Focus on Cellulose ethers

Liphello tsa Li-substituents le Boima ba Limolek'hule ho Thepa e Ntle ea Nonionic Cellulose Ether

Liphello tsa Li-substituents le Boima ba Limolek'hule ho Thepa e Ntle ea Nonionic Cellulose Ether

Ho ea ka khopolo ea ho kenngoa ha Washburn (Khopolo ea ho kenella) le khopolo ea motsoako oa van Oss-Good-Chaudhury (Khopolo-kopano) le ts'ebeliso ea theknoloji ea mohala oa mohala (Column Wicking Technique), li-ether tse 'maloa tse seng tsa ionic cellulose, tse kang methyl cellulose cellulose, hydroxypropyl cellulose le hydroxypropyl methylcellulose li ile tsa lekoa. Ka lebaka la li-substitute tse fapaneng, li-degree tsa substitution le boima ba limolek'hule tsa li-cellulose ethers, matla a tsona a holim'a metsi le likarolo tsa tsona li fapane haholo. Lintlha li bontša hore setsi sa Lewis sa non-ionic cellulose ether se seholo ho feta Lewis acid, 'me karolo e ka sehloohong ea matla a mahala a holim'a metsi ke matla a Lifshitz-van der Waals. Matla a kaholimo a hydroxypropyl le sebopeho sa eona a maholo ho feta a hydroxymethyl. Tlas'a motheo oa sebaka se tšoanang le tekanyo ea ho fetola, matla a mahala a hydroxypropyl cellulose a lekana le boima ba molek'hule; ha matla a mahala a hydroxypropyl methylcellulose a lekana le tekanyo ea ho nkela sebaka 'me a lekana ka tsela e fapaneng le boima ba molek'hule. Teko e boetse e fumane hore matla a kaholimo a hydroxypropyl le hydroxypropylmethyl ka har'a non-ionic cellulose ether a bonahala a le matla ho feta matla a selulose, 'me teko e paka hore matla a holim'a cellulose e lekiloeng le sebopeho sa eona. e tsamaellanang le lingoliloeng.

Mantsoe a bohlokoa: nonionic cellulose ethers; baemedi le dikgato tsa phapanyetso; boima ba molek'hule; thepa ea bokaholimo; theknoloji ea wick

 

Cellulose ether ke sehlopha se seholo sa lihlahisoa tsa cellulose, tse ka aroloa ka li-ether tsa anionic, cationic le nonionic ho ea ka sebopeho sa lik'hemik'hale tsa li-substituent tsa tsona tsa ether. Cellulose ether le eona ke e 'ngoe ea lihlahisoa tsa pele tse entsoeng lipatlisiso le ho hlahisoa k'hemistri ea polymer. Ho fihlela joale, cellulose ether e se e sebelisoa haholo meriana, bohloeki, litlolo le indasteri ea lijo.

Le hoja li-cellulose ethers, tse kang hydroxymethylcellulose, hydroxypropylcellulose le hydroxypropylmethylcellulose, li 'nile tsa hlahisoa indastering' me boholo ba thepa ea bona e 'nile ea ithutoa, matla a bona a holim'a metsi, thepa ea acid Alkali-reactive ha e e-s'o tlalehoe ho fihlela joale. Kaha boholo ba lihlahisoa tsena li sebelisoa sebakeng sa mokelikeli, 'me litšobotsi tse ka holim'a metsi, haholo-holo litšoaneleho tsa karabelo ea acid-base, li ka ama ts'ebeliso ea tsona, ho bohlokoa haholo ho ithuta le ho utloisisa litšobotsi tsa lik'hemik'hale tse ka holimo tsa selulose ether ea khoebo.

Ha ho nahanoa hore mehlala ea lihlahisoa tsa cellulose e bonolo haholo ho e fetola ka phetoho ea maemo a ho itokisa, pampiri ena e sebelisa lihlahisoa tsa khoebo e le mehlala ho bontša matla a bona a holim'a metsi, 'me ho itšetlehile ka sena, tšusumetso ea li-substituents le boima ba limolek'hule tsa lihlahisoa tse joalo holim'a metsi. thepa ea ithutoa.

