Focus on Cellulose ethers

I-Degree of Substitution Determination Method ye-Sodium Carboxymethyl Cellulose

I-Degree of Substitution Determination Method ye-Sodium Carboxymethyl Cellulose

Ukunquma izinga lokushintshwa (i-DS) le-sodium carboxymethyl cellulose (CMC) kubalulekile ekulawuleni ikhwalithi nokuqinisekisa ukuvumelana kwezakhiwo nokusebenza kwayo.Izindlela ezimbalwa zingasetshenziswa ukunquma i-DS ye-CMC, ngamasu e-titration kanye ne-spectroscopic asetshenziswa kakhulu.Nansi incazelo eningiliziwe yendlela ye-titration yokunquma i-DS ye-sodium CMC:

1. Isimiso:

  • Indlela ye-titration incike ekuphenduleni phakathi kwamaqembu e-carboxymethyl ku-CMC kanye nesisombululo esijwayelekile sesisekelo esiqinile, ngokuvamile i-sodium hydroxide (NaOH), ngaphansi kwezimo ezilawulwayo.
  • Amaqembu e-Carboxymethyl (-CH2-COOH) ku-CMC asabela nge-NaOH ukuze akhe i-sodium carboxylate (-CH2-COONA) namanzi.Izinga lalokhu kusabela lilingana nenani lamaqembu e-carboxymethyl akhona ku-molecule ye-CMC.

2. Ama-reagents nezisetshenziswa:

  • Isixazululo esijwayelekile se-sodium hydroxide (NaOH) sokugxila okwaziwayo.
  • Isampula ye-CMC.
  • Inkomba ye-Acid-base (isb, i-phenolphthalein).
  • Burette.
  • I-conical flask.
  • Amanzi acwecwe.
  • I-stirrer noma i-stirrer magnetic.
  • Ibhalansi yokuhlaziya.
  • imitha ye-pH noma iphepha lenkomba.

3. Inqubo:

  1. Ukulungiselela Isampula:
    • Kala inani elithile lesampula ye-CMC ngokunembile usebenzisa ibhalansi yokuhlaziya.
    • Chaza isampula ye-CMC kumthamo owaziwayo wamanzi acwecwe ukuze ulungise isisombululo sokugxilisa ingqondo okwaziwayo.Qinisekisa ukuxuba okuphelele ukuze uthole isixazululo se-homogeneous.
  2. I-Titration:
    • I-Pipette ivolumu elinganisiwe yesisombululo se-CMC ibe yiflaski eyikholi.
    • Engeza amaconsi ambalwa e-acid-base indicator (isb., phenolphthalein) eflaskini.Inkomba kufanele ishintshe umbala ekugcineni kwe-titration, ngokuvamile ezungeze i-pH 8.3-10.
    • Titrate isixazululo se-CMC ngesisombululo esijwayelekile se-NaOH esivela ku-burette ngokunyakazisa njalo.Rekhoda ivolumu yesisombululo se-NaOH esingeziwe.
    • Qhubeka ne-titration kuze kufinyelelwe ekugcineni, okuboniswa ukushintsha kombala okuqhubekayo kwenkomba.
  3. Ukubala:
    • Bala i-DS ye-CMC usebenzisa ifomula elandelayo:
    ��=���NaOH�CMC

    DS=mCMCV×N×MNaOH

    Kuphi:

    • ��

      DS = Iziqu Zokushintshwa.

    • V = Umthamo wesisombululo se-NaOH esisetshenzisiwe (ngamalitha).

    • N = Okujwayelekile kwesixazululo se-NaOH.

    • �NaOH

      MNaOH = Isisindo se-Molecular NaOH (g/mol).

    • �CMC

      mCMC = Inqwaba yesampula ye-CMC esetshenzisiwe (ngamagremu).

  4. Ukutolika:
    • I-DS ebaliwe imele inani elimaphakathi lamaqembu e-carboxymethyl ngeyunithi ngayinye ye-glucose ku-molecule ye-CMC.
    • Phinda ukuhlaziya izikhathi eziningi futhi ubale i-DS emaphakathi ukuze uqinisekise ukunemba nokuthembeka kwemiphumela.

4. Okucatshangwayo:

  • Qinisekisa ukulinganiswa okufanele kwemishini kanye nokumiswa kwama-reagents ukuze uthole imiphumela enembile.
  • Phatha isisombululo se-NaOH ngokucophelela njengoba sidala futhi singabangela ukusha.
  • Yenza i-titration ngaphansi kwezimo ezilawulwayo ukuze unciphise amaphutha nokuhlukahluka.
  • Qinisekisa indlela usebenzisa izilinganiso zereferensi noma ukuhlaziya okuqhathanisayo nezinye izindlela eziqinisekisiwe.

Ngokulandela le ndlela ye-titration, izinga lokushintshwa kwe-sodium carboxymethyl cellulose (CMC) linganqunywa ngokunembile, linikeze ulwazi olubalulekile lokulawula ikhwalithi kanye nezinjongo zokwakheka ezimbonini ezihlukahlukene.


Isikhathi sokuthumela: Mar-07-2024
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