Focus on Cellulose ethers

Ukuqina kanye Thixotropy yeCellulose Ether

Ukuqina komphumela we-cellulose ether kuncike: izinga le-polymerization ye-cellulose ether, ukuhlushwa kwesisombululo, izinga le-shear, izinga lokushisa nezinye izimo. Impahla ye-gelling yesisombululo iyimpahla ye-alkyl cellulose kanye nokuphuma kwayo okuguquliwe. Izakhiwo ze-gelation zihlobene nezinga lokushintshwa, ukugxila kwesisombululo kanye nezithasiselo. Kokuphuma kokunye okuguquliwe kwe-hydroxyalkyl, izakhiwo zejeli nazo zihlobene nezinga lokuguqulwa le-hydroxyalkyl. Ukuze uthole i-viscosity ephansi ye-MC ne-HPMC, isisombululo se-10% -15% singalungiswa, i-viscosity ephakathi kwe-MC ne-HPMC ingalungiswa isixazululo esingu-5% -10%, kuyilapho i-viscosity ephezulu ye-MC ne-HPMC ingalungisa kuphela isixazululo esingu-2% -3%, futhi Ngokuvamile ukuhlukaniswa kwe-viscosity ye-cellulose ether nayo ihlelwe ngesisombululo se-1% -2%.

I-high molecular weight cellulose ether ine-high thickening ukusebenza kahle. Esixazululweni esifanayo sokuhlushwa, ama-polymer anesisindo samangqamuzana ahlukene anama-viscosity ahlukene. Izinga eliphezulu. I-viscosity ehlosiwe ingafinyelelwa kuphela ngokungeza inani elikhulu lesisindo esiphansi se-cellulose ether. I-viscosity yayo inokwencika okuncane kuzinga lokugunda, futhi i-viscosity ephezulu ifinyelela i-viscosity ehlosiwe, futhi inani elidingekayo lokwengeza lincane, futhi i-viscosity incike ekusebenzeni kahle kokuqina. Ngakho-ke, ukuze kuzuzwe ukuvumelana okuthile, inani elithile le-cellulose ether (ukugxila kwesisombululo) kanye ne-viscosity yesisombululo kufanele kuqinisekiswe. Izinga lokushisa lejeli lesisombululo liphinde linciphise ngokuhambisana nokwanda kokuhlushwa kwesisombululo, nama-gel ekamelweni lokushisa ngemva kokufinyelela ekugxilweni okuthile. I-concentration ye-gelling ye-HPMC iphezulu uma kuqhathaniswa nezinga lokushisa legumbi.

Ukuvumelana kungabuye kulungiswe ngokukhetha usayizi wezinhlayiyana nokukhetha ama-cellulose ether anamazinga ahlukene okuguqulwa. Lokhu okubizwa ngokuthi ukuguqulwa ukwethula izinga elithile lokushintshwa kwamaqembu e-hydroxyalkyl esakhiweni samathambo e-MC. Ngokushintsha amanani ashintshile ahlobene ezinto ezimbili ezibambele, okungukuthi, i-DS kanye ne-ms amanani okushintsha ahlobene weqembu le-methoxy ne-hydroxyalkyl esivame ukukusho. Izidingo zokusebenza ezihlukahlukene ze-cellulose ether zingatholwa ngokushintsha amanani ashintshile ahlobene walezi zingxenye ezimbili.

Ubudlelwano phakathi kokuvumelana nokuguqulwa: ukungezwa kwe-cellulose ether kuthinta ukusetshenziswa kwamanzi kodaka, ukushintsha isilinganiso samanzi-isibopho samanzi kanye nosimende kuwumphumela wokuqina, ukuphakama komthamo, kukhulu ukusetshenziswa kwamanzi.

Ama-cellulose ethers asetshenziswa ezintweni zokwakha eziyimpuphu kufanele ahlakazeke ngokushesha emanzini abandayo futhi anikeze ukuhambisana okufanele kwesistimu. Uma inikezwa izinga elithile lokugunda, isala iphenduka i-flocculent futhi i-colloidal block, okuwumkhiqizo osezingeni eliphansi noma ompofu.

Kuphinde kube nobudlelwano obuhle bomugqa phakathi kokuvumelana kokunamathisela usimende kanye nomthamo we-cellulose ether. I-cellulose ether ingakhuphula kakhulu i-viscosity yodaka. Uma umthamo umkhulu, umphumela uba sobala kakhulu. Isixazululo se-aqueous cellulose cellulose ether esine-high-viscosity sine-thixotropy ephezulu, ephinde ibe yisici esikhulu se-cellulose ether. Izixazululo ezinamanzi zama-polymers e-MC zivame ukuba ne-pseudoplastic kanye ne-non-thixotropic fluidity ngaphansi kwezinga lokushisa lejeli, kodwa izakhiwo zokugeleza kwe-Newtonian ngamanani aphansi e-shear. I-Pseudoplasticity iyanda ngesisindo se-molecular noma ukugxila kwe-cellulose ether, kungakhathaliseki ukuthi hlobo luni lwe-substitute kanye nezinga lokushintsha. Ngakho-ke, ama-cellulose ethers webanga elifanayo le-viscosity, kungakhathaliseki ukuthi i-MC, i-HPMC, i-HEMC, izohlale ibonisa izici ezifanayo ze-rheological inqobo nje uma ukugxila nokushisa kugcinwa njalo.

Ama-gel esakhiwo akhiwa lapho izinga lokushisa liphakanyiswa, futhi ukugeleza kwe-thixotropic kakhulu kwenzeka. I-concentration ephezulu kanye ne-viscosity ephansi ye-cellulose ethers ibonisa i-thixotropy ngisho nangaphansi kwezinga lokushisa le-gel. Lesi sakhiwo sinenzuzo enkulu ekulungisweni kokulinganisa nokuwohloka ekwakhiweni kodaka lokwakha. Kudingeka kuchazwe lapha ukuthi ukuphakama kwe-viscosity ye-cellulose ether, ukugcinwa kwamanzi kangcono, kodwa ukuphakama kwe-viscosity, ukuphakama kwesisindo samangqamuzana e-cellulose ether, kanye nokuncipha okuhambisanayo kokuncibilika kwayo, okunomthelela omubi. ekugxilweni kodaka nokusebenza kokwakhiwa. Ukuphakama kwe-viscosity, kusobala kakhulu umphumela wokuqina odongeni, kodwa awulingani ngokuphelele. I-viscosity ethile emaphakathi nephansi, kodwa i-cellulose ether eshintshiwe inokusebenza okungcono ekuthuthukiseni amandla esakhiwo sodaka olumanzi. Ngokukhula kwe-viscosity, ukugcinwa kwamanzi kwe-cellulose ether kuyathuthuka.


Isikhathi sokuthumela: Feb-16-2023
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