Method for detecting content of bromine in fire retardant through automatic potentiometric titration

Abstract

The invention discloses a method for detecting content of bromine in fire retardant through automatic potentiometric titration, which comprises the steps of 1 utilizing nickel crucible to directly weigh a sample, adding emulsifier and potassium hydroxide solution or sodium hydroxide solution into the sample, and evenly infiltrating the mixture in advance; 2 after adding small amount of ground sodium carbonate on the surface of the sample to cover the sample, adding solid sodium hydroxide to cover the surface, covering a crucible cover on the crucible with gaps reserved; 3 slowly heating the sample on a pressure regulating electric stove and enabling the sample to fuse in alkali solution and absorb the alkali solution till no white powder solid exits in the crucible; 4 turning off the electric stove, enabling the test sample to cool down, adding water into the crucible till 1 / 2-1 / 3 of the height of the crucible, heating the water, enabling fusant to be completely melt in the water, transferring the mixture into a beaker, cleaning the nickel crucible and the cover and transferring cleaning solution into the beaker together; 5 metering the volume of the solution for standby measurement; and 6 utilizing the automatic potentiometric titrimetor, utilizing a silver / bromine iron selection electrode to serve as an indication electrode and utilizing silver nitrate (AgNO3) standard solution to titrate sample solution. The method for detecting the content of the bromine in the fire retardant through the automatic potentiometric titration has the advantages of being high in weighing accuracy, safe and reliable.

Description

technical field The invention relates to a method for bromine element pretreatment and content determination of flame retardants with high bromine content. Background technique Brominated flame retardants have good flame retardant effect, light stability and antistatic properties, and are widely used in polyolefin, polyamide, polystyrene and other plastics, fibers and synthetic rubber materials such as silicone rubber. Among them, the content of bromine element in the flame retardant system is an important parameter to evaluate the flame retardant performance of brominated flame retardants, and its size directly affects the quality of the product and the flame retardant effect. (1) Pretreatment technology: The traditional methods for the determination of bromine in organic bromides include sodium melting method, oxygen bottle combustion method, potassium dichromate oxidation method, reduction method, sodium biphenyl method, etc. Oxygen cylinder combustion method is adopted...

AI Technical Summary

Problems solved by technology

Since the preparation of brominated flame retardants usually uses chlorine-containing compounds as raw materials, chlorine atoms are inevitably introduced into the product, and some flame retardants with synergistic flame retardant effects also contain dihalogens such as bisphosphonate flame retardants. For plastics, the traditional precipitation titration method, silver method, etc. are used to measure the total amount of the two, which is difficult to achieve the purpose of truly evaluating the performance of flame retardants.

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