GB 5888-1986 Determination of degree of polymerization of ramie cellulose
Some standard content:
National Standard of the People's Republic of China
Testing method of degree of polymerlzationof ramle cellulose
UDC 677.151.014
GB 5888-86
This standard is the method for determining the degree of polymerization of ramie cellulose. All tests requested during production, acceptance and delivery shall be conducted in accordance with this standard. Joint samples
The test shall be conducted in accordance with the provisions of GB5881--86 "Sampling Method for Testing Physical and Chemical Properties of Ramie". Test conditions
The test must be conducted at room temperature below 25℃. 3 Test cycle
Periodic tests shall be conducted according to production needs, and each product variety shall be tested at least once a week. Inspections during acceptance and delivery shall be agreed upon by both parties.
4 Instruments and Chemicals
4.1 Glass Instruments
Ostwald Viscometer: Capillary diameter Φ0.5~0.6mmzGlass Desiccator: 150mmz
Pipette: 10ml;
Pipette: 25ml
Graduating Cylinder: 10, 100, 500mls
Beaker: 400, 1000ml;
Stopped Erlenmeyer Flask: 250ml,
Narrow-necked Bottle (brown): 500ml,
Acid Burette: 50ml;
Volume Flask: 250ml.
4.2 Weighing Instruments
Precision Analytical Balance: Sensitivity 1/10,000 gram. 4.3 Others
a. Precision glass water bath
Technical parameters
Temperature adjustment error: ±0.1℃.
Magnetic constant temperature stirrer: 150W,
Plastic bottle: 50ml,
Stopwatch: precision not less than 1/10S$
Electrical constant temperature drying oven,
Technical parameters
National Bureau of Standards 1986-01-21 Issued
Reference model
76-Ｉ type
Reference model
1986 10-01 Implementation
Temperature control range: 50~150℃,
Sensitivity: ±1℃.
f. Ear wash bulb,
g. Wide range pH test paper: pH 1～14;
h. Precision pH test paper: pH2.7～4.7;
1. Household refrigerator: 2001.
4.4 Chemicals
GB 588886
Copper sulfate (CuSO4·5H2O): content not less than 99.0%, analytically pure; Ammonia water: ammonia content 25~28%, analytically pure
Sodium hydroxide: content not less than 95%, analytically pure; Anhydrous ethylenediamine: content not less than 98%, analytically pure; Potassium iodide: content not less than 98%, chemically pure; Glacial acetic acid: content not less than 99.0%, chemically pure; Sodium thiosulfate: content not less than 98%, chemically pure; Soluble starch: chemically pure,
Ammonium thiocyanate: content not less than 98.0%, chemically pure; Sulfuric acid: content 95~98.0%, chemically pure; Nitric acid: content 65~68%, chemically pure;
Methyl yellow indicator:
Phenol indicator:
Barium fluoride: content not less than 99.0%, chemically pure. 5 Determination method
5.1 Sample preparation
Y801A type
Randomly select 4 to 6 points from the sample, take out samples weighing about 5g, extract the wax and fat, dry them, cut them into pieces (length not exceeding 1mm), place them in a constant temperature drying oven, and bake them at 105~110℃ for 20min. Take them out and cool them in a glass dryer for 15min, weigh the samples, each weighing about 40mg, a total of 3.
5.2 Sample dissolution
Put the weighed samples in plastic vials with lids, add 20~25 clean copper particles (Φ2.5mm×5mm, soak them in concentrated nitric acid and anhydrous ethylenediamine solution before use, and then wash them repeatedly with distilled water). Then add 10ml of distilled water and 10ml of 1M copper ethylenediamine solution, stir with a magnetic stirrer for 1h to dissolve the sample completely, and prepare a ramie cellulose copper ethylenediamine solution with a concentration of about 0.2g/100ml.
Measurement steps
Accurately pipette 6.5ml of ramie cellulose copper ethylenediamine solution into a calibrated, cleaned, and dried Ostwald viscometer, place it in a precision glass water bath at 25±0.1℃, and measure after half an hour of temperature equilibrium. When measuring, first use an ear-washing bulb to carefully suck the solution to be tested into the sphere at the upper end of the viscometer capillary. When the liquid level exceeds the upper mark on the sphere, release the ear-washing bulb. Start timing when the liquid level falls to the upper mark, and stop the meter when the liquid level flows out of the sphere and reaches the lower mark. Measure the outflow time, repeat three times, and take the average value. According to the same method, use the same viscometer to make a blank test, and measure the outflow time of 0.5M copper ethylenediamine pure solution for three times in a row, and take the average value.
