GB/T 9345.1-2008 English PDF (GB/T9345.1-2008)

GB/T 9345.1-2008: Plastics -- Determination of ash -- Part 1: General methods
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GB/T 9345.1-2008
Plastics - Determination of ash - Part 1. General methods
ICS 83.080.01
G32
National Standards of People's Republic of China
GB/T 9345.1-2008/ISO 3451-1.1997
Replace GB/T 9345-1988
Determination of plastic ash
Part 1. General method
(ISO 3451-1.1997, IDT)
Released on.2008-08-14
2009-04-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
China National Standardization Administration issued
Foreword
GB/T 9345 "Determination of plastic ash" is divided into five parts.
--- Part 1. General method;
---Part 2. Polyalkylene terephthalate;
---Part 3. Unplasticized cellulose acetate;
---Part 4. Polyamides;
--- Part 5. Polyvinyl chloride.
This part is the first part of GB/T 9345, corresponding to ISO 3451-1.1997 "Plastics - Determination of ash - Part 1.
General Method (1997 English version). This section is equivalent to ISO 3451-1.1997.
For ease of use, the following editorial changes have been made to this section.
a) Change the word “this International Standard” to “this standard” or “GB/T 9345” and change the “this part of ISO 3451” to “GB/T 9345”.
This part" or "this part";
b) removed the preface to ISO 3451-1.1997;
c) added a preface to this part of the national standard;
d) replace the decimal point symbol "," in the international standard with the decimal point symbol "." in our country;
This part replaces GB/T 9345-1988 "General method for determination of plastic ash".
Compared with GB/T 9345-1988, the main changes in this section are as follows.
--- Increased precision data;
--- Adding a fume hood to the device;
--- Added warnings after the reagents involved in personal safety.
This section was proposed by the China Petroleum and Chemical Industry Association.
This part is under the jurisdiction of the National Plastics Standardization Technical Committee General Method and Product Branch of Plastic Resins (TC15/SC4).
This section is responsible for drafting units. National Synthetic Resin Quality Supervision and Inspection Center, Beijing Yanhua Petrochemical Co., Ltd. Resin Application
graduate School.
Participated in the drafting of this section. National Petrochemical Organic Raw Materials Synthetic Resin Quality Supervision and Inspection Center, National Chemical Building Materials Testing
Heart, National Plastic Products Quality Supervision and Inspection Center (Beijing), National Plastic Products Quality Supervision and Inspection Center (Fuzhou), Zhonghao Chenguang Chemical Research
Research Institute, Guangzhou Blonde Technology Co., Ltd., etc.
The main drafters of this section. Zheng Ning, Wang Jiandong, Chen Hongyuan, Liu Yuchun, Liu Shansheng, He Wei.
The previous versions of the standards replaced by this section are.
---GB/T 9345-1988.
GB/T 9345.1-2008/ISO 3451-1.1997
Determination of plastic ash
Part 1. General method
1 range
This part of GB/T 9345 specifies general methods for determining ash in various plastics (resins and mixtures) and suitable test conditions.
The specific conditions selected for a material can be specified in the material specification for the plastic.
Specific test conditions for plastics containing reinforcing glass fibers, fillers and/or certain additives will be specified in GB/T 9345.
It is specified in other parts of the type of plastic (see the preface).
2 Principle
There are three basic methods for determining the ash content of organic matter.
a) Direct calcination (Method A), ie burning organic matter and calcining the residue at elevated temperature until constant weight.
b) Calcination followed by calcination. There are two different steps that can be used.
--- After the combustion of sulfuric acid treatment, that is, after burning organic matter, the inorganic residue is treated with concentrated sulfuric acid to convert it into sulfate, and then at high temperature
The residue was calcined to a constant weight. This method is the general method of "sulfated ash" (Method B).
--- Pre-combustion sulfuric acid treatment, that is, heating the organic matter together with concentrated sulfuric acid to smoke, then burning the organic matter, and finally calcining at high temperature
The residue was burned until constant weight (Method C). The method is applicable to organic substances containing volatile metal halides due to these halogens
The compound is volatile when burned, but is not suitable for silicon-containing or fluoropolymers.
The final step of each method is to calcine at 600 ° C, 750 ° C, 850 ° C or 950 ° C until constant weight (see 5.2).
3 reagents (for method B and method C only)
Only analytically pure reagents and distilled water or water of equivalent purity can be used during the analysis.
