Focus on Cellulose ethers

Izinto ezithinta indawo yokuncibilika kwe-hydroxyethyl cellulose

I-Hydroxyethyl cellulose (HEC) iyi-ether ye-cellulose encibilikayo ebalulekile emanzini, esetshenziswa kakhulu embotsheni, ekubhobozeni uwoyela, ekwekhemisi nakwezinye izindawo. Iphuzu layo lokuncibilika liyipharamitha ebalulekile yomzimba ethinta ukucubungula nokusetshenziswa kwayo. Izinto ezithinta indawo encibilikayo ye-hydroxyethyl cellulose zingahlukaniswa zibe izici ezimbalwa, njengesakhiwo samangqamuzana, izinga lokushintshwa, isisindo samangqamuzana, icrystallinity, ukungcola, nezimo zemvelo.

1. Isakhiwo samangqamuzana

I-Hydroxyethyl cellulose ingumkhiqizo we-cellulose ngemuva kwe-ethoxylation. Isakhiwo sawo esiyisisekelo ukuthi ama-athomu e-hydrogen ku-molecule ye-cellulose athathelwa indawo amaqembu e-hydroxyethyl. Indawo, inombolo kanye nokuhleleka kokushintshwa kwe-hydroxyethyl kuzothinta indawo yayo yokuncibilika.
Indawo yokushintshanisa: Iyunithi ngayinye ye-glucose ku-cellulose inamaqembu amathathu e-hydroxyl angashintshwa. Ukushintshwa ezindaweni ezihlukene kuzoshintsha ukwakheka kwendawo ye-molecule, ngaleyo ndlela kuthinte indawo yokuncibilika.
Inani lokushintshwa: Ukwanda kwenani lezinto ezihlukile ngokuvamile kunciphisa ukuhlangana kwe-hydrogen phakathi kwama-molecule, ngaleyo ndlela kunciphisa indawo yokuncibilika.
Ukuhleleka kokuhlelwa okushintshile: Okushintshwayo okusatshalaliswa ngokungahleliwe kanye nezinye ezisatshalaliswa njalo zinemithelela ehlukile evumelana nezimo nokusebenzelana kweketango lamangqamuzana, ngaleyo ndlela kuthinte indawo yokuncibilika.

2. Iziqu Zokushintsha (DS)

I-DS ibhekisela enanini elimaphakathi lama-hydroxyethyl eyunithi ngayinye ye-glucose. Izinga lokushintsha linomthelela obalulekile endaweni yokuncibilika, okubonakala kakhulu kulezi zici ezilandelayo:
I-DS ephansi: Nge-DS ephansi, ukuhlangana kwe-hydrogen phakathi kwama-molecule e-hydroxyethyl cellulose kunamandla, okwenza ama-molecule aboshwe ngokuqinile futhi indawo yokuncibilika ibe phezulu.

I-DS Ephakeme: I-DS ephezulu inyusa ukuguquguquka kwama-molecule futhi inciphisa umthelela we-hydrogen bonding, okwenza ama-molecule asheleleke kalula futhi iphoyinti elincibilikayo libe phansi.

3. Isisindo samangqamuzana

Isisindo samangqamuzana sinomthelela oqondile endaweni encibilikayo ye-hydroxyethyl cellulose. Ngokuvamile, lapho isisindo samangqamuzana sikhulu, iketango lamangqamuzana liba lide, amandla e-van der Waals anamandla phakathi kwama-molecule, futhi kuyanda indawo yokuncibilika. Ngaphezu kwalokho, ububanzi bokusabalalisa isisindo samangqamuzana kuzophinde kuthinte indawo yokuncibilika, futhi ukusatshalaliswa okubanzi kungase kuholele kumaphuzu okuncibilika angalingani.

Isisindo samangqamuzana aphezulu: Amaketanga amangqamuzana amade, abambene kakhulu, futhi indawo yokuncibilika iphezulu.

Isisindo samangqamuzana aphansi: Amaketanga e-molecular mafushane, amandla e-intermolecular abuthakathaka, futhi iphuzu lokuncibilika liphansi.