6 Calculation method
Apply the specific coefficient method.
6.1 Calculation of relative viscosity
Relative viscosity is calculated according to formula (1):
Where: n-
-relative viscosity,
GB 5888-86
average time of ramie cellulose copper ethylenediamine solution flowing through the viscometer, s10-average time of 0.5M copper ethylenediamine pure solution flowing through the viscometer, SsK-correction coefficient of the viscometer.
6.2 Calculation of characteristic viscosity
According to the measured nr value, the [n]·c value is obtained from the conversion table of n and [n]·C for determining the degree of polymerization of ramie cellulose in Appendix A (supplement).
Calculate the intrinsic viscosity according to formula (2):
Where: 【n】
Intrinsic viscosity:
Actual concentration of ramie cellulose copper ethylenediamine solution, g/100ml. 6.3 Calculate the degree of polymerization DP of ramie cellulose
The degree of polymerization of ramie cellulose is calculated according to formula (3): DP= 156 【n]
Where: DP——degree of polymerization of ramie cellulose. 6.4 Rounding of numbers
（2）
（3）
The degree of polymerization is an integer value. The rounding of numbers shall be carried out in accordance with the number rounding rules (supplement) in Appendix C of GB1.1-81 "General Provisions for the Preparation of Standards in the Guidelines for Standardization Work".
GB5888—86bZxz.net
Appendix A
Conversion table of n, and [n]·C for determining the degree of polymerization of ramie cellulose (supplement)
(n]·C
.2.805
GB 5888-86
.2.968
.3.094
GB 5888--86
.3.223
GB 5888---86
Appendix B
1 Preparation, calibration and adjustment of 1M copper ethylenediamine solution (supplement)
B.11 Preparation of 1M copper ethylenediamine solution
Weigh 100g analytical pure copper sulfate (CuSO4·5H2O) and place it in a 1000ml beaker containing 800ml distilled water and heat to boiling. After the copper sulfate is completely dissolved, slowly add about 58ml of concentrated ammonia water while stirring with a magnetic stirrer, so that the sulfuric acid solution changes from the initial blue to emerald green and finally to blue. Continue stirring for 20 minutes and let it stand to allow it to precipitate. At this time, use a wide range pH test paper to test that the upper clear liquid should be weakly alkaline (if there is too much ammonia water, it can be neutralized with 1:5 sulfuric acid). Pour off the upper clear liquid and repeatedly wash the precipitate using the tilting method, first wash it 4 times with hot distilled water, and then wash it several times with cold distilled water. Add about 400ml of distilled water each time while stirring with the stirrer, and stir for 10 min and then let it stand. When washing is continued until there is no sulfate ion in the clear solution tested with 10% barium chloride solution. Finally, add enough distilled water to the precipitate to make the total volume 600ml, place it in a refrigerator, and cool it to below 10℃. After taking it out, slowly add 340ml of 20% sodium hydroxide solution while stirring, and then repeatedly wash the copper hydroxide precipitate by tilting method until the clear solution is colorless when tested with phenol anhydride (about 13 times). Then use enough distilled water to transfer the copper hydroxide precipitate into a brown narrow-necked bottle to make the total volume 250ml, and then add 40g of anhydrous ethylenediamine (about 45ml for 98% content), shake it and let it stand for 1 to 2 days. Slowly pour the upper clear liquid into a measuring cylinder and record the volume, and transfer it to another brown bottle (discard the black precipitate in the original brown bottle) for calibration. B. Calibration of 21M copper ethylenediamine solution
B.2.1 Calibration of copper concentration
Use a 25ml pipette to draw the solution to be tested into a 250ml volumetric flask, dilute it to the scale with distilled water, then draw 25ml of the diluted solution into a 250ml stoppered conical flask, add 3g solid potassium iodide and 50ml 2N acetic acid, cover the stopper tightly, shake the hook and place in a dark place for 5min, then titrate with 0.1000N sodium thiosulfate solution until the brown color almost disappears, add 5ml 10.2% starch solution, shake well and continue to titrate until the blue color almost disappears, add 1g ammonium thiocyanate, shake well and continue to titrate until the blue color just disappears, which is the end point, and do this 3 times in total. Calculate according to formula (B1) and take the average value:
Where: y
-molar concentration of copper, M,
N2 equivalent concentration of sodium thiosulfate standard solution, N, V2
titration consumption of sodium thiosulfate standard solution, ml; -volume of copper ethylenediamine solution used for titration (2.5ml), ml. B.2.2 Calibration of ethylenediamine concentration
Use a 25ml pipette to draw the above dilution into a 250ml conical flask, add 15ml of distilled water and 4 drops of 0.1% methyl yellow indicator, and titrate with 0.5000N sulfuric acid standard solution until the solution to be tested changes from dark blue to light green, and finally to light red as the end point (pH=3.05 at this time). Do this 3 times in total.
