Method for detecting total pH value and chloride ion content of vinyl chloride monomer

Abstract

The invention discloses a vinyl chloride monomer sampling device. The vinyl chloride monomer sampling device comprises a sample bottle, a protective cover and a sampling valve, the invention further discloses a method for detecting the total pH value and the chloride ion content in the vinyl chloride monomer. A used detection sample preparation device comprises the vinyl chloride monomer samplingdevice. The invention has the advantages that 1) the safety of vinyl chloride monomer sampling operation is improved; 2) the representativeness and authenticity of the sample can be guaranteed, and the accuracy of a detection result can be improved; 3) the device is simple and convenient to operate, and realizes convenient sampling of vinyl chloride monomers; (4) hydrogen ions, hydroxyl ions and chloride ions in the sampling container are directly extracted through magnetic stirring for the first time, the vinyl chloride monomer is gasified and discharged, and the total pH value and chloride ion content of the residual solution are detected by adopting a potentiometric titration method and a back titration method; and 5) the detection result can truly reflect the total pH value and chloride ion content in the vinyl chloride monomer.

Description

technical field [0001] The invention relates to a vinyl chloride production process, in particular to a vinyl chloride monomer sampling and detection method. Background technique [0002] Polyvinyl chloride resin is one of the five general-purpose plastics. It is widely used in construction, industry, agriculture, daily necessities, automobile decoration and home appliances. my country has the largest production capacity in the world. Vinyl chloride is a monomer for the synthesis of polyvinyl chloride resin. Vinyl chloride is a colorless, liquefied gas with a boiling point of -13.8°C. It forms an explosive mixture with air, and the volume explosion limit is 3.6-33%. Vinyl chloride is a toxic substance, long-term inhalation and exposure to vinyl chloride may cause liver cancer. [0003] Since the total pH and chloride ion content of vinyl chloride monomer directly affect the production process control and resin quality of polyvinyl chloride resin, accurate detection of total...

AI Technical Summary

Problems solved by technology

The former because the sampling container is directly connected to the outside atmosphere, a large amount of volatilization of low-boiling vinyl chloride monomer will endanger the safety and health of personnel, and it is difficult to accurately measure the sampling amount of vinyl chloride monomer; the latter is difficult to observe the appearance of the sample during the sampling process because the steel cylinder is opaque and control the sampling volume of samples, or it is not easy to clean, and there may be metal leaching substances such as iron, which will affect the quality of vinyl chloride monomer and make the test results inaccurate

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