 

1. Karolo ea teko

1.1 Lisebelisoa tse tala

The non-ionic cellulose ether e sebelisitsoeng tekong ke sehlahisoa saKIMA CHEMICAL CO.,LTD,. Mehlala ha ea ka ea fuoa phekolo leha e le efe pele ho hlahlojoa.

Ha ho nahanoa hore lihlahisoa tsa selulose li entsoe ka selulose, mehaho e 'meli e haufi,' me thepa ea holim'a selulose e tlalehiloe libukeng, kahoo pampiri ena e sebelisa selulose e le mohlala o tloaelehileng. Mohlala oa selulose o sebelisitsoeng o ne o rehiloe lebitso la khoutu C8002 mme o ile oa rekoa hoKIMA, CN. Sampole ha ea ka ea fuoa phekolo leha e le efe nakong ea tlhahlobo.

Li-reagents tse sebelisitsoeng tekong ke: ethane, diiodomethane, deionized water, formamide, toluene, chloroform. Mekelikeli eohle e ne e le lihlahisoa tse hloekileng ntle le metsi a neng a fumaneha khoebong.

1.2 Mokhoa oa liteko

Tekong ena, mokhoa oa ho roala litšiea o ile oa amoheloa, 'me karolo (e ka bang 10 cm) ea pipette e tloaelehileng e nang le bophara bo ka hare ba 3 mm e ile ea khaoloa e le tube ea kholomo. Kenya 200 mg ea sampole ea phofshoana ka har'a tube ea kholomo nako le nako, ebe u e tsokotsa ho etsa hore e be bonolo 'me u e behe ka tlase ho sets'oants'o sa khalase ka bophara bo ka bang 3 cm, e le hore mokelikeli o ka ikemela. Beha boima ba 1 mL ea mokelikeli o lokelang ho lekoa ebe o o kenya ka har'a sets'oants'o sa khalase, 'me u tlalehe nako ea ho qoelisoa t le sebaka sa ho qoelisoa X ka nako e le 'ngoe. Liteko tsohle li entsoe ka mocheso oa kamore (25±1°C). Lintlha ka 'ngoe ke kakaretso ea liteko tse tharo tse ikatisang.

1.3 Palo ea lintlha tsa liteko

Motheo oa khopolo-taba oa ts'ebeliso ea mokhoa oa ho hlakola likholomo ho leka matla a holim'a lisebelisoa tsa phofo ke Washburn impregnation equation (Washburn penetration equation).

1.3.1 Qeto ea radius e sebetsang ea capillary Reff ea sampole e lekantsoeng

Ha u sebelisa mokhoa oa ho qoelisoa oa Washburn, boemo ba ho fumana ho koloba ka ho feletseng ke cos=1. Sena se bolela hore ha mokelikeli o khethoa hore o qoelisoe ho tiileng ho fihlela boemo bo metsi ka ho feletseng, re ka bala radius e sebetsang ea capillary Reff ea sampole e lekantsoeng ka ho hlahloba sebaka sa ho qoelisoa le nako ho ea ka nyeoe e khethehileng ea mokhoa oa ho qoelisoa oa Washburn.

1.3.2 Lifshitz-van der Waals Palo ea matla bakeng sa sampole e lekantsoeng

Ho latela melao e kopantseng ea van Oss-Chaudhury-Good, kamano lipakeng tsa karabelo lipakeng tsa maro le lintho tse tiileng.

