Focus on Cellulose ethers

Sidee loo soo saaraa Hydroxypropyl Methylcellulose (HPMC)?

Hydroxypropyl methylcellulose (HPMC) waa polymer-ka-milmi--synthetic-ka ah ee biyaha ku milma oo caadi ahaan loo isticmaalo dawooyinka, dhismaha iyo warshadaha cuntada, iyo kuwa kale. Waxaa laga soo qaatay cellulose, polymer dabiici ah oo laga helo gidaarada unugyada dhirta. Kuwa soo socda waa dulmar guud oo ku saabsan habka wax soo saarka HPMC:

Isha cellulose:

Qalabka ugu muhiimsan ee wax soo saarka HPMC waa cellulose, kaas oo laga heli karo saxarka alwaax ama suufka. Saxarka alwaaxdu waa il caadi ah sababtoo ah waa mid aad u badan oo kharash-ool ah.

Daaweynta Alkali:

Cellulose waxaa lagu daaweeyaa alkali (badanaa sodium hydroxide) si looga saaro wasakhda iyo hemicellulose. Nidaamkan, oo loo yaqaan 'mercerization', wuxuu soo saaraa cellulose sifaysan.

Etherification:

Cellulose-ka la safeeyey ayaa markaa la hoosgeliyaa etherification, fal-celin kiimikaad oo soo bandhigta kooxaha etherka ee laf-dhabarka cellulose. HPMC, labada kooxood ee hydroxypropyl iyo methyl waxaa lagu soo bandhigaa molecule cellulose.

Hydroxypropylation:

Propylene oxide waxaa loo isticmaalaa in lagu soo bandhigo kooxaha hydroxypropyl cellulose. Talaabadani waxay ku lug leedahay falcelinta propylene oxide iyo cellulose iyadoo ay jirto kiciye.

Methylation:

Kooxaha Methyl waxaa lagu soo bandhigaa hydroxypropylated cellulose iyadoo la isticmaalayo methyl chloride ama dimethyl sulfate. Tallaabadan waxaa loo yaqaan methylation.

Dhexdhexaadinta iyo dhaqidda:

Ka dib falcelinta etherification, alaabtu waa dhexdhexaad si meesha looga saaro saldhig kasta oo hadhay. HPMC-ga soo baxay ayaa markaa la dhaqaa si looga saaro alaabada iyo kiimikooyinka aan falcelinta lahayn.

qalajin:

Tallaabada ugu dambeysa waxay ku lug leedahay qalajinta HPMC si meesha looga saaro biyaha xad dhaafka ah oo loo helo badeecada la rabo oo ah budo ama qaab granular ah.

Waxaa muhiim ah in la ogaado in faahfaahinta gaarka ah ee habka wax soo saarka ay ku kala duwanaan karaan soo saarayaasha, waxaana laga yaabaa inay isticmaalaan shuruudo kala duwan, kiciyayaal, iyo reagents si loo gaaro waxqabadka la rabo ee HPMC. Intaa waxaa dheer, tallaabooyinka xakamaynta tayada ayaa lafuliyaa inta lagu guda jiro habka wax soo saarka si loo hubiyo joogtaynta iyo nadiifnimada alaabta ugu dambeysa.


Waqtiga boostada: Nov-24-2023
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