Focus on Cellulose ethers

I-HPMC ye-Film Coating

I-HPMC ye-Film Coating

I-HPMC yeUkugqoka ifilimu kuyindlela yokwenza ifilimu elincanyana le-polymer phezu kokulungiswa okuqinile. Isibonelo, ungqimba lwezinto ezizinzile ze-polymer lufuthwe ngokulinganayo phezu kweshidi elingenalutho ngokufafaza indlela yokwenza ungqimba lwefilimu yepulasitiki ama-microns ambalwa agqinsile, ukuze kuzuzwe umphumela oyifunayo. Ukwakheka kwalolu ngqimba lwefilimu ngaphandle kwethebhulethi ukuthi ithebhulethi eyodwa inamathela ezintweni zokumboza i-polymer ngemva kokudlula endaweni yokufutha, bese ithola ingxenye elandelayo yezinto zokumboza ngemva kokumiswa. Ngemuva kokunamathela ngokuphindaphindiwe nokomisa, ukugqoka kuqediwe kuze kube yilapho yonke indawo yokulungiswa ihlanganiswe ngokuphelele. Ukufakwa kwefilimu kuyifilimu eqhubekayo, ukujiya ikakhulukazi phakathi kwama-microns ayi-8 kuye kwayi-100, izinga elithile lokunwebeka nokuguquguquka, kunamathela ngokuqinile ebusweni bomongo.

Ngo-1954, u-Abbott wakhiqiza iqoqo lokuqala lamashidi efilimu atholakalayo kwezohwebo, kusukela ngaleso sikhathi, ngokuthuthuka okuqhubekayo kanye nokuphelela kwemishini yokukhiqiza nobuchwepheshe, kukhishwe izinto zefilimu ze-polymer, ukuze ubuchwepheshe bokugqoka ifilimu buthuthukiswe ngokushesha. Akukhona nje kuphela ukuhlukahluka, ubuningi kanye nekhwalithi yama-ejenti okugqoka imibala kuye kwanda ngokushesha, kodwa futhi izinhlobo, amafomu kanye nezici zobuchwepheshe bokumboza, imishini yokumboza kanye nefilimu yokugqoka kanye nokugqoka amaphilisi e-TCM kuye kwathuthukiswa kakhulu. Ngakho-ke, ukusetshenziswa kobuchwepheshe bokugqoka ifilimu sekuyisidingo nomkhuba wokuthuthukiswa kwamabhizinisi emithi ukuthuthukisa ikhwalithi yomkhiqizo.

Ukusetshenziswa kwangaphambi kwesikhathi ezintweni zokwakha ifilimu yokuhlanganisa ifilimu, kusenenani elikhulu lemikhiqizo esebenzisa i-HPMCi-hydroxypropyl methylcellulosenjengezinto zeMembrane. KuyinhlanzekoI-HPMCi-cellulose evela ku-lint kakotini noma i-pulp yokhuni, nesisombululo se-sodium hydroxide ukukhombisa ukuvuvukala kwe-alkali cellulose, bese ngokwelashwa kwe-chloromethane ne-propylene oxide ukuze uthole i-methyl hydroxypropyl cellulose ether.I-HPMC, umkhiqizo ukususa ukungcola ngemva kokumisa, ukuchotshozwa, ukupakisha. Ngokuvamile, i-viscosity ephansi ye-HPMC isetshenziswa njengeifilimuizinto zokumboza, kanye nesixazululo esingu-2% ~ 10% sisetshenziswa njengesixazululo sokumboza. Okubi ukuthi i-viscosity inkulu kakhulu futhi ukunwetshwa kunamandla kakhulu.

Isizukulwane sesibili sezinto zokwakha ifilimu yi-polyvinyl alcohol (PVA). I-Polyvinyl alcohol yenziwa yi-alcoalysis ye-polyvinyl acetate. Amayunithi aphindayo we-vinyl alcohol awakwazi ukusetshenziswa njengama-reactants ngoba awahlangabezani nenani nobumsulwa obudingekayo ekwenzeni i-polymerization. Ku-methanol, i-ethanol noma i-ethanol ne-methyl acetate isisombululo esixutshwe nensimbi ye-alkali noma i-asidi ye-inorganic njenge-catalyst, i-hydrolysis iyashesha.

I-PVA isetshenziswa kabanzi ekuhlanganiseni ifilimu. Ngenxa yokuthi ayincibiliki emanzini ekamelweni lokushisa, ngokuvamile imbozwe cishe ngo-20% wokuhlakazwa kwamanzi. Umhwamuko wamanzi kanye ne-oxygen permeability ye-PVA iphansi kune-HPMC ne-EC, ngakho ikhono lokuvimba lomhwamuko wamanzi nomoya-mpilo linamandla, elingavikela kangcono i-chip core.

I-Plasticizer ibhekisela entweni engakhuphula ipulasitiki yezinto zokwakha ifilimu. Ezinye izinto zokwakha ifilimu zishintsha izakhiwo zazo ezingokomzimba ngemva kokuba izinga lokushisa lincishisiwe, futhi ukuhamba kwama-macromolecules awo kuba kuncane, okwenza ukunamathela kuqine futhi kube brittle, kuntula ukuguquguquka okudingekayo, futhi ngaleyo ndlela kube lula ukuphuka. I-Plasticizer yengezwe ukunciphisa izinga lokushisa lokushintsha kwengilazi (Tg) nokwandisa ukuguquguquka kokunamathela. Ama-plasticizer asetshenziswa kakhulu ama-amorphous polymers anesisindo samangqamuzana amakhulu futhi asondelene kakhulu nezinto zokwakha ifilimu. I-plasticizer engancibiliki isiza ekunciphiseni ukungena kwe-coating, ngaleyo ndlela ikhulise ukuzinza kokulungiselela.

 

Ngokuvamile kunenkolelo yokuthi indlela ye-plasticizer iwukuthi ama-molecule e-plasticizer ashumekwe ochungechungeni lwe-polymer, oluvimbela ukuxhumana phakathi kwama-molecule e-polymer ngezinga elikhulu. Ukusebenzisana kulula uma ukusebenzisana kwe-polymer-plasticizer kunamandla kunokusebenzelana kwe-polymer-plasticizer. Ngakho-ke, amathuba okuthi izingxenye ze-polymer zihambe ayanda.

Isizukulwane sesithathu sezinto zokwakha ifilimu yi-plasticizer ngendlela yamakhemikhali exhunyelelwe ku-polymer eyenza ifilimu

Isibonelo, into entsha yokwakha ifilimu i-Kollicoat® IR eyethulwe yi-BASF ukuthi i-PEG ixhunywe ngamakhemikhali ochungechungeni olude lwe-PVA polymer ngaphandle kokwengeza i-plasticizer, ukuze igweme ukufuduka kwechibi ngemva kokumbozwa.


Isikhathi sokuthumela: Dec-23-2023
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