1.3.3 Palo ea Lewis acid-base force ea disampole tse lekantsoeng

Ka kakaretso, thepa ea acid-base ea solids e hakanngoa ho tsoa ho data e kentsoeng ka metsi le formamide. Empa sehloohong sena, re fumane hore ha ho na bothata ha ho sebelisoa maro a polar ho lekanya selulose, empa tekong ea cellulose ether, hobane bophahamo ba ho qoelisoa ha tsamaiso ea polar ea metsi / formamide ka cellulose ether e tlaase haholo. , ho etsa hore nako ea ho rekota e be thata haholo. Ka hona, tsamaiso ea tharollo ea toluene/chloroform e hlahisitsoeng ke Chibowsk e ile ea khethoa. Ho ea ka Chibowski, tsamaiso ea tharollo ea polar ea toluene / chloroform le eona ke khetho. Sena ke hobane lino tse peli li na le asiti e khethehileng haholo le alkalinity, mohlala, toluene ha e na Lewis acidity, 'me chloroform ha e na Lewis alkalinity. E le ho fumana lintlha tse fumanoeng ke tsamaiso ea toluene/chloroform e haufi le tsamaiso e khothalletsoang ea polar solution ea metsi/formamide, re sebelisa litsamaiso tsena tse peli tsa metsi a polar ho lekola cellulose ka nako e le 'ngoe, ebe re fumana li-coefficients tse tsamaellanang tsa katoloso kapa konteraka. pele o sebelisa Lintlha tse fumanoeng ka ho kenya cellulose ether ka toluene/chloroform li haufi le liqeto tse fumanoeng bakeng sa tsamaiso ea metsi/formamide. Kaha li-cellulose ethers li tsoa ho selulose 'me ho na le sebopeho se ts'oanang haholo pakeng tsa tse peli, mokhoa ona oa khakanyo o ka sebetsa.

1.3.4 Palo ea matla a mahala a holim'a metsi

 

2. Liphetho le Puisano

2.1 Tekanyetso ea cellulose

Kaha liphetho tsa liteko tsa rona ho lisampole tse tloaelehileng tsa cellulose li fumane hore lintlha tsena li lumellana hantle le tse tlalehiloeng libukeng, hoa utloahala ho lumela hore liphetho tsa liteko tsa li-cellulose ether le tsona li lokela ho nahanoa.

2.2 Liphetho tsa liteko le puisano ea cellulose ether

Nakong ea teko ea cellulose ether, ho thata haholo ho hatisa sebaka sa ho qoelisoa le nako ka lebaka la bophahamo bo tlaase haholo ba ho qoelisoa ha metsi le formamide. Ka hona, pampiri ena e khetha tsamaiso ea tharollo ea toluene / chloroform e le tharollo e 'ngoe,' me e hakanya acidity ea Lewis ea cellulose ether ho latela liphello tsa liteko tsa metsi / formamide le toluene / chloroform ka selulose le kamano e lekanang pakeng tsa mekhoa e 'meli ea tharollo. le matla a alkaline.

Ho nka selulose e le sampuli e tloaelehileng, ho fanoa ka letoto la litšobotsi tsa acid-base tsa cellulose ethers. Kaha phello ea ho kenya cellulose ether ka toluene/chloroform e lekoa ka ho toba, e ea kholisa.

Sena se bolela hore mofuta le boima ba limolek'hule tsa li-substitutes li ama thepa ea acid-base ea cellulose ether, le kamano pakeng tsa likarolo tse peli, hydroxypropyl le hydroxypropylmethyl, ho thepa ea acid-base ea cellulose ether le boima ba molek'hule bo fapaneng ka ho feletseng. Empa e ka boela ea amana le taba ea hore MPs are mixed substituents.

Kaha li-substitute tsa MO43 le K8913 li fapane ebile li na le boima ba limolek'hule tse tšoanang, mohlala, sebaka sa pele ke hydroxymethyl 'me sebaka sa ea morao-rao ke hydroxypropyl, empa boima ba limolek'hule ka bobeli ke 100,000, ka hona ho bolela hore motheo oa boima bo tšoanang ba molek'hule Tlas'a maemo, S + le S- ea sehlopha sa hydroxymethyl e ka ba nyane ho feta sehlopha sa hydroxypropyl. Empa tekanyo ea ho kenya sebaka hape e ka khoneha, hobane tekanyo ea ho fetola K8913 e ka bang 3.00, athe ea MO43 ke 1.90 feela.