Calculate according to formula (B2) and take the average value.
Wherein: X~-- ethylenediamine molar concentration, M, Ni
NiVi - 2 n2V2
equivalent concentration of sulfuric acid standard solution, N;
titration consumption of sulfuric acid standard solution, ml. B.3 Adjustment of copper ethylenediamine solution
The ratio of x and y in the copper ethylenediamine solution is required to be R=--=2.00±0.04, where y=1.00±0.02M. If R<1.96, y>1.02M, it means that the amount of ethylenediamine and water in the solution is insufficient, which can be calculated as follows: 70
(B２)
GB5888-86
B.3.1 The amount of ethylenediamine that needs to be added to the copper ethylenediamine solution Vz is generally = (2 y-×) 6.0
Wherein: Vz is the amount of ethylenediamine that needs to be added, ml; A
is the percentage of ethylenediamine solution, %; V--the volume of copper ethylenediamine solution remaining in the brown bottle, ml. B.3.2 The total amount of copper ethylenediamine adjusted
Vtotal=yV
Wherein: Vtotal-
-the total amount of copper ethylenediamine adjusted, ml.
B.3.3 The amount of distilled water to be added
V water = V total (Vz diamine + V)
·(B4)
- the amount of distilled water added, ml.
Where: V*-
If R>2.04, y<0.98M, it means that the copper content in the copper ethylenediamine solution is insufficient, and sufficient copper hydroxide should be added. When R<1.96, recalibrate and calculate according to the above method to make adjustments. B.4 Example
Prepare 215ml of 1M copper ethylenediamine solution, consume 22.43ml of 0.1200N sodium thiosulfate standard solution and 28.30ml of 0.5549N sulfuric acid standard solution in the titration, and adjust the copper content and ethylenediamine concentration in the copper ethylenediamine solution. According to the measurement results, N2=0.1200N, V2=22.43ml, V=2.5ml, N2=0.5549N, Vl=28.30ml. y
N2V2_ 0.1200 ×22.43-
:1.08M >1.02M
NiV1-2N2V3=0.5549 ×28.30 - 2 ×0.1200 ×22.432V
= 1.91<1.96
This shows that the content of ethylenediamine and distilled water in the copper ethylenediamine solution is insufficient. Given that x = 2.06M;
J = 1.08M,
V=178ml (original 215ml, 25ml used for titration, 12ml used for washing the pipette), A=98 (the content of ethylenediamine solution is 98%). a. Amount of ethylenediamine to be added:
Total volume of copper ethylenediamine solution:
Vethylenediamine=(2y-x)
= (2×1.08-2.06)×-
Vtotal=yV=1.08×178=192ml
Amount of distilled water to be added
GB5888—86
Vwater=Vtotal-(Vethylenediamine+V)
=192-(1.09+178)
=13ml
Accurately add 1.1ml of ethylenediamine solution and 13ml of distilled water to the copper ethylenediamine solution, shake and let stand for 2h, then perform a second titration. Result:
N2 = 0.1200N, V2 - 21.06ml
N =0.5549N, V1 = 27.33ml
Calculation:
y=1.01M (within the range of y=1.00±0.02M) R=
which meets the use requirements.
