisa izinga lokushisa lejeli ngo-4℃.

4.4 Ithonya lezithasiselo ku-thermal gelation

Emkhakheni wezinto zokwakha, izinto eziningi ziwusawoti we-inorganic, ozoba nomthelela omkhulu ekushiseni kwejeli yesixazululo se-CE. Kuya ngokuthi isithasiselo sisebenza njenge-coagulant noma i-solubilizing agent, ezinye izithasiselo zingakhuphula izinga lokushisa lejeli elishisayo le-CE, kanti ezinye zinganciphisa izinga lokushisa lejeli elishisayo le-CE: isibonelo, i-ethanol ethuthukisa i-solvent, PEG-400(polyethylene glycol) , i-anediol, njll., ingakhuphula iphuzu le-gel. Usawoti, i-glycerin, i-sorbitol nezinye izinto zizonciphisa iphuzu lejeli, i-non-ionic CE ngokuvamile ngeke idonswe ngenxa yama-ion ensimbi e-polyvalent, kodwa lapho ukuhlushwa kwe-electrolyte noma ezinye izinto ezincibilikisiwe zidlula umkhawulo othile, imikhiqizo ye-CE ingafakwa usawoti ngaphandle. Isixazululo, lokhu kungenxa yokuncintisana kwama-electrolyte emanzini, okuholela ekuncishisweni kwe-hydration ye-CE, Okuqukethwe kukasawoti wesixazululo somkhiqizo we-CE ngokuvamile kuphakeme kancane kunomkhiqizo we-Mc, futhi okuqukethwe kukasawoti kuhluke kancane. ku-HPMC ehlukene.

Izithako eziningi emikhiqizweni kasimende zizokwenza iphuzu lejeli le-CE lehle, ngakho-ke ukukhethwa kwezithasiselo kufanele kucabangele ukuthi lokhu kungabangela iphuzu lejeli kanye ne-viscosity yezinguquko ze-CE.

5.Isiphetho

(1) i-cellulose ether iyi-cellulose yemvelo ngokusabela kwe-etherification, ineyunithi yesakhiwo eyisisekelo ye-glucose ephelelwe amanzi, ngokuya ngohlobo nenani lamaqembu abambele endaweni yawo futhi inezici ezihlukile. I-ether engeyona i-ionic efana ne-MC ne-HPMC ingasetshenziswa njenge-viscosifier, i-ejenti yokugcinwa kwamanzi, i-ejenti yokungenisa umoya nokunye okusetshenziswa kakhulu emikhiqizweni yezinto zokwakha.

(2) I-CE ine-solubility eyingqayizivele, yenza isixazululo ezingeni lokushisa elithile (njengejeli lokushisa), futhi yakhe ijeli eqinile noma ingxube yezinhlayiyana eziqinile ekushiseni kwejeli. Izindlela eziyinhloko zokuhlakaza indlela yokuhlakaza okuxutshwa okomile, indlela yokusabalalisa amanzi ashisayo, njll., emikhiqizweni kasimende evame ukusetshenziswa indlela yokuhlakaza okomile. Okubalulekile wukusabalalisa i-CE ngokulinganayo ngaphambi kokuthi incibilike, yenze isisombululo emazingeni okushisa aphansi.

(3) Isixazululo sokuhlushwa, izinga lokushisa, inani le-pH, izakhiwo zamakhemikhali zezithasiselo kanye nezinga elinyakazayo lizothinta izinga lokushisa lejeli kanye ne-viscosity yesisombululo se-CE, ikakhulukazi imikhiqizo kasimende iyizixazululo zikasawoti we-inorganic endaweni ene-alkali, ngokuvamile inciphisa izinga lokushisa lejeli kanye ne-viscosity yesisombululo se-CE. , okuletha imiphumela emibi. Ngakho-ke, ngokwezici ze-CE, okokuqala, kufanele isetshenziswe ekushiseni okuphansi (ngaphansi kokushisa kwe-gel), futhi okwesibili, ithonya lezithasiselo kufanele licatshangelwe.