4. I-Crystallinity

I-Hydroxyethyl cellulose iyi-polymer e-amorphous, kodwa ingase ibe nezindawo ezithile zekristalu. Ukuba khona kwezifunda ze-crystalline kwandisa iphuzu lokuncibilika ngenxa yokuthi isakhiwo se-crystalline sizinzile futhi sidinga amandla engeziwe ukuze aphule lezi zakhiwo ezihlelekile. Izinga le-hydroxyethylation nezimo zenqubo zithinta ubucwebe bayo.
I-crystallinity ephezulu: isakhiwo esiqinile, indawo ephakeme yokuncibilika.
I-crystallinity ephansi: isakhiwo esixegayo, indawo encibilikayo ephansi.

5. Ukungcola

Ngesikhathi sokukhiqizwa kwe-hydroxyethyl cellulose, ezinye izinto zokusetshenziswa ezingaphenduliwe, ama-catalysts noma imikhiqizo ephumayo zingahlala. Ukuba khona kwalokhu kungcola kungase kuguqule amandla e-intermolecular, ngaleyo ndlela kuthinte iphuzu lokuncibilika. Ngokwesibonelo:
I-catalyst eyinsalela: ama-complexes angase akheke, ashintshe indawo yokuncibilika.
Imikhiqizo: Ukuba khona kwemikhiqizo ehlukile kuzoshintsha ukusebenzisana kwesistimu futhi kuthinte indawo yokuncibilika.

6. Izimo zemvelo

Izimo zemvelo ezifana nezinga lokushisa nomswakama zizophazamisa indawo yokuncibilika kwe-hydroxyethyl cellulose. Ngaphansi kwezimo zokuswakama okuphezulu, i-hydroxyethyl cellulose izokwenziwa ipulasitiki ngemuva kokumunca amanzi, okuzokwenza buthaka amandla e-intermolecular futhi kunciphise indawo yokuncibilika.
Izinga lokushisa eliphezulu: Kungase kubangele ukubola okushisayo kwempahla futhi kunwebe indawo encibilikayo.
Umswakama ophezulu: Iketango lamangqamuzana likwazi ukuguquguquka kakhulu ngemva kokumunca amanzi, futhi iphuzu lokuncibilika liyancipha.

7. Ukucubungula Ubuchwepheshe

Izinga lokushisa, amandla okugunda, izimo zokomisa, njll. phakathi nenqubo yokucubungula kuzothinta indawo yokuncibilika yomkhiqizo wokugcina. Izimo ezihlukene zokucubungula zizoholela emazingeni ahlukene we-molecular and crystallinity, okubuye kuthinte iphuzu lokuncibilika.
Izinga lokushisa lokucubungula: Amazinga okushisa aphezulu okucubungula angase abangele ukuwohloka okuncane noma ukuxhumanisa, ukushintsha indawo yokuncibilika.
Izimo zokomisa: Ukomisa ngokushesha nokomisa kancane kunemiphumela ehlukene ekuhlelweni kwama-molecule, futhi indawo yokuncibilika nayo izohluka.

Kafushane, izici ezithinta indawo yokuncibilika kwe-hydroxyethyl cellulose zihlanganisa isakhiwo samangqamuzana, izinga lokushintshwa, isisindo samangqamuzana, i-crystallinity, ukungcola, izimo zemvelo kanye nokucubungula ubuchwepheshe. Ngokusetshenziswa okungokoqobo nokucutshungulwa, ukulawula okunengqondo kwalezi zici kungathuthukisa ukusebenza kwe-hydroxyethyl cellulose futhi kuyenze ihlangabezane kangcono nezimfuneko zohlelo lokusebenza. Enqubweni yokukhiqiza, ukulungiswa kwesayensi yale mingcele akukwazi nje ukulawula indawo yokuncibilika komkhiqizo, kodwa futhi kuthuthukise ukuzinza kanye nekhwalithi yomkhiqizo.


Isikhathi sokuthumela: Jul-10-2024
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