.8%=2.03 (within the range of R=2.00±0.04) 2.05
Test report of ramie cellulose polymerization degree
Laboratory No.
Test date
Product variety
Process characteristics
Dried flax
Flax strips (balls)
Combed fiber:
Flax strips (balls)
Average polymerization degree
Analysis opinion
GB 5888—86
Appendix C
Tabular form
(reference)
Test report of polymerisation degree of ramie cellulose
Laboratory
C.2 Test record of polymerisation degree of ramie cellulose
Sampling date
Measurement date
Dried ramie
Ramie strips (balls)
Sample number
0.5M copper ethylenediamine pure solvent flowed
Instrument time to, s
0.5M copper ethylenediamine
Cellulose solution flowed
Instrument time, s
Relative viscosity nr
Table lookup【n】·C value
Specimen degree of polymerization (DP)
Average degree of polymerization (DP)
Additional notes:
Product variety
GB5888--86
Record of polymerization degree test of flax cellulose
Combed fiber
Laboratory number
Flax strips (balls)
This standard was proposed by the Ministry of Textile Industry of the People's Republic of China and is under the jurisdiction of the Standardization Research Institute of the Ministry of Textile Industry. This standard was drafted by the East China Textile Institute and jointly drafted by Zhuzhou Ramie Textile Printing and Dyeing Factory and Shanghai No. 9 Cotton Textile Factory. The main drafters of this standard are Jiang Fanchang and Shao Kuan. 7402M, indicating that the amount of ethylenediamine and water in the solution is insufficient, which can be calculated as follows: 70
(B２)
GB5888-86
B.3.1 The amount of ethylenediamine that needs to be added to the copper ethylenediamine solution Vz is generally = (2 y-×) 6.0
Wherein: Vz is the amount of ethylenediamine that needs to be added, ml; A
is the percentage of ethylenediamine solution, %;
V--the volume of copper ethylenediamine solution remaining in the brown bottle, ml. B.3.2 The total amount of copper ethylenediamine adjusted
Vtotal=yV
Wherein: Vtotal-
-the total amount of copper ethylenediamine adjusted, ml.
B.3.3 The amount of distilled water to be added
V water = V total (Vz diamine + V)
·(B4)
- the amount of distilled water added, ml.
Where: V*-
If R>2.04, y<0.98M, it means that the copper content in the copper ethylenediamine solution is insufficient, and sufficient copper hydroxide should be added. When R<1.96, recalibrate and calculate according to the above method to make adjustments. B.4 Example
Prepare 215ml of 1M copper ethylenediamine solution, consume 22.43ml of 0.1200N sodium thiosulfate standard solution and 28.30ml of 0.5549N sulfuric acid standard solution in the titration, and adjust the copper content and ethylenediamine concentration in the copper ethylenediamine solution. According to the measurement results, N2=0.1200N, V2=22.43ml, V=2.5ml, N2=0.5549N, Vl=28.30ml. y
N2V2_ 0.1200 ×22.43-
:1.08M >1.02M
NiV1-2N2V3=0.5549 ×28.30 - 2 ×0.1200 ×22.432V
= 1.91<1.96
This shows that the content of ethylenediamine and distilled water in the copper ethylenediamine solution is insufficient. Given that x = 2.06M;
J = 1.08M,
V=178ml (original 215ml, 25ml used for titration, 12ml used for washing the pipette), A=98 (the content of ethylenediamine solution is 98%). a. Amount of ethylenediamine to be added:
Total volume of copper ethylenediamine solution:
Vethylenediamine=(2y-x)
= (2×1.08-2.06)×-
Vtotal=yV=1.08×178=192ml
Amount of distilled water to be added
GB5888—86
Vwater=Vtotal-(Vethylenediamine+V)
=192-(1.09+178)
=13ml
Accurately add 1.1ml of ethylenediamine solution and 13ml of distilled water to the copper ethylenediamine solution, shake and let stand for 2h, then perform a second titration. Result:
N2 = 0.1200N, V2 - 21.06ml
N =0.5549N, V1 = 27.33ml
Calculation:
y=1.01M (within the range of y=1.00±0.02M) R=
which meets the use requirements.
