Reasons for yellowing of nitrile gloves
Recently, customers in the dust-free industry have called us to ask about nitrile gloves manufacturers: the reason for the yellowing of nitric acid gloves in clean room.
We know that acrylonitrile (AN) is one of the main polymerization monomers for the production of polymer materials such as nitrile rubber gloves. The quality of acrylonitrile directly affects the performance of its post-processed products, among which the content of oxazole in acrylonitrile is the most. The key is that it not only affects the color and storage stability of acrylonitrile, but also the color of the polymer material after synthesis. Relevant test data show that the oxazole content of acrylonitrile exceeding 75mg/kg may cause some chemical reactions of acrylonitrile. That is to say, if the content of acrylonitrile oxazole in the glove exceeds the standard, yellowing will occur. First, there is a problem with the color of the finished product. Second, the color will change after a period of storage.
How to analyze the content of oxazole in acrylonitrile and what are the methods?
The most common methods are chemical, spectroscopy and chromatography, but the most effective method is to use gas-mass spectrometry (GC-MS). In this experiment, the capillary column which is suitable for the analysis of trace oxazole and other impurities in acrylonitrile was screened, and the oxazole was determined by gas-mass spectrometry (GC-MS). The chemical method was used to verify the effective carbon number. The mass correction factor of oxazole was calculated by the method and quantified by internal standard method. The method is applied in the technical issue of reducing the content of oxazole in acrylonitrile by glove manufacturers and petrochemical companies, and satisfactorily solves the quality problem of acrylonitrile polymerization products - nitrile and acrylic yellowing, and the effect is satisfactory.
The method is applied in the study of the cause of yellowing of nitrile in domestic industry. The oxazole content in the raw material acrylonitrile is high, about 0.03%~0.12%. According to the analysis data,
At present, our company has modified the acrylonitrile production and refining process. After the modification, the oxazole content in acrylonitrile is reduced to less than 0.007%, and the chromaticity of acrylonitrile is reduced from 45 to 48~ to less than 20. After the acrylonitrile refining process is reformed, The chromaticity of acrylonitrile polymer acrylic fiber decreased from 0.24~0.27 to 0.10~0.11, which satisfactorily solved the quality problem of acrylic yellowing and achieved good results.
In summary, there are different proportions of oxazole in the acrylonitrile material for making gloves, and the higher the content, the more the performance and color of the final product can be affected. So how to control the content of oxazole is very important.
The above is the yellowing of nitrile gloves, I hope to help everyone!