HG/T 2756-1996 Determination of gel time of phenolic resin at a given temperature by automatic measuring instrument
Some standard content:
HG / T 2756—1996
This standard is not equivalent to ISO9396:1989 "Plastics-Phenolic resins-Determination of gel time at a given temperature by automatic tester".
The instrument used in this method is consistent with that specified in ISO9396. Some technical parameters have been modified according to the actual situation in my country. The main technical differences between this standard and ISO 9396 are as follows: This standard
1 Rotation speed, r/min
2 Test tube mass, name
3 Test tube length, mm
4 Vertical reciprocating speed, s-1
5 Metal ring mass, g
Axillary resol phenolic resin
Solid resol phenolic resin
6 Sample particle size, um
22 ± 2
150±4
Not more than 400
This standard was proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China and ISO 9396
Not specified
160±4
Not specified
This standard was prepared by the Plastic Resin Products Branch of the National Plastics Standardization Technical Committee. The drafting unit of this standard is: Chengdu Organic Silicon Application Research Center of the Ministry of Chemical Industry. The main drafter of this standard is Zhao Shuzhen
ISO former
The International Organization for Standardization (ISO) is a worldwide joint organization of national standardization bodies (ISO member bodies). The work of formulating international standards is carried out by ISO technical committees. Any member body interested in a project determined by a technical committee has the right to send representatives to participate in the technical committee. Governmental or non-governmental international organizations can also participate in this work by contacting ISO. ISO and the International Electrotechnical Commission (IEC) work closely on all topics of electrotechnical standardization. The draft international standards adopted by the technical committees shall be circulated to the member bodies for voting opinions before being accepted as international standards by the ISO Council. According to the ISO working procedures, at least 75% of the member bodies shall vote in favor for the vote to be valid. International Standard ISO9396 is developed by ISO/TC61 Plastics Technical Committee14
1 Scope
Chemical Industry Standard of the People's Republic of China
Determination of Gel Time of Phenolic Resin at a Given Temperature by Automatic Determination Instrument
HG / T 2756 -- 1996
neqISO 9396:1989
This standard specifies the method for determining the gel time of phenolic resin at given temperatures of 100, 130 and 150°C by automatic determination instrument.
This standard specifies two methods using two determination instruments: a) Method A drives the glass rod to rotate: b) Method B drives the piston to reciprocate vertically. The two methods are applicable to the following types of phenolic resins: liquid resol phenolic resin (method A and method B); ~ linear phenolic resin solution containing hexamethylenetetramine (HMTA), the solvent boiling point must be higher than the test temperature (method A): solid resol phenolic resin with low baking point (method B). Powdered resins with short gel time, such as mixtures of linear phenolic resin and HMTA, are not suitable for this determination. Such resins crosslink when melted and become too viscous in the test tube to obtain meaningful results. Resins containing large amounts of low-boiling solvents are particularly unsuitable for this determination. Boiling and evaporation will occur when the resin solidifies. To determine the gel time of the resin in the presence of a catalyst, a catalyst should be added in a certain proportion, and the type of catalyst used and the treatment should be noted in the test report.
2 Sample preparation
2.1 Liquid sample of resol phenolic resin (Method A and Method B) 2.2 Solid sample of resol phenolic resin (Method B) 2.3 Dissolve the powdered resin (such as linear phenolic resin + HMTA) in ethylene glycol monoacetaldehyde at a ratio of 1:1 (m/m) below 60°C. If necessary, additional solvent can be added to completely dissolve the resin (Method A). Note {: Ethylene glycol monoacetaldehyde can plasticize the resin and prolong the gel time. 2.4 A solution of linear phenolic resin containing HMTA dissolved in a high boiling point solvent. If the solution does not contain HMTA, 10% HMTA is added based on the content of linear phenolic resin (Method A). 2.5 According to the following mass ratio, dissolve the linear phenolic resin in ethylene glycol monoethyl ether and add HMTA (Method A) 10 parts linear phenolic resin;
1 part HMTA;
11 parts ethylene glycol monoacetaldehyde
3 Method A - Rotary Stirring Tester
3.1 Principlewww.bzxz.net
During the synthesis process, the phenolic resin experiences a turning point where the viscosity suddenly increases. Approved by the Ministry of Chemical Industry of the People's Republic of China on April 15, 1996, implemented on January 1, 1997
HG/ T 2756 — 1996
The time to reach this point is measured by an automatic instrument. The glass rod (in the test tube containing the sample) is driven by a motor to rotate with a limited torque. When the viscosity of the sample suddenly increases and the glass rod stops rotating, the gel point is reached. At this time, the circuit is closed, an audible signal appears, and the time indicated by the timer is the gel time at the specified temperature (A method).
