Focus on Cellulose ethers

Sidee loo sameeyaa hydroxypropylcellulose?

Hydroxypropylcellulose (HEC) waa unug ka soo jeeda cellulose, polymer dabiici ah oo laga helo gidaarada unugyada dhirta.HPC waxaa si weyn loogu isticmaalaa warshadaha kala duwan sida daawooyinka, qurxinta iyo warshadaha cuntada ay sabab u tahay aflaanta-samaynta iyo dhumucdiisu aad u fiican.Isku-dubaridka hydroxypropylcellulose waxay ku lug leedahay tillaabooyin badan oo geeddi-socodku wuxuu noqon karaa mid adag.

Hordhac hydroxypropylcellulose:

1. Isticmaalka cellulose sida alaabta bilawga ah:

Ilaha ugu muhiimsan ee cellulose waa alaabta dhirta sida saxarka alwaax ama suufka.Cellulose waa polymer toosan oo ka kooban unugyo gulukoos oo ku xiran β-1,4-glycosidic bonds.Waxay leedahay polymerization heer sare ah, oo kumanaan unug gulukoos ah ay sameeyaan silsilado dhaadheer.

2. Falcelinta Etherification:

Isku dhafka hydroxypropylcellulose wuxuu ku lug leeyahay soo bandhigida kooxaha hydroxypropyl ee laf-dhabarka cellulose iyada oo loo marayo etherification.Dareen-celintani waxay caadi ahaan ku lug leedahay isticmaalka propylene oxide sida wakiilka alkylating.

Cellulose + propylene oxide → alkali-catalyzed hydroxypropyl cellulose + wax soo saarka cellulose + propylene oxide alkali-catalyzed hydroxypropyl cellulose + by-product

Catalysis salka waa lama huraan si kor loogu qaado falcelinta ka dhexeeya kooxaha cellulose hydroxyl iyo propylene oxide.Talaabadan waxaa sida caadiga ah lagu fuliyaa xaalado la kantaroolo si loo hubiyo heerka la rabo ee beddelka (DS) ee kooxaha hydroxypropyl ee silsiladda cellulose.

3. Hydroxypropylation:

Hydroxypropylation waxay ku lug leedahay ku-darka kooxaha hydroxypropyl ee laf-dhabarka cellulose.Wax ka beddelkaani waxa uu sii wanaajiyay milanka iyo guryaha kale ee la jecel yahay ee polymer-ka cellulosic.Xaaladaha falcelinta, oo ay ku jiraan heerkulka, cadaadiska iyo wakhtiga falcelinta, ayaa si taxadar leh loo xakameeyaa si loo gaaro sifooyinka alaabta ee la doonayo.

4. Daaweynta Alkali:

Ka dib hydroxypropylation, daaweynta alkaline waxaa badanaa loo isticmaalaa in laga takhaluso wax kasta oo wasakh ah oo aashitada ah oo la hagaajiyo pH ee isku dhafka falcelinta.Tallaabadani waxay muhiim u tahay habka nadiifinta xiga.

5. Tallaabooyinka nadiifinta:

Dareen-celinta etherification ka dib, dhowr tillaabo oo nadiifin ah ayaa badanaa la sameeyaa si loo helo hydroxypropylcellulose saafi ah oo sarreeya.Talaabooyinkan waxaa ka mid noqon kara:

Dhaq: Maydh isku darka falcelinta si aad uga saarto reagen-yaasha haraaga ah, alaabada ka samaysan iyo cellulose aan falcelin lahayn.

Shaandhaynta: Shaandhaynta waxaa loo isticmaalaa in lagu kala saaro wasakhda adag iyo isku darka falcelinta.

Qalajinta: cellulose hydroxypropyl qoyan ayaa markaa la qalajiyey si looga saaro qoyaanka hadhay.

6. Xakamaynta miisaanka molecular:

Miisaanka molecular ee hydroxypropylcellulose waa la xakameyn karaa inta lagu guda jiro isku-dubarid si loogu habeeyo hantideeda codsiyo gaar ah.Tan waxaa lagu gaaraa iyadoo la hagaajinayo xaaladaha falcelinta, sida qadarka reagents iyo waqtiga falcelinta.

Wax soo saarka warshadaha:

1. Nidaam joogto ah ama joogto ah:

Soo saarista hydroxypropyl cellulose waxaa lagu fuliyaa habraacyo dufcad ah ama joogto ah.Habka dufcaddu wuxuu ku habboon yahay wax-soo-saarka yar-yar, halka habka joogtada ahi uu ku habboon yahay wax-soo-saarka ballaaran.

2. Xakamaynta tayada:

Tallaabooyinka xakamaynta tayada waxaa lagu fuliyaa dhammaan heerarka habka wax soo saarka si loo hubiyo joogtaynta iyo nadiifnimada alaabta ugu dambeysa.Farsamooyinka falanqaynta sida chromatography, spectroscopy iyo rheological Studies ayaa loo isticmaalaa si loo qiimeeyo cabbirrada muhiimka ah sida heerka beddelka, miisaanka unugyada iyo nadiifnimada.

Codsiyada Hydroxypropyl Cellulose:

1. Warshadaha dawooyinka:

Hydroxypropylcellulose waxaa si weyn loogu isticmaalaa diyaargarowga dawooyinka sidii xire, kala daadsan iyo wakiilka sii daynta la kantaroolo.La jaanqaadkeeda daawooyin kala duwan iyo firfircoonideedu waxay ka dhigaysaa wax-soo-saar badan.

2. Warshadaha qurxinta:

Warshadaha qurxinta, hydroxypropylcellulose waxaa loo isticmaalaa samaynta alaabta daryeelka timaha, kiriimyada maqaarka iyo alaabta kale ee daryeelka shakhsi ahaaneed.Alaabta sameynta filimku waxay ka dhigtaa mid qiimo leh alaabta daryeelka timaha.

3. Warshadaha cuntada:

Warshadaha cuntada, hydroxypropylcellulose waxaa loo isticmaalaa sidii dhumuc iyo wakiilka jelling.Waxaa laga helaa cuntooyin kala duwan waxayna ka caawisaa hagaajinta jirkooda iyo xasiloonidooda.

Isku dhafka hydroxypropylcellulose wuxuu ku lug leeyahay etherification ee cellulose iyadoo lagu daro kooxaha hydroxypropyl.Dareen-celinta waxaa sida caadiga ah kataliya saldhig, oo ay ku xigto tillaabooyin sifeyn si loo helo badeeco saafi ah.Wax soo saarka warshadaha waxaa lagu fulin karaa habraacyo dufcad ah ama joogto ah oo leh tallaabooyin adag oo lagu xakameynayo tayada.Hydroxypropylcellulose waxay leedahay codsiyo kala duwan oo kala duwan oo ku jira warshadaha dawooyinka, qurxinta iyo warshadaha cuntada taas oo ay ugu wacan tahay sifooyinkeeda gaarka ah iyo kala duwanaanshiyaha.Horumarinta joogtada ah ee hababka wax soo saarka iyo horumarinta codsiyada cusub waxay xoogga saaraan


Waqtiga boostada: Dec-26-2023
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