.8%=2.03 (within the range of R=2.00±0.04) 2.05
Test report of ramie cellulose polymerization degree
Laboratory No.
Test date
Product variety
Process characteristics
Dried flax
Flax strips (balls)
Combed fiber:
Flax strips (balls)
Average polymerization degree
Analysis opinion
GB 5888—86
Appendix C
Tabular form
(reference)
Test report of polymerisation degree of ramie cellulose
Laboratory
C.2 Test record of polymerisation degree of ramie cellulose
Sampling date
Measurement date
Dried ramie
Ramie strips (balls)
Sample number
0.5M copper ethylenediamine pure solvent flowed
Instrument time to, s
0.5M copper ethylenediamine
Cellulose solution flowed
Instrument time, s
Relative viscosity nr
Table lookup【n】·C value
Specimen degree of polymerization (DP)
Average degree of polymerization (DP)
Additional notes:
Product variety
GB5888--86
Record of polymerization degree test of flax cellulose
Combed fiber
Laboratory number
Flax strips (balls)
This standard was proposed by the Ministry of Textile Industry of the People's Republic of China and is under the jurisdiction of the Standardization Research Institute of the Ministry of Textile Industry. This standard was drafted by the East China Textile Institute and jointly drafted by Zhuzhou Ramie Textile Printing and Dyeing Factory and Shanghai No. 9 Cotton Textile Factory. The main drafters of this standard are Jiang Fanchang and Shao Kuan. 7402M, indicating that the amount of ethylenediamine and water in the solution is insufficient, which can be calculated as follows: 70
(B２)
GB5888-86
B.3.1 The amount of ethylenediamine that needs to be added to the copper ethylenediamine solution Vz is generally = (2 y-×) 6.0
Wherein: Vz is the amount of ethylenediamine that needs to be added, ml; A
is the percentage of ethylenediamine solution, %;
V--the volume of copper ethylenediamine solution remaining in the brown bottle, ml. B.3.2 The total amount of copper ethylenediamine adjusted
Vtotal=yV
Wherein: Vtotal-
-the total amount of copper ethylenediamine adjusted, ml.
B.3.3 The amount of distilled water to be added
V water = V total (Vz diamine + V)
·(B4)
- the amount of distilled water added, ml.
Where: V*-
If R>2.04, y<0.98M, it means that the copper content in the copper ethylenediamine solution is insufficient, and sufficient copper hydroxide should be added. When R<1.96, recalibrate and calculate according to the above method to make adjustments. B.4 Example
Prepare 215ml of 1M copper ethylenediamine solution, consume 22.43ml of 0.1200N sodium thiosulfate standard solution and 28.30ml of 0.5549N sulfuric acid standard solution in the titration, and adjust the copper content and ethylenediamine concentration in the copper ethylenediamine solution. According to the measurement results, N2=0.1200N, V2=22.43ml, V=2.5ml, N2=0.5549N, Vl=28.30ml. y
N2V2_ 0.1200 ×22.43-
:1.08M >1.02M
NiV1-2N2V3=0.5549 ×28.30 - 2 ×0.1200 ×22.432V
= 1.91<1.96
This shows that the content of ethylenediamine and distilled water in the copper ethylenediamine solution is insufficient. Given that x = 2.06M;
J = 1.08M,
V=178ml (original 215ml, 25ml used for titration, 12ml used for washing the pipette), A=98 (the content of ethylenediamine solution is 98%). a. Amount of ethylenediamine to be added:
Total volume of copper ethylenediamine solution:
Vethylenediamine=(2y-x)
= (2×1.08-2.06)×-
Vtotal=yV=1.08×178=192ml
Amount of distilled water to be added
GB5888—86
Vwater=Vtotal-(Vethylenediamine+V)
=192-(1.09+178)
=13ml
Accurately add 1.1ml of ethylenediamine solution and 13ml of distilled water to the copper ethylenediamine solution, shake and let stand for 2h, then perform a second titration. Result:
N2 = 0.1200N, V2 - 21.06ml
N =0.5549N, V1 = 27.33ml
Calculation:
y=1.01M (within the range of y=1.00±0.02M) R=
which meets the use requirements.