3.1 Ammonium carbonate, anhydrous.
3.2 Ammonium nitrate, a solution with a mass fraction of about 10%.
3.3 Sulfuric acid with a density of 1.84 g/cm3.
Warning. Be careful when handling.
3.4 Sulfuric acid, a 50% volume fraction solution.
Warning. Be careful when handling.
4 instruments
4.1 坩埚, quartz crucible, ceramic crucible or platinum crucible that does not chemically interact with the test substance.
4.2 Bunsen burners or other suitable heating sources.
4.3 Muffle furnace or microwave oven can be controlled in the range of 600 °C ± 25 °C, 750 °C ± 50 °C, 850 °C ± 50 °C or 950 °C ± 50 °C.
4.4 Analytical balance, the graduation value is 0.1mg.
4.5 Pipettes, suitable for use in Method B and Method C only.
4.6 Dryer, a high-efficiency desiccant that does not react with ash.
Note. If the ash's affinity for water is greater than the affinity of the selected desiccant for water, choose a more effective desiccant.
4.7 Weighing bottles.
4.8 Fume hood.
GB/T 9345.1-2008/ISO 3451-1.1997
5 steps
5.1 Sample size
The amount of sample taken is sufficient to produce 5 mg to 50 mg of ash. If the approximate content of ash is unknown in advance, a pre-preparation is required.
Determination.
Table 1 gives the recommended sample size.
Table 1 Recommended sample volume
Approximate ash content (if known) /% sample amount/g ash content/mg
≤0.01
>0.01～0.05
>0.05～0.1
>0.1～0.2
>0.2
≥200
≤10
5 to 50
10~50
25~50
25~50
20~50
For plastics with a small amount of ash, the amount of sample must be increased. When the sample cannot be burned once, it is once in a suitable weighing bottle.
The required amount is weighed, and then an appropriate amount of the sample is added to the crucible (4.1) for continuous combustion until all the samples are burned out.
5.2 Test conditions
It shall be continuously calcined to constant weight as specified in 5.3.6, but the cumulative time of calcination at the specified temperature in the muffle furnace (4.3) shall not exceed 3 h.
The choice of calcination temperature and the choice of sulfation treatment depends on the nature of the plastic and the additives it may contain. If in each
If you choose between the conditions that meet the requirements, you should choose a condition of constant weight if you choose less than 3h. Treated with higher temperature or sulfation
The duration of calcination can often be shortened.
Regardless of method A, method B or method C, unless there are special technical or commercial reasons for the use of other temperatures, usually the most
The post-calcination temperature should be selected from one of the following temperature series.
600 ° C ± 25 ° C, 750 ° C ± 50 ° C, 850 ° C ± 50 ° C, 950 ° C ± 50 ° C.
The ashing operation should be carried out in a fume hood.
5.3 Method A---Direct Calcination
5.3.1 Place the crucible (4.1) in the muffle furnace (4.3) and heat to constant weight at the test temperature. Put it in the dryer (4.6) at least
After 1 h, it was allowed to cool to room temperature and weighed on an analytical balance (4.4) to the nearest 0.1 mg.
5.3.2 Put a sample of pre-dried or known volatile content according to the relevant material specifications into a weighing bottle of known quality (4.7)
in. Weighing, accurate to 0.1mg or 0.1% of the sample amount, the amount of the sample is determined to produce 5mg ~ 50mg ash. If 坩
If the crucible is large enough to hold a sample equivalent to 5 mg to 50 mg of ash, the sample can be directly weighed in a crucible. Larger
The material can be pressed into small pieces and then broken into pieces of suitable size.
5.3.3 Place the sample in the crucible, not more than half the height of the crucible, and then directly on the Bunsen burner or other suitable heating source (4.2)
Heat to slowly burn it. Burning should not be too intense to avoid loss of ash particles. After cooling, the remaining samples were added. Repeat the above operation
Until the entire sample is burned.
5.3.4 Place the crucible in a muffle furnace that has been preheated to the specified temperature and calcine for 30 minutes.
5.3.5 Place the crucible in a desiccator for 1 h, or allow it to cool to room temperature and weigh on an analytical balance (4.4) to the nearest 0.1 mg.
5.3.6 Under the same conditions, calcination for 30 min, until constant weight, that is, the difference between the two successive weighing results is not more than 0.5 mg.
5.4 Method B---After combustion, treated with sulfuric acid and then calcined
5.4.1 Operate in accordance with the provisions of 5.3.1 to 5.3.3.
5.4.2 After cooling, add the sulfuric acid solution (3.4) dropwise with a pipette (4.5) of appropriate capacity to completely wet the residue and heat it to no risk.
