Yenziwa njani ihydroxypropylcellulose?

I-Hydroxypropylcellulose (HEC) iphuma kwi-cellulose, i-polymer yendalo efumaneka kwiindonga zeeseli zezityalo. I-HPC isetyenziswa kakhulu kumashishini ahlukeneyo afana namayeza, izinto zokuthambisa kunye nemizi-mveliso yokutya ngenxa yeempawu zayo ezibalaseleyo zokwenza ifilimu kunye nokutyeba. I-synthesis ye-hydroxypropylcellulose ibandakanya amanyathelo amaninzi kwaye inkqubo ingaba nzima.

Intshayelelo yehydroxypropylcellulose:

1. Ukusebenzisa i-cellulose njengesixhobo sokuqala:

Imithombo ephambili ye-cellulose zizinto zezityalo ezifana ne-pulp yomthi okanye ikotoni. I-Cellulose yi-polymer ehambelanayo eyenziwe ngeeyunithi ze-glucose ezidityaniswe ngamabhondi e-β-1,4-glycosidic. Inenqanaba eliphezulu lepolymerization, kunye namawaka eeyunithi zeglucose ezenza amatyathanga amade.

2. Impendulo ye-Etherification:

Ukwenziwa kwe-hydroxypropylcellulose kubandakanya ukuqaliswa kwamaqela e-hydroxypropyl kwi-cellulose backbone nge-etherification. Le mpendulo ibandakanya ukusetyenziswa kwepropylene oxide njenge-alkylating agent.

Iselulosi + ipropylene oxide → ialkali-catalyzed hydroxypropyl cellulose + by-product cellulose + propylene oxide alkali-catalyzed hydroxypropyl cellulose + by-product

Isiseko se-catalysis sibalulekile ukukhuthaza ukusabela phakathi kwamaqela e-cellulose hydroxyl kunye nepropylene oxide. Eli nyathelo lidla ngokuqhutywa phantsi kweemeko ezilawulwayo ukuze kuqinisekiswe iqondo elinqwenelekayo lokutshintshwa (DS) kwamaqela e-hydroxypropyl kwikhonkco leselulosi.

3. IHydroxypropylation:

I-Hydroxypropylation ibandakanya ukongezwa kwamaqela e-hydroxypropyl kwi-cellulose backbone. Olu hlengahlengiso lunika ukunyibilika okuphuculweyo kunye nezinye iipropathi ezinqwenelekayo kwipolymer cellulosic. Iimeko zokusabela, kubandakanywa ubushushu, uxinzelelo kunye nexesha lokuphendula, zilawulwa ngononophelo ukufezekisa iimpawu zemveliso ezifunwayo.

4. Unyango lwealkali:

Emva kwe-hydroxypropylation, unyango lwe-alkaline luhlala lusetyenziselwa ukunciphisa nayiphi na i-acidic eseleyo engcolileyo kunye nokulungelelanisa i-pH yomxube wokuphendula. Eli nyathelo libalulekile kwinkqubo elandelayo yokucoca.

5. Amanyathelo okucoca:

Emva kokusabela kwe-etherification, amanyathelo amaninzi okucoca aqhele ukwenziwa ukufumana i-high-purity hydroxypropylcellulose. La manyathelo angaquka:

Hlamba: Hlamba umxube wokuphendula ukuze ususe ii-reagents ezishiyekileyo, iimveliso eziphumayo kunye neselulosi engaphendulwanga.

Ukuhluzwa: Ukucoca kusetyenziselwa ukwahlula ubumdaka obuqinileyo kumxube wokusabela.

Ukomisa: Iselulosi emanzi yehydroxypropyl iye yomiswa ukuze kususwe nakuphi na ukufuma okushiyekileyo.

6. Ukulawulwa kobunzima bemolekyuli:

Ubunzima be-molecular of hydroxypropylcellulose bunokulawulwa ngexesha lokudibanisa ukulungelelanisa iimpawu zayo kwizicelo ezithile. Oku kuphunyezwa ngokulungelelanisa iimeko zokusabela, njengobungakanani be-reagents kunye nexesha lokuphendula.

Imveliso yemizi-mveliso:

1. Inkqubo engapheliyo okanye eqhubekayo:

Ukuveliswa kwe-hydroxypropyl cellulose kunokwenziwa kwibhetshi okanye iinkqubo eziqhubekayo. Inkqubo yebhetshi ifanelekile kwimveliso encinci, ngelixa inkqubo eqhubekayo ifaneleka ngakumbi kwimveliso enkulu.

2. Ulawulo lomgangatho:

Amanyathelo okulawula umgangatho aphunyezwa kuzo zonke izigaba zenkqubo yokuvelisa ukuqinisekisa ukuhambelana kunye nokucoceka kwemveliso yokugqibela. Iindlela zokuhlalutya ezifana nechromatography, i-spectroscopy kunye nezifundo ze-rheological zisetyenziselwa ukuvavanya iiparamitha eziphambili ezifana neqondo lokuthatha indawo, ubunzima bemolekyuli kunye nokucoceka.

Ukusetyenziswa kweSelulosi yeHydroxypropyl:

1. Ishishini lamachiza:

I-Hydroxypropylcellulose isetyenziswa ngokubanzi kumalungiselelo amayeza njenge-binder, i-disintegrant kunye ne-ejenti yokukhululwa elawulwayo. Ukuhambelana kwayo kunye noluhlu olubanzi lwamachiza kunye nokungazenzi kwayo kuyenza ibe ngumxhasi oguquguqukayo.

2. Ishishini lezithambiso:

Kwishishini lezithambiso, i-hydroxypropylcellulose isetyenziswa ekuqulunqweni kweemveliso zokhathalelo lweenwele, iikhrimu zesikhumba kunye nezinye iimveliso zokhathalelo lomntu. Iimpawu zayo zokwenza ifilimu zenza ukuba zixabiseke kwiimveliso zokunakekelwa kweenwele.

3. Ishishini lokutya:

Kwishishini lokutya, i-hydroxypropylcellulose isetyenziswa njenge-thickener kunye ne-gelling agent. Ifumaneka kwiindidi zokutya kwaye inceda ukuphucula ukuthungwa nokuzinza kwabo.

I-synthesis ye-hydroxypropylcellulose ibandakanya i-etherification ye-cellulose ngokongezwa kwamaqela e-hydroxypropyl. Ukusabela ngokuqhelekileyo kubangelwa yisiseko, kulandelwa ngamanyathelo okucoca ukufumana imveliso ecocekileyo kakhulu. Ukuveliswa kwemizi-mveliso kunokwenziwa ngebhetshi okanye iinkqubo eziqhubekayo kunye namanyathelo okulawula umgangatho ongqongqo. IHydroxypropylcellulose inoluhlu olubanzi lwezicelo kumashishini amayeza, izimonyo kunye nokutya ngenxa yeempawu zayo ezizodwa kunye nokuguquguquka. Ukuphuculwa okuqhubekayo kweenkqubo zemveliso kunye nophuhliso lwezicelo ezintsha kugxininisa