.8%=2.03 (within the range of R=2.00±0.04) 2.05
Test report of ramie cellulose polymerization degree
Laboratory No.
Test date
Product variety
Process characteristics
Dried flax
Flax strips (balls)
Combed fiber:
Flax strips (balls)
Average polymerization degree
Analysis opinion
GB 5888—86
Appendix C
Tabular form
(reference)
Test report of polymerisation degree of ramie cellulose
Laboratory
C.2 Test record of polymerisation degree of ramie cellulose
Sampling date
Measurement date
Dried ramie
Ramie strips (balls)
Sample number
0.5M copper ethylenediamine pure solvent flowed
Instrument time to, s
0.5M copper ethylenediamine
Cellulose solution flowed
Instrument time, s
Relative viscosity nr
Table lookup【n】·C value
Specimen degree of polymerization (DP)
Average degree of polymerization (DP)
Additional notes:
Product variety
GB5888--86
Record of polymerization degree test of flax cellulose
Combed fiber
Laboratory number
Flax strips (balls)
This standard was proposed by the Ministry of Textile Industry of the People's Republic of China and is under the jurisdiction of the Standardization Research Institute of the Ministry of Textile Industry. This standard was drafted by the East China Textile Institute and jointly drafted by Zhuzhou Ramie Textile Printing and Dyeing Factory and Shanghai No. 9 Cotton Textile Factory. The main drafters of this standard are Jiang Fanchang and Shao Kuan. 7405
Test report of polymerisation degree of ramie cellulose
Laboratory No.
Testing date
Product variety
Processing characteristics
Dried ramie
Ramie strips (balls)
Combed fibre:
Ramie strips (balls)
Average polymerisation degree
Analysis and opinion
GB 5888—86
Appendix C
Tabular form
(reference)
Test report of polymerisation degree of ramie cellulose
Laboratory
C.2 Test record of polymerisation degree of ramie cellulose
Sampling date
Measurement date
Dried ramie
Ramie strips (balls)
Sample number
0.5M copper ethylenediamine pure solvent flowed
Instrument time to, s
0.5M copper ethylenediamine
Cellulose solution flowed
Instrument time, s
Relative viscosity nr
Table lookup【n】·C value
Specimen degree of polymerization (DP)
Average degree of polymerization (DP)
Additional notes:
Product variety
GB5888--86
Record of polymerization degree test of flax cellulose
Combed fiber
Laboratory number
Flax strips (balls)
This standard was proposed by the Ministry of Textile Industry of the People's Republic of China and is under the jurisdiction of the Standardization Research Institute of the Ministry of Textile Industry. This standard was drafted by the East China Textile Institute and jointly drafted by Zhuzhou Ramie Textile Printing and Dyeing Factory and Shanghai No. 9 Cotton Textile Factory. The main drafters of this standard are Jiang Fanchang and Shao Kuan. 7405
Test report of polymerisation degree of ramie cellulose
Laboratory No.
Testing date
Product variety
Processing characteristics
Dried ramie
Ramie strips (balls)
Combed fibre:
Ramie strips (balls)
Average polymerisation degree
Analysis and opinion
GB 5888—86
Appendix C
Tabular form
(reference)
Test report of polymerisation degree of ramie cellulose
Laboratory
C.2 Test record of polymerisation degree of ramie cellulose
Sampling date
Measurement date
Dried ramie
Ramie strips (balls)
Sample number
0.5M copper ethylenediamine pure solvent flowed
Instrument time to, s
0.5M copper ethylenediamine
Cellulose solution flowed
Instrument time, s
Relative viscosity nr
Table lookup【n】·C value
Specimen degree of polymerization (DP)
Average degree of polymerization (DP)
Additional notes:
Product variety
GB5888--86
Record of polymerization degree test of flax cellulose
Combed fiber
Laboratory number
Flax strips (balls)
This standard was proposed by the Ministry of Textile Industry of the People's Republic of China and is under the jurisdiction of the Standardization Research Institute of the Ministry of Textile Industry. This standard was drafted by the East China Textile Institute and jointly drafted by Zhuzhou Ramie Textile Printing and Dyeing Factory and Shanghai No. 9 Cotton Textile Factory. The main drafters of this standard are Jiang Fanchang and Shao Kuan. 74
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