HG/T 2627-1994 Determination of viscosity and intrinsic viscosity of dilute solutions of methyl methacrylate polymers
Some standard content:
Chemical Industry Standard of the People's Republic of China
HG/T 2627 -- 94
Methyl methacrylate polymers
Determination of viscosity of dilute solution and intrinsic viscosity
Published on April 13, 1994
Ministry of Chemical Industry of the People's Republic of China
Implementation on January 1, 1995
Chemical Industry Standard of the People's Republic of China
Methyl methacrylate polymers
Determination of viscosity of dilute solution and intrinsic viscosity
HG/T2627—94
This standard is equivalent to the international standard ISO1628/6-1990 "Determination of viscosity and intrinsic viscosity of plastics Part 6: Methyl methacrylate Polymer", bZxz.net
1 Subject content and scope of application
This standard specifies the method for determining the dilute solution viscosity and intrinsic viscosity of methyl methacrylate polymer molding and extrusion materials. This standard is applicable to methyl methacrylate (MMA) homopolymers, copolymers and their mixtures, containing at least 80% (m/m) methyl methacrylate in the mixture. It may or may not contain additives. 2 Reference standards
GB/T1632 Determination of dilute solution viscosity and intrinsic viscosity of polymers 3 Principle
Measure the flow time of the solvent and the polymer solution of the solvent with the indicated liquid concentration at 25±0.05℃. The viscosity number and the intrinsic viscosity are calculated from the flow time and solution concentration measured above, and the viscosity number VN is expressed in mL/g.
Where: - dynamic viscosity of the test solution, mPa·s; - dynamic viscosity of the solvent, mPa*s
c - concentration of the polymer solution, μg/mL,
If the densities p and p of the solution and solvent differ slightly, then the and n in formula (1) can be replaced by the kinematic viscosities and a of the solution and solvent. Unit: mm/s.
4 Reagents
Chloroform (analytical grade), stored in a brown bottle, stored in a dark place, 5 Instruments
See Chapter 4 and Table B1 of GB/T1632,
5.1 Capillary viscometer, according to the 0C type suspension Ubbelohde capillary viscometer in GB/T1632, the inner diameter of the capillary is 0.36mm, the measuring ball volume is 2mL, z)
Instructions: 1) ISO【628/6 uses ethanol with a content of less than 1% (☆/cut) as a stabilizer, 2】ISO【6286 also uses MI type viscometer, approved by the Ministry of Chemical Industry of the People's Republic of China on April 13, 1994 and implemented on January 1, 1995
HG/T 2627—
Any other viscometer that can produce the same result can be used, but in case of dispute, this type of viscometer must be used. The calibration of the viscometer used shall be carried out according to Appendix A. 5.2 Stopwatch, readable to 0.1s.
5.3 Constant temperature bath, capable of maintaining at 25±0.05℃. 5.4 Volumetric flask, with ground glass, 100mL. s. Balance, sensitivity 0.1 mg.
5.6 Fritted glass funnel, No. 2,
5.7 Pulsator
Sample solution
Weigh 0.26±0.005g of a sample that can reflect the material properties (weighed to 0.1mg) and place it in a volumetric flask (5.4), add 50mL of chloroform (4), shake to dissolve completely, then dilute to the scale with 201C chloroform, pry again, and set aside. For polymers containing thickening additives, the solution preparation process needs to be changed. This change must be approved by the relevant Acceptable by all parties. For materials containing pigments and (or) special additives, additional samples should be weighed so that 100 mL of the test solution contains 0.26 g of methyl methacrylate.
7 Test steps
Inject chloroform or the test solution directly into the viscometer through a sintered glass funnel (5.6). At 25±0.05℃, measure the flow time of the solvent and the test solution through the same viscometer 3 to 5 times and take the arithmetic mean. For OC type viscometer, if the maximum difference in flow time exceeds 0.2 5, then the viscometer must be cleaned with solvent, dried, and re-measured with the same test solution. 3 If the viscometer used is different from the provisions of this standard, the above test steps can be appropriately modified. 8 Calculation of test results
Calculate the viscosity number (VN) mL/g according to formula (2): VN →
Where:
- kinematic viscosity of the test solution, m2/s;
o- kinematic viscosity of the solvent, mm2/s;
arithmetic mean of the flow time of the test solution, s;
- arithmetic mean of the flow time of the solvent, s; test solution concentration, g/nL;
At-- kinetic energy correction of r (see Appendix A);
-, kinetic energy correction of (see Appendix A).
