A kind of method for reducing polychlorinated biphenyl content in diphenyldimethoxysilane

Abstract

The invention relates to a method for reducing polychlorinated biphenyl content in diphenyldimethoxysilane. The method comprises the following steps: S1, adding metal sodium into diphenyldimethoxysilane containing polychlorinated biphenyl, maintaining the temperature in an oil bath at a temperature of 100-105 DEG C, stirring for 5-6 hours, and cooling to room temperature; S2, regulating the pH value of the system to be 6-8 by using organic acids; and S3, filtering, and rectifying, thereby obtaining the diphenyldimethoxysilane product. With the adoption of the technical scheme, the method disclosed by the invention has the advantages that the metal sodium can be in a molten state at the temperature of 100-105 DEG C and has high enough activity, so that the metal sodium is easily reacted with chlorine in the polychlorinated biphenyl; acid used for regulating the pH value of the system is acetic acid, the formed salt is sodium acetate, and the diphenyldimethoxysilane product is not damaged in the subsequent distillation process so as not to cause product losses; and the by-product, namely sodium chloride or sodium acetate is not dissolved in the reaction system and is easily removed by filtration, and the industrial operation is simple.

Description

technical field [0001] The invention relates to a method for reducing polychlorinated biphenyl content in diphenyldimethoxysilane, wherein the diphenyldimethoxysilane is prepared by diphenyldichlorosilane alcoholysis. Background technique [0002] Polychlorinated biphenyls (PCBs) are currently one of the most serious pollutants harmful to the human environment. Diseases of the internal organs and affect the nervous, reproductive and immune systems. As early as 1991, China's Ministry of Energy and Environmental Protection Bureau issued documents to strictly control the use and disposal of products and wastes containing PCBs, and products containing PCBs higher than 50ppm must be disposed of. PCBs are listed in the 47 types of hazardous waste listed in the "National Hazardous Waste List" issued on January 4, 1998. On May 23, 2001, representatives of 127 countries and regions, including the Chinese government, signed the "Stockholm Convention" aimed at strictly prohibiting or...

AI Technical Summary

Problems solved by technology

The content of inorganic chlorine or polychlorinated biphenyls in diphenyldimethoxysilane products is too high, which will affect its application range, especially in some high-end fields.

[0005] Since the silicon-oxygen bond in diphenyldimethoxysilane is relatively active, it will undergo alkali hydrolysis and condensation under the action of alkali metal alkoxide (such as sodium methoxide) at high temperature, resulting in a large product loss, making it difficult to realize industrialization.

Therefore, the above methods are not suitable for dealing with PCBs in diphenyldimethoxysilane