Until the smoke, avoid excessive boiling.
GB/T 9345.1-2008/ISO 3451-1.1997
5.4.3 If there is still a trace of carbonaceous material after cooling, add one to five drops of ammonium nitrate solution (3.2) and heat until no white smoke is emitted.
5.4.4 In order to turn the metal oxide formed in the above step into sulfate, add about five drops of concentrated sulfuric acid (3.3) after cooling and heat to
Do not smoke white smoke. Avoid violent boiling or loss of ash due to large amounts of smoke.
5.4.5 After cooling, add 1g ~ 2g anhydrous ammonium carbonate (3.1), and heat until no more smoke, avoid ash damage during heating
Lost. Then, the crucible is placed in a muffle furnace preheated to a predetermined temperature, and operated in accordance with the provisions of 5.3.4 to 5.3.6.
5.5 Method C---Processing with sulfuric acid before combustion and then calcining
5.5.1 This method does not apply to silicon-containing or fluoropolymers.
5.5.2 Operate in accordance with the provisions of 5.3.1 and 5.3.2.
5.5.3 Place the sample in the crucible, not more than half the height of the crucible. Use a pipette (4.5) to add enough concentrated sulfuric acid (3.3) to make it completely
Wetting material. Cover the crucible with a watch glass and heat it directly on a Bunsen burner with a small fire until the organic matter begins to decompose.
Continue to heat carefully, adjust the watch glass to allow the soot to escape, and ensure that no ash-containing material is lost. For the loss of ash-containing substances
For trending plastics, it is recommended to place the sample containing the sample on an orifice plate made of heat-resistant material (such as ceramic fiber) and heat it only with a small fire.
Make organic matter only smoke without burning. If the sample initially placed in the crucible is not sufficient to produce the desired ash content, then after cooling, add
Into another portion of the sample, repeat the above procedure until all the samples are burned in the crucible. Remove the watch glass and ensure that no solid particles adhere
On the watch glass.
When sulfuric acid has a tendency to spread to the mouth of the mouth, or despite some care, there are still some samples that have a tendency to lose due to the violent reaction (poly
In the case of vinyl chloride, the mixed acid of concentrated acetic acid and concentrated sulfuric acid can be used instead of concentrated sulfuric acid. The use of mixed acid should be agreed by the relevant parties and
Indicated in the test report.
5.5.4 Operate in accordance with the provisions of 5.4.3 to 5.4.5.
6 trials
The number of tests and the dispersion allowed by the test results shall be specified in the relevant standards for each material, if not specified in the relevant standards,
A second measurement is carried out, and if necessary, the test is repeated until the difference between successive secondary measurements is not more than 10% of the average value.
7 results are expressed
The ash or sulfated ash is expressed in mass fraction, and the value is expressed in %, given by equation (1).
100 (1)
In the formula.
8 precision
Precision data has been tested in eight laboratories using eight different materials. The results are summarized in Table 2.
Table 2 Summary of precision data
HDPE/anti-blocking agent
LDPE/anti-blocking agent
LDPE/anti-blocking agent
LDPE/anti-blocking agent
PET/SiO2
0.015
0.149
0.437
1.00
3.18
0.0038
0.0047
0.0047
0.0090
0.0448
0.0052
0.0054
0.0059
0.0090
0.0448
0.0107
0.0132
0.0131
0.0253
0.1253
0.0146
0.0151
0.0165
0.0253
0.1253
GB/T 9345.1-2008/ISO 3451-1.1997
Book GB/T 9345.1-2008/ISO 3451-1.1997
Table 2 (continued)
PET/T iO2
PA/glass
PET/T iO2
12.46
33.16
44.81
0.0461
0.2715
0.3707
0.0515
0.2822
0.4000
0.1292
0.7602
1.0379
0.1441
0.7902
1.1201
among them.
SR---standard deviation of reproducibility;
The absolute difference between two individual test results with a confidence level of 95% should be lower than the value;
R---Reproducibility limit, that is, the confidence level obtained under reproducibility test conditions (different operators, different instruments, different laboratories) is 95%
The absolute difference between the two individual test results should be lower than the value.
9 test report
The test report should include the following.
a) indicate this part of GB/T 9345;
b) the complete identification of the test material;
c) indicate the test method used (Method A, Method B or Method C); if using ...