Industrial Propylene Glycol Methyl Ether Acetate (3)

4.

4.

The laboratory samples were diluted with absolute ethanol , titrated with sodium hydroxide standard titration solution using phenolphthalein as an indicator, and the acidity was calculated based on the volume of the sodium hydroxide standard titration solution consumed

4.

4.

4.

4.

4.

Micro burette: 10mL, divided into 0.

4.

Measure 50 mL of ethanol in a 250 mL conical flask, add 2 to 5 drops of phenolphthalein indicator, shake well, and titrate with sodium hydroxide standard titration solution until the solution is pink

4.

The acidity is calculated as the mass fraction w ₁ of acetic acid (CH ₃ COOH) , and the value is expressed in %, calculated according to formula (2):

Where:

V— The value of the volume of the sodium hydroxide standard titration solution (4.

c—The exact value of the concentration of sodium hydroxide standard titration solution, the unit is moles per liter (mol/L);

M— The value of the molar mass of acetic acid , in grams per mole (g/mol) (M=60.

m—The value of the mass of the sample, in grams (g)

Take the arithmetic mean of the two parallel determination results as the determination result, and the absolute difference between the two parallel determination results shall not exceed 0.
003%
.

4.
5 Determination of moisture

According to the provisions of GB/T6283-1986
.
Other methods that can achieve the same analysis accuracy can be used
.

Take the arithmetic mean of the two parallel determination results as the determination result, and the absolute difference between the two parallel determination results shall not be greater than 10% of the arithmetic mean of the two determination values
.

4.
6 Determination of density

According to the provisions of the density meter method in GB/T4472-1984
.

Take the arithmetic average of the two parallel determination results as the determination result, and the absolute difference between the two parallel determination results shall not exceed 0.
0005 g/cm ³
.

4.
7 Determination of boiling range

According to the provisions of GB/T7534-2004
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In the calculation of the result, the correction step of the pressure deviation from the standard atmospheric pressure can be ignored
.

5 Inspection rules

5.
1 All items specified in the requirements in Chapter 3 are factory inspection items
.

5.
2 A batch of products of the same quality can be grouped according to product storage tanks or according to the production cycle
.
Each batch of products does not exceed 20t
.

5.
3 Sampling shall be carried out in accordance with the provisions of GB/T6678-2003 and GB/T6680-2003
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The total sampling volume is not less than 1000mL
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Divide the sample into two evenly, put it into a clean and dry glass bottle, seal it tightly, and label it
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The label should indicate the product name, batch number, sampling date and the name of the sampler
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One bottle is for inspection and the other bottle is kept for future reference
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5.
4 Propylene glycol methyl ether acetate for industrial use should be inspected by the quality supervision and inspection department of the manufacturer
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The manufacturer shall ensure that each batch of products manufactured meets the requirements of this standard
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Each batch of products should be accompanied by a certificate of quality of certain formats, including: manufacturer name, product name, lot number or production date, net content and standard number and so on
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5.
5 The test result is judged according to the rounding value comparison method specified in GB/T1250
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If any indicator of the inspection result does not meet the requirements of this standard, the sampling shall be redoubled for inspection
.
Even if only one index does not meet the requirements of this standard as the result of the re-inspection, the whole batch of products shall be treated as unqualified
.

6 Marking, packaging, transportation and storage

6.
1 Industrial use of propylene glycol methyl ether acetate packaging containers should have a firm logo, indicating the product name, manufacturer name, site, trademark, batch number or date of production, net content, the number of this standard and the "easy" specified in GB190-1990 Flammable liquid" sign
.

6.
2 Propylene glycol methyl ether acetate for industrial use should be packaged in clean and dry galvanized iron drums or plastic drums.
The net content error of each drum shall not exceed 0.
5% of the calibrated net content
.

6.
3 Propylene glycol methyl ether acetate for industrial use should be covered during transportation to prevent exposure to the sun
.
The transportation and loading and unloading should be carried out in accordance with the regulations on the transportation of dangerous goods, with gentle lifting and handling, to avoid damage and accidents
.

6.
4 Propylene glycol methyl ether acetate for industrial use should be stored in a cool, dry, ventilated place, isolated from heat sources, and stored separately from substances that conflict with each other
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Under the packaging, transportation and storage conditions of this standard, the shelf life of industrial propylene glycol methyl ether acetate is 6 months from the date of production
.

It can be re-inspected after the expiry date, and it can still be used if the inspection result meets the requirements of this standard
.

7 Security

7.
1 Danger warning

Propylene glycol methyl ether acetate is a flammable liquid with a boiling point of 146°C, a flash point of 47°C to 48°C (closed cup), a self-ignition temperature of 380°C, and an explosion limit in the air of 1.
5% to 7.
0% (volume fraction)
.
Propylene glycol methyl ether acetate reacts with oxidants and is dangerous to burn; it will cause combustion and explosion when exposed to open flames and high heat; it will decompose and generate toxic gases during combustion
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Propylene glycol methyl ether acetate is irritating to eyes, skin and respiratory tract
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7.
2 Safety measures

Avoid contact with propylene glycol methyl ether acetate
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Eye contact: Rinse with plenty of water for more than 15 minutes, then seek medical attention
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Skin contact: Take off contaminated clothes, rinse the skin with plenty of water or shower
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Inhalation: Move to a ventilated environment.
If you have difficulty breathing, you can inhale oxygen; if there are persistent adverse reactions, seek medical attention
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Mistake: Rinse mouth immediately, dilute with clean water, and seek medical attention
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