Analysis And Characterization Of The Antioxidant Component In Nitrile Rubber

Nitrile butadiene(NBR)rubber is a random