Yaa Decision Of Copper Numbers Of Cellulosic Materials
Friday 21 December 2018
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Determination of Copper Numbers of Cellulosic Materials
Ahsanul Islam Shawn
Textile Engineer
Rahim Textile Mills Ltd.
University of South Asia, Bangladesh
Email: eng.ahsanulislam@gmail.com
Ahsanul Islam Shawn
Textile Engineer
Rahim Textile Mills Ltd.
University of South Asia, Bangladesh
Email: eng.ahsanulislam@gmail.com
Copper number:
As started before inward the department 3.5.5 that cotton is oxidized yesteryear H2O2 together with oxycellulose is produced. Oxycellulose having aldehyde equally functional grouping act equally a reducing agent. Thus the traditional method of estimating the marking of degradation due to oxycellulose formation is to create upward one's heed the copper number.
Copper set out is the grams of copper, which are reduced from the cupric (Cu ++) to the cuprous (Cu+) solid soil yesteryear 100gm of cellulose when it is boiled amongst Fehling’s solution or around equivalent reagent.
Determination of copper number:
Fehling’s solution is required for the estimation of copper set out 2 dissimilar solutions is required which are mixed inward equal volumes simply before use.
Preparation of Fehling’s solutions:
Two dissimilar solutions were made equally follows:
Following procedures are followed for conclusion of copper number:
Each ml of 0.1N potassium permanganate is equivalent to 0.0063 gm of copper.
Where Z is the titrate of 0.1N KMnO4 inward ml.
Copper no ------------------- ratting
Up to 0.3 --------------------- measure
Up to 0.5 --------------------- acceptable
Above 0.5 -------------------- unacceptable
Fehling’s solution is required for the estimation of copper set out 2 dissimilar solutions is required which are mixed inward equal volumes simply before use.
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| Copper set out test |
Two dissimilar solutions were made equally follows:
- 34.63 gm of crystalline copper sulphate is dissolved inward 500 ml of water.
- seventy gm of sodium hydroxide together with 173 gm of Rochelle tabular array salt are dissolved inward 500 ml of water.
Following procedures are followed for conclusion of copper number:
- 3 gm of the sample of dry out cellulose to move investigated was taken together with cutting into modest pieces.
- This was taken inward flask together amongst 100 ml of Fehling’s solution (50 ml of each solution) together with 200 ml of water.
- It was hence boiled for fifteen minutes
- After boiling the solution, containing the fiber together with cuprous oxide was hence filtered thorough a cintered crucible together with remainder is washed amongst boiling water.
- Fibers together amongst the retained cuprous oxide on the crucible are transferred to beaker.
- 1.5 gm of ferric alum was dissolved inward dilute sulphuric acid (10%) solution together with this was hence added to the beaker. Thus ferrous sulphate, inward an total precisely equivalent to the cuprous oxide, volition move formed inward accordance amongst the next equations:
Fe2 (SO4) three + H2O = 2 FeSO4 + H2SO4 + O
Cu2O + 2 H2SO4 + O = 2 CuSO4 + 2 H2O
- The ferrous sulphate is determined yesteryear titration amongst 0.1N potassium permanganate. Preparation of 0.1N KMnO4 is depict inward the 4.1.4 section.
- The terminate betoken of titration is determined when the pinkish color retains for thirty seconds
Each ml of 0.1N potassium permanganate is equivalent to 0.0063 gm of copper.
Copper set out = Z * 33.33 * 0.0063
Where Z is the titrate of 0.1N KMnO4 inward ml.
Copper no ------------------- ratting
Up to 0.3 --------------------- measure
Up to 0.5 --------------------- acceptable
Above 0.5 -------------------- unacceptable