GB/T 40409-2021Flame retardant chemical—Tetrabromophthalate diol (English PDF)

6.2 Appearance

Load 50mL of specimen into a 50mL colorimetric tube. Visually inspect from the side under transmitted light conditions.

6.3 Hydroxyl value

Determine according to method A specified in GB/T 12008.3-2009.

The absolute deviation of the two parallel determination results is not more than 1.0mg/g. Take the arithmetic mean of two parallel determinations as the determination result.

6.4 Acid value

Determine according to the test method of GB/T 12008.5.

Take the arithmetic mean of two parallel determinations as the determination result. The absolute deviation of the two parallel determination results is not more than 0.1mg/g.

6.5 Bromine content

The absolute deviation of the two parallel determination results is not more than 0.2%.

Take the arithmetic mean of two parallel determinations. Round it to one decimal place as the determination result.

6.5.1 Method summary

Use potentiometric titration after alkali fusion to determine the bromine content in tetrabromophthalate diol. Under slightly acidic conditions, use silver nitrate standard titration solution to titrate the content of bromide ions. The titration end point is determined by the sudden jump point of electrode potential.

6.5.2 Reagents and solutions

6.5.2.1 Sodium hydroxide.

6.5.2.2 Potassium hydroxide.

6.5.2.3 Calcium carbonate.

6.5.2.4 Ethanol.

6.5.2.5 Silver nitrate standard titration solution (0.1mol/L).

6.5.2.6 Sodium hydroxide standard titration solution (1mol/L).

6.5.2.7 Bromothymol blue indicator solution (1g/L).

6.6 Moisture

Determine according to method A (manual titration) specified in GB/T 22313-2008.

The absolute deviation of the two parallel determination results is not more than 0.03%.

The arithmetic mean of two parallel determinations was taken as the determination result.

6.7 Viscosity

Determine according to the test method of GB/T 12008.7-2010.

The absolute deviation of the two parallel determination results is not more than 0.500Pa·s. Take the arithmetic mean of two parallel determinations as the determination result.

6.8 Density determination

Determine by the Webster balance method specified in GB/T 611.

The absolute deviation of the two parallel determination results is not more than 0.03g/mL. Take the arithmetic mean of two parallel determinations as the determination result.

7.1 Inspection items

All items specified in Chapter 5 are exit-factory inspection items. They shall be inspected in batches.

7.2 Batching rules

Tetrabromophthalate diol is taken as a batch of products from each production kettle or the same storage tank that is evenly mixed. Each batch of products does not exceed 50t.

7.3 Sampling rules

The number of sampling units is in accordance with the provisions of GB/T 6678. The sampling method is carried out according to the provisions of GB/T 6680. The sampling container is dry and clean. The total sampling volume shall not be less than 250mL.

Samples shall be divided into two clean, dry containers. Seal. Put on adhesive labels, indicating manufacturer's name, product name, classification, batch number or production date, sampling date and sampler's name. One is for inspection and the other for future reference. The storage time is determined by the manufacturer as needed.

7.4 Rules for determination and reinspection

7.4.1 Rules for determination

Tetrabromophthalate diol shall be inspected by the quality inspection department in accordance with the test methods specified in this document. Use the round-off value comparison method specified in GB/T 8170 to judge whether the inspection result conforms to this document. According to the inspection results and the requirements in this document, determine the quality of the product.

7.4.2 Rules for reinspection

If the inspection result does not meet the requirements of this document, the item shall be reinspected by double sampling. The reinspection results are used as the basis for the quality determination of this batch of products. Even if only one of the indicators in the reinspection result does not meet the requirements of this document, the whole batch of products is considered rejected.