3.2 Reagents
32.1 Solvent, ethylene glycol monoethyl ether (if measured at 150°C, ethylene glycol can be used instead). 3.2.2 Solvent, ethylene glycol
3.2.3 Catalyst, finely ground hexamethylenetetramine (HMTA). Comply with GB9015-88.3.3 Instrumentation
3.3.1 Rotary gel time measuring device (see Figure 1), with a rotation speed of 2r/mim, or as agreed upon by the relevant parties, 1
1- Glass drop: 2- Test tube: 3- Liquid level in test tube 4- Determination solution: 5- Constant temperature controlled solution; 6- Liquid level in bath Figure 1 Rotary gel time measuring device
3.3.2 Constant temperature controlled bath, maximum temperature 200℃, temperature control accuracy ±0.5, solution: silicone oil density 18/cm±0.1g/cm
3.3.3 Test tube, mass 22±3g, inner diameter 16mm±0.2mm, length 150mm±4mm. 3.3.4 Balance, sensitivity 0.1g
3.3.5 Glass stand, diameter 6mm±0.5mm, length about 240mm.3.3.6 Laboratory mortar or grinder.
3.4 Operation steps
3.4.1 Weigh 5g (accurate to 0.1g) of liquid resin or resin solution in a test tube. Place the test tube on a test stand that has been partially immersed in a constant temperature bath (bath temperature 100±0.5C, 130±0.5 or 150±0.5). The sample liquid level should be 10mm below the oil bath surface. Immediately start the timer and timer.
3.4.2 Adjust the glass rod so that its end is 6mm from the bottom of the test tube. Start the motor and rotate it at a speed of 2r/min (or as agreed by the relevant parties).
3.4.3 As the viscosity of the resin increases, the distance between the two metal contact arms becomes smaller and smaller. When the resin reaches the gel point, the two metal contact arms are connected, the timer stops automatically, and the buzzer alarms. Record the gel time (accurate to 0.1min). Take out the test tube from the oil bath and turn off the buzzer from time to time. Take out the glass from the test tube and clean it with ethanol or acetone. 16
3.4:4 Use the same sample to conduct a parallel test. HG/ T 2756 - 1996
3.5 Expression of results
Calculate the arithmetic mean of the two results as the gel time, unit min. When the difference between the two measurement results is greater than 5%, the test should be repeated.
3.6 Test report
The test report should include the following contents:
Indicate in accordance with this industry standard;
Method used (Method A):
Complete identification of the sample:
Test temperature;
The average value of the two measurement results, in unit mi, accurate to 0.1min; Rotation speed.
4B Method - Vertical Reciprocating Measuring Instrument
4.1 Source
A motor is used to drive the piston placed in the test tube (containing the sample) to make vertical reciprocating motion to stir the sample. When the viscosity of the sample increases to the point where the test tube is lifted with the piston, the gel point is reached, the timer stops timing, and the gel time is recorded. 4.2 Instrumentation
4.2.1 Vertical reciprocating gel time measuring device (see Figure 2), the piston reciprocating frequency is 120 times/min, or as agreed by the parties concerned,
HG/ T 2756 - 1996
1--Electric timer: 2-Timer setting knob; 3-Applicator and timer starting device; 4-Piston driving motor 5-Plug and timer brake rod: 6-Metal ring; 7-Test tube test stand; 8-Test tube 9-Stainless steel piston: 10-Phenolic resin sample; 11-Constant control bath Figure 2 Vertical reciprocating gel time measuring device 4.2.2 Constant temperature control bath, maximum temperature 200c, temperature control accuracy ± 0.5f, surplus liquid: silicone oil density is 1 g/cm± 0.1g/cm
4.2.3 Test tube, mass 22±2g, inner diameter 16mm±0.2mm, length 150mm±4mm.4.2.4 Gold ring mass
used to determine liquid resol phenolic resin is 6.8g used to determine solid resol phenolic resin is 35g4.2.5 Balance, sensitivity is 0.1g.
4.2.6 Test sieve, in line with GB6003-85, sieve aperture is not more than 400um, 4.3 Operation steps
4.3.1 Crush the solid resin and grind it into powder. Take a sample with a particle size not greater than 400 μm for later use.-4.3.2 Weigh 5 g ± 0.1 μg of liquid resin or powdered resin in a test tube, and place the test tube on a test stand that has been partially immersed in a constant temperature bath (bath temperature 100 ± 0.5, 130 ± 0.5℃ or 150 ± 0.5℃), with the depth of the test tube being 110 mm. Note 2 Solid powdered resin is suitable for 130℃ and 150℃. 4.3.3 Immediately start the glue timer and the timer, and quickly put the metal ring on the top of the test tube to prevent the test tube from being lifted prematurely as the viscosity of the resin increases before the glue point is reached. For liquid resin, quickly put the piston into the test tube; for solid powdered resin, the piston must be put into the test tube after the resin is melted. 18
HG/T2756—1996
4. 3. 4 Adjust and fix the piston so that the end of the piston is about 6 mm from the bottom of the test tube. The piston makes vertical reciprocating motion in the test tube at a rate of 120 soft/min (or as agreed by the relevant parties). When the test tube is lifted with the piston, the resin reaches the glue point, the timer stops automatically, and the buzzer alarms. Record the gel time, accurate to 0.1min. At the same time, turn off the buzzer, remove the test tube from the oil bath, and clean it with ethanol or acetone.
4,3.3 Use the same sample to conduct a parallel test, or conduct multiple tests as agreed by the relevant parties. 4.4 Expression of results
Calculate the arithmetic mean of the two measurement results as the gel time, unit min. 4.5 Test report
The test report shall include the following contents:
Indicate that it is in accordance with this industry standard;
The method used (B method);
Complete identification of the sample;
Test temperature:
Piston movement rate:
The average value of the two measurement results, in min, accurate to 0.1 min.19
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