Kaha tekanyo ea ho kenya sebaka le likarolo tsa K8913 le K9113 li tšoana empa boima ba limolek'hule feela bo fapane, papiso pakeng tsa tse peli e bontša hore S + ea hydroxypropyl cellulose e fokotseha ka ho eketseha ha boima ba limolek'hule, empa S- e eketseha ho fapana le hoo. .

Ho tsoa kakaretso ea liphetho tsa liteko tsa matla a holim'a li-ethers tsohle tsa cellulose le likarolo tsa tsona, ho ka bonoa hore ebang ke cellulose kapa cellulose ether, karolo e kholo ea matla a bona a holim'a metsi ke matla a Lifshitz-van der Waals, a ikarabellang hoo e ka bang 98% ~ 99%. Ho feta moo, matla a Lifshitz-van der Waals a li-nonionic cellulose ethers (ntle le MO43) le ona a boholo ho feta a cellulose, e leng se bontšang hore mokhoa oa etherification oa cellulose hape ke mokhoa oa ho eketsa matla a Lifshitz-van der Waals. 'Me keketseho ena e lebisa ho matla a holim'a cellulose ether ho feta a cellulose. Ketsahalo ena e thahasellisa haholo hobane li-ethers tsena tsa cellulose li sebelisoa hangata ha ho etsoa li-surfactants. Empa lintlha li bohlokoa haholo, eseng feela hobane lintlha tse mabapi le sampole ea litšupiso tse lekiloeng tekong ena li lumellana haholo le boleng bo tlalehiloeng libukeng, lintlha tse mabapi le sampole e tloaelehileng ea litšupiso li lumellana haholo le boleng bo tlalehiloeng libukeng. mohlala: cellulose tsena kaofela SAB ea ethers e nyane haholo ho feta ea cellulose, 'me sena se bakoa ke metheo ea bona e meholo ea Lewis. Tlas'a motheo oa sebaka se tšoanang le tekanyo ea ho fetola, matla a mahala a hydroxypropyl cellulose a lekana le boima ba molek'hule; ha matla a mahala a hydroxypropyl methylcellulose a lekana le tekanyo ea ho nkela sebaka 'me a lekana ka tsela e fapaneng le boima ba molek'hule.

Ho phaella moo, hobane li-cellulose ethers li na le SLW e kholoanyane ho feta selulose, empa re se re ntse re tseba hore dispersibility ea bona e molemo ho feta selulose, kahoo ho ka nkoa esale pele hore karolo e ka sehloohong ea SLW e etsang li-nonionic cellulose ethers e lokela ho ba matla a London.

 

3. Qetello

Liphuputso li bontšitse hore mofuta oa sebaka, tekanyo ea ho fetola le boima ba limolek'hule li na le tšusumetso e kholo holim'a matla a holim'a metsi le sebopeho sa ether e seng ea ionic cellulose. 'Me phello ena e bonahala e na le maemo a latelang:

(1) S+ ea non-ionic cellulose ether e nyane ho feta S-.

(2) Matla a bokaholimo ba nonionic cellulose ether a laoloa ke matla a Lifshitz-van der Waals.

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(4) Tlas'a motheo oa sebaka se tšoanang le tekanyo ea ho fetola, matla a mahala a hydroxypropyl cellulose a lekana le boima ba molek'hule; ha matla a mahala a hydroxypropyl methylcellulose a lekana le tekanyo ea ho nkela sebaka 'me a lekana ka tsela e fapaneng le boima ba molek'hule.

(5) Ts'ebetso ea etherification ea cellulose ke ts'ebetso eo matla a Lifshitz-van der Waals a eketsehang ka eona, hape ke ts'ebetso eo acidity ea Lewis e fokotsehang le Lewis alkalinity e eketsehang.


Nako ea poso: Mar-13-2023
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