Decomposition method for bromine in bromine-based flame retardant agent

Abstract

The present invention discloses a decomposition method for bromine in a bromine-based flame retardant agent. The method comprises the following steps: 1, adopting a nickel crucible to directly weigh a sample, adding an emulsifier, and then adding a potassium hydroxide solution or a sodium hydroxide solution in a dropwise manner until the sample is uniformly soaked; 2, adding a small amount of grinded sodium carbonate to cover the surface of the sample, then adding grinded sodium hydroxide to cover the surface of the sample, covering the nickel crucible with a nickel crucible cover, wherein the covering is not sealed; 3, placing the crucible on a voltage regulating furnace and slowly heating until the sample is melted and absorbed in the alkali solution and no white powdery solid exists in the crucible; 4, closing the furnace, cooling the sample, add water until the height of the water is 1 / 3-1 / 2 height of the crucible, heating so as to dissolve all the melt in the water, transferring the resulting solution to a beaker, cleaning the nickel crucible and the cover, transferring the resulting cleaning liquid to the beaker; and 5, carrying out volume metering on the solution to provide a spare use for determination. The method of the present invention has the following advantages that: the used agents and the used instrument are simple and safe, the requirements on the analytical instrument are low, the disadvantages of easy splashing or overflow of the sample at the high temperature in the conventional method are avoided, the operation is convenient, the repeatability is good and the determination is accurate.

Description

Technical field [0001] The invention relates to a method for pre-treating and decomposing the bromine element in the process of determining the bromine element content in a flame retardant with high bromine content. Background technique [0002] Bromine-based flame retardants have good flame retardant effects, light stability and antistatic properties, and are widely used in polyolefin, polyamide, polystyrene and other plastics, fibers, and silicone rubber and other synthetic rubber materials. 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 and flame retardant effect of the product. [0003] The traditional methods for determination of bromine in organic bromides include sodium melting method, oxygen flask combustion method, potassium dichromate oxidation method, reduction method, sodium biphenyl method, etc. The o...

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Problems solved by technology

[0006] However, the measurement results tend to be too small, and the life of the nickel crucible is easily affected by too high a temperature. The main reason is that it is related to the high temperature melting temperature and the size of NaOH powder: if the temperature is too low, the decomposition is not complete; if the temperature is too high, it is easy to splash or overflow

Since the solid NaOH is a solid covering the sample, its pores are large, and the sample is easily washed out from the gap when it is heated, resulting in a decrease in absorption efficiency. Therefore, it needs to be ground into powder, and the gap will be reduced to completely cover the sample. It is easy to absorb water and get damp during the process, and the operation is troublesome

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