HG/T 2710-1995 Determination of water miscibility of liquid phenolic resins HG/T2710-1995 Standard download decompression password: www.bzxz.net

Chemical Industry Standard of the People's Republic of China
Determination of water miscibility of liquid phenolic resin
HG/T2710-95
ISO 8989—1988
This standard is equivalent to the international standard ISO8989—1988 "Determination of water miscibility of plastic liquid phenolic resin". Subject content and scope of application
This standard specifies the determination method of water and liquid phenolic resin miscibility. Water miscibility depends on the test conditions and the degree of polycondensation of the resin. Reference standards
GB12805 Laboratory glass instruments burette
ZBY275 Rod-type precision laboratory glass thermometer Types and basic dimensions 3 Principle
Determine the mass percentage of water required to cause mixing of liquid aldehyde-formaldehyde resin. Measure at a temperature of 23±0.1℃.
Add water to the resin until the mixing does not disappear for at least 30 seconds after stirring. 4 Reagents
Distilled water, or water of equivalent purity.
5.1 Beaker, 100mL or larger container, depending on the degree of miscibility of the resin in water (Note ① in 7.2). 5.2 Thermometer, short-handled capillary type, range 19～31℃, graduation value 0.1℃, in line with STC,/0. 1 / 19 /31.
of ZBY275.5.3 Electromagnetic stirrer,
5.4 Burette, nominal capacity 50mL, graduation value 0.1mL, in line with Class A requirements of GB12805.5.5 Analytical balance, sensitivity 0.01g.
6 Conditioning and test temperature
The measurement should be carried out at 23±0.1℃. Before the test, the resin and distilled water should be conditioned at this temperature. 7 Operating steps
7.1 Preliminary test
When the water solubility of the resin to be tested is unknown, a preliminary test should be carried out first to determine its approximate value. 7.2 Actual test
Based on the results of the preliminary test, take 10-50 ml of the test sample for actual test. In a 100mL beaker, weigh the test sample to an accuracy of 0.01g. Approved by the Ministry of Chemical Industry of the People's Republic of China on May 5, 1995, and implemented from January 1, 1996
HG/T 2710-95
Note: ①If the water solubility of the test sample (if its value is unknown, it is measured according to .1) exceeds 900% (m/yuan), a larger container should be used to verify whether the resin temperature is 23±0.1℃ with a thermometer. Place the beaker on an electromagnetic stirrer and use a burette to add 23±0.5% distilled water in the following steps. The first time, add about 50% of the amount of water required to reach the expected turbidity limit (that is, 50% of the amount determined in the preliminary test when the water miscibility is unknown). Subsequently, add about 10% of the expected amount each time until turbidity appears and disappears after stirring. Use a thermometer to verify that the temperature of the mixture is 23±0.1. Then, add water dropwise while stirring until the turbidity does not disappear for at least 30 seconds. Record the volume of water added (mL). Note: For some resins, the volume may be the same as the volume V (mL). It is meaningful to measure both opalescent and opaque turbidity (for the latter, the mixture becomes milky or precipitates appear). If you want to measure opaque turbidity, you must separately record the volume of water V required to produce opalescent turbidity and the volume of water V required to produce opaque turbidity. Result expression
The miscibility of the resin in water WM is expressed as mass percentage and calculated according to formula (1): V
In the formula: V—the volume of water added, mL, (assuming that the density of water at 23 o'clock is 1kg/L, that is, Vg); - the mass of the test material, g.
Note: The test result can also be expressed as a ratio: 1:x
In the formula: X=WM / 100
9 Test report
The test report should include the following items:bZxz.net
Indicate reference to this industry standard;
Complete identification of the tested resin;
Test results calculated according to 8;
Test period,
Note: If both opalescence and opacity are measured at the same time, as described in Note ② of 7.2, there should be two test results. Note:
This standard was 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 was drafted by the Shanghai Import and Export Commodity Inspection Bureau. The main drafters of this standard are Chen Li and Gu Mingliang, (1)
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