Note: Formula (2) is based on Formula (5) in GB/T1632, but introduces kinetic energy correction, which is for specific specifications of viscometers. To obtain accurate results, it is necessary to use a viscometer with a smaller capillary inner diameter. At this time, the kinetic energy correction time is less than 0.2% of the flow time, which is similar to the result calculated by formula (3) provided in GB/T1632 and formula (2). VN
Instructions for use: 31 is the same as Instructions for use 2)t.
Test report
See Chapter 9 of GB/T 1632
HG/T 2627 -
HG / T 2627 - 94
Appendix A
Calibration of viscometer
(Supplement)
A1 Experience has shown that the high precision required for determining the viscosity of methyl methacrylate homopolymer or copolymer solutions cannot always be obtained from commercially available Ubbelohde viscometers. This is due to slight irregularities in the capillaries. It is therefore recommended to verify the accuracy of the viscometer with the aid of a calibration liquid of known kinematic viscosity.
A 2 Viscometer constant K
Use analytical grade n-undecane to pass through a viscometer 3 to 5 times at 25°C. The average flow time t is determined as shown in Article 7.2 of GB/T 1632. Calculate the viscometer constant K according to formula (A1): K=
Where:
The kinematic viscosity of n-undecane is 1.467:5mm2/s at 25°C. Note: The density of n-undecane at 25°C is p=0.7365g/mL. A 3 Kinetic energy correction Ata and At
If the kinetic energy correction is less than 0.2% of the flow time, it can be ignored. The flow time of OC type Ubbelohde viscometer is greater than 270s, which can meet the requirements. If the flow time is less than the above requirements, the following low viscosity liquids should be used as standards to correct the viscometer for kinetic energy: 1. Dichloromethane (analytical pure): Vz5r=0.3142mm2/sP2sc = 1. 316 3 g / mL
2. Trichloroethylene (analytical pure): V2sE=0. 369 3 mm2/ B, P2s = 1. 4555 g / rnL
3. Tetrachloroethylene (analytical pure): V2st=0.5257mm/s, P2s = 1. 614 4 g /mL
Measure the flow time of each calibration liquid for 3 to 5 seconds, and calculate the kinetic energy correction of each liquid according to formula (A2): AtA=t,
Where: 1,:—\-the flow time of the ith calibration liquid, =siK
kinematic viscosity of the ith calibration liquid, mm2/s; viscometer constant, mm2/s
According to formula (A3), linear interpolation is made between the flow times t., and 1.> of the two calibration liquids i=1 and i-2 (see Figure A1), and the kinetic energy correction 4to of the flow time t of the solvent chloroform is obtained: An
HG/ T 2627 -
In the same way, linear interpolation is made between t and t according to formula (A4) to obtain the kinetic energy correction At of the flow time t of the test solution: At = At.
Figure A1. Relationship between kinetic energy correction and reciprocal flow time Appendix B
Reciprocal flow time
Determination of intrinsic viscosity
(Supplement)
Using formula (B1), the intrinsic viscosity of methyl methacrylate polymer solution can be obtained. One-point method:
Where: ——dynamic viscosity of solution, mPa·s: no——dynamic viscosity of solvent, mPa·s: ——concentration of compound solution, zone/mL.
Additional Notes:
HG/ T2627 -
This standard was proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of the Chemical Method Branch of the National Technical Committee for Plastic Standardization. This standard was drafted by Shanghai Fudan University, and the main drafters of this standard were Ma Ruizhong and Zhang Nianhong. People's Republic of China
Chemical Industry Standard
Methyl Methacrylate Polymer
Determination of Viscosity and Intrinsic Viscosity of Dilute Solutions
HG/T 2627 — 94
Editor Chemical Industry Standard Editorial Department
(Institute of Standardization, Ministry of Chemical Industry)
Postal Code: 100011
Instrumentation Standardization Institute, Ministry of Chemical Industry
Copyright reserved. No reproduction allowed
Format 880×12301/16 Number of Printing Sheets 10000 [First Edition, November 1994
First Printing, November 1994
Number of Printings! —500
Cost 3.00 Yuan
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