HG/T 2712-1995 Determination of viscosity of liquid and solution phenolic resins
Some standard content:
Chemical Industry Standard of the People's Republic of China
Determination of viscosity of liquid and solution phenolic resins
HG / T 2712 95
This standard is equivalent to the main method 1 in the international standard IS09371-1990 "Determination of viscosity of plastic liquid phenolic resins or phenolic resin solutions",
-Ubbelohde capillary viscometer method,
1 Subject content and scope of application
This standard specifies the method for determining the kinematic viscosity of liquid and solution phenolic resins using Ubbelohde capillary viscometer. This standard is applicable to the determination of resins with kinematic viscosity of 2 to 10000 mm/s. Kinematic viscosity is a property of Newtonian liquids. Since resins and resin solutions are non-Newtonian liquids, the viscosity obtained by this method is not suitable. It will be a kind of apparent auspicious
When the sample is a solution, the solvent used and the selected concentration should be agreed upon by the relevant parties 2 Reference standard
GB/T1632 Determination of viscosity and intrinsic viscosity of dilute solution of compound ZBY275 Type and basic dimensions of drop-type precision experimental glass thermometer 3 Principle
Under precisely controlled temperature, measure the time required for a certain volume of liquid resin or resin solution stored in a glass viscometer ball to flow through a calibrated capillary driven by a reproducible gravity pressure head. 4 Only instrument
4.1 Ubbelohde viscometer, as shown in Figure 1. Table 1 lists the approximate values of the instrument constant c, the capillary diameter and the corresponding viscosity range. When the instrument constant is 0.01~0.05mm*/s, the volume of ball c is 4mL; when the instrument constant is 0.1~1.0mm/s, the volume of ball c is 5mL; when the instrument constant is 3.0~10.0mm/s, the volume of ball c is 6mL Note: The OC type very liquid Ubbelohde capillary viscometer specified in GB/T1632 can also be used. Adoption instructions: This standard is equivalent to only one method in ISO937[--1990, approved by the Ministry of Chemical Industry of the People's Republic of China on May 5, 1995 and implemented on January 1, 1996
Approximate c value
HG/T 2712-95
Figure 1 Ubbelohde viscometer
Table viscometer dimensions, approximate instrument band value c and kinematic viscosity range Capillary inner diameter
c Ball volume
Kinematic viscosity range
10 ~50
Approximate solution value
HG /T 2712—95
Continued Table 1
Capillary inner diameter
C ball volumewwW.bzxz.Net
Kinematic viscosity range
20~100
60~300
100~500
200~1000
600~3000
1 000 ~5 000
2 000~10 000
The viscometer is fixed on a viscometer stand that can hold various tubes. The stand keeps the viscometer in the vertical state required by this method. The injection scales (G and H) of ball A indicate the minimum and maximum injection plates to ensure the pressure required for correct operation. 4.2 Constant temperature bath. The design requires that when the viscometer is measured in the bath, the ball c above the capillary is at least 30mm below the bath surface, and the surface viscometer tube and thermometer can be seen. The viscometer stand is used to keep the tube vertical within the range of 1. The constant temperature bath is equipped with a heater and a stirrer. The entire length of the viscometer and all the tubes can be maintained at 23±1℃. 4.3 Filter funnel with sand core bottom and medium porosity (average pore size 40-50um) 4.4 Stopwatch, accurate to 0.1s.
.4.5 Long rod thermometer, scaled from 20 to 45℃, with a graduation value not greater than 0.1℃. Fu Tai ZBY275.4.6 Vacuum device, through the top of the N tube, raise the liquid level of the resin or resin solution to the horizontal height in the ball c required by this test.
5 Test steps
5.1 Calibration of the viscometer
The viscometer should be calibrated before the first use and regularly thereafter (see Appendix A). The instrument constants are usually supplied with the viscometer, but it is best to check them. 5.2 Cleaning of the viscometer
When first used, clean the viscometer with an acid cleaning solution, and then regularly. At room temperature, the cleaning solution should remain in the viscometer for at least 12 hours. Of course, at higher temperatures, this time can be shorter. Then drain the viscometer, first with deionized water, then with acetone, and finally dry the viscometer with a filtered dry air stream. The thoroughly cleaned viscometer can be rinsed with a suitable high-volatility solvent between measurements. The viscometer can be blown dry by passing a slow stream of dry, filtered air for 2 minutes, or until no trace of solvent is left. 5.3 Determination of viscosity
Inject the resin or resin solution into the viscometer. The viscometer is tilted 30° and the ball A is kept under the capillary tube (see Figure 1). Through the filter funnel, a sufficient amount of liquid is injected into the L tube so that when the viscometer is vertical, its liquid level is between the injection wave scale lines G and H. The bottom U-shaped tube (P) of the viscometer should be completely filled without leaving any bubbles. Submerge the viscometer in a constant temperature bath and use a viscometer stand to keep the viscometer vertical.
The temperature of the thermostatic bath is kept at 23±0.1℃ for a period of time, so that the viscometer filled with liquid reaches the temperature of the constant overflow bath, plug the mouth of the M tube with a finger, and draw suction at the N tube until the liquid reaches the center of the ball D of the N tube. Remove the suction from the N tube, remove the finger from the M tube and immediately plug it on the N tube until the liquid in the M tube is completely discharged from the lower end of the capillary (R), then remove the finger from the N arm, and use a stopwatch to measure the flow time from the bottom of the liquid surface through the upper edge of the E scale line to the upper edge of the F scale line, and read to .0,18. The flow time needs to be at least 200s. If it is less than 200s, select a capillary and reassemble the viscometer and repeat the test. Retest with different test materials. Result expression
The kinematic viscosity is expressed in mm2/g:
yac(tAt)
Where: c
Viscometer constant, mn/s2 (see A1):
-flow time, s;
-flow time correction value, ε (see A2)
Calculate the arithmetic mean of the two measurements. If the relative value difference is greater than 5%, then re-measure with different test materials. 7 Test report
The test report includes the following items:
Indicate reference to this industry standard:
Complete identification of the tested resin sample;||t t||When the sample is a solvent, the solvent used and the selected concentration: test temperature:
Test results;
Test date
HG/T2712-95
Appendix A
Calibration of Ubbelohde viscometer
(Supplement)
Each viscometer needs to be calibrated before use, because even if multiple viscometers may have similar instrument constants, they also have different geometric shapes, so kinetic energy correction is required. A 1 Determination of viscometer constant c
At 23±0.1℃, measure the flow time of the calibration liquid and measure it to 0.1s. The flow time corresponding to the viscosity of the liquid is greater than 200 s.
Under these conditions, the required kinetic energy correction can be ignored, and the viscometer constant c can be calculated using the following formula: Where:
—kinematic viscosity of the calibration liquid at 23, mm2/s; —flow time, s.
A Determination of the correction value At of the flow time of low viscosity liquids Under the sampling conditions of A1, use the same viscometer to measure the flow time, expressed in s, of at least three calibration liquids at the same temperature. They have a lower viscosity than the calibration liquid used to determine the viscometer constant, and their corresponding flow times are 60 to 200 s. Calculate At for each calibration liquid, which represents the difference between the measured flow time and the flow time without considering the loss of potential energy converted into kinetic energy. The formula is:
Where: t.—flow time, si
—kinematic viscosity of the calibration liquid, 23±0.1℃, mm2/ss-viscometer constant, mm2/s2 [see A1). Use a pair of and r values obtained for each calibration liquid to draw a curve f.) For each measured flow time 1. The ^ value of the phenolic resin sample can be determined from this curve. With the A1 value, the viscosity of the phenolic resin sample can be calculated (see 6). Additional notes:
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Chemical Method Branch of the National Plastics Standardization Technical Committee. This standard is drafted by Fudan University.
The main drafter of this standard is Ma Ruidian,
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