This standard specifies a gravimetric method for determining the amount of extractables from granular phenolic moulding materials using acetone near its boiling point. This standard is equivalent to ISO 308-1981 "Plastics - Phenolic moulding materials - Determination of acetone solubles (apparent resin content of unmolded materials)". This method is only applicable to moulding materials based on linear phenolic resins, but not to moulding materials based on resol phenolic resins, because the latter type of resins are not completely soluble in acetone. In this standard, the amount of acetone solubles is the apparent resin content. Although the extractables are mainly composed of phenolic resins and hexamethylenetetramine, there are usually other acetone soluble components (such as lubricants, colorants or natural resins from fillers), which are all calculated as resins. GB/T 4616-1984 Determination of acetone solubles (apparent resin content of unmolded materials) in phenolic moulding materials GB/T4616-1984 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of acetone --soluble matter (apparent resin content of material in the .unmoulded state) Phenolic moulding materials--Determination of acetone --soluble matter (apparent resin content of material in the .unmoulded state) UDC 678.632
GB4616—84
This standard specifies the gravimetric method for determining the amount of extracts from granular phenolic moulding materials using acetone near its boiling point. This standard is equivalent to ISO308-1981 "Plastics-Phenolic moulding materials-Determination of acetone soluble matter (apparent resin content of material in the .unmoulded state)".
1 Scope of application
This method is only applicable to moulding materials based on linear phenolic resins, but not to moulding materials based on resol phenolic resins, because the latter type of resins cannot be completely soluble in acetone. In this standard, the amount of acetone solubles is the apparent resin content. Although the extract is mainly composed of phenolic resin and hexamethylenetetramine, there are usually other acetone soluble components (such as lubricants, colorants or natural resins from fillers), which are all calculated as resin. 2 Principle
Heat and extract the acetone solubles in the granular sample, dry the extract under controlled conditions and weigh the dried extract. 3 ReagentsbZxz.net
Acetone: analytical grade.
4 Apparatus
4.1 Equipment for making the molding compound into powder or granules. 4.2 Balance, with a graduation value of 0.001g.
4.3 Extractor, as shown in the figure (filter paper can be used instead of a single-layer extraction sleeve). Issued by the National Bureau of Standards on July 30, 1984
Implementation on May 1, 1985
4.4 Drying oven, which can be controlled at about 105℃. 4.5 Desiccator.
GB4616-84
4.6 Weighing bottle with ground glass stopper.
Note: Place the filter paper, thread and weighing bottle without acetone solubles in a vacuum desiccator and dry for 24 ± 1h. 5 Sample preparation
5.1 Take a fully representative sample of the molding compound. If the molding compound is in the shape of a pre-pressed ingot, sheet, block or sheet (felt, oriented or woven), the sample should be made into powder or granular form by equipment before the test. The material should not be overheated during sample preparation to prevent resin loss. The thickness of the obtained powder or granular sample should not exceed 1.5mm, and other dimensions should not exceed 5hm. The sample should not be ground too finely, otherwise it will clump during extraction.
5.2 Dry not less than 6g of the molding compound in a vacuum oven over sulfuric acid (specific gravity 1.84) or other desiccant for 24h at room temperature. 6 Steps
6.1 Test with two dried samples (see Chapter 5). 6.2 Quickly cover the dried filter paper, wire and weighing bottle taken out of the vacuum dryer, and weigh to the nearest 0.001g. Then, weigh about 3g of the dried sample to the nearest 0.001g and place it on the filter paper. Note: To prevent the weighing bottle cap from breaking during vacuuming, it can be placed in a dryer to dry. 6.3 To prevent the molding compound from escaping, tie the filter paper containing the sample tightly and place it in the siphon cup of the extractor. Assemble the snake condenser, siphon cup and flask to which 100ml of acetone (see Chapter 3) has been added. 6.4 Adjust the heating so that the siphon action is carried out at a rate of 15 to 30 times per hour, and continue to extract for 16±0.5h. After that, vacuum dry the filter paper and the material in the filter paper over sulfuric acid (specific gravity 1.84) or other desiccant at room temperature for 24±1h, and then weigh in the same weighing bottle, accurate to 0.001g.
7 Result Expression
GB4616-84
Acetone soluble matter (apparent resin content of unmolded material) & (%) is calculated as follows: ml = m2 × 100
Where: mo-—mass of filter paper, wire and weighing bottle, g, mj-
-mass of filter paper, wire, weighing bottle and sample before extraction, g, -mass of filter paper, wire, weighing bottle and sample after extraction, g. Take the arithmetic mean of the values ​​obtained from the two tests as the apparent resin content of the tested molding material, and the difference between the two values ​​should not exceed 2.0% (absolute value).
Test report
The test report should include the following items: a. Comprehensive identification of the sample, b. The method used to make the molding compound into granules, c. The apparent resin content in each sample; d. The arithmetic mean of the values ​​obtained from the two samples and the test date.
Additional notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of the Chemical Method Subcommittee of the National Plastics Standardization Technical Committee.
This standard was drafted by Shanghai Plastic Factory. The main drafters of this standard are Dian Yichu and Shen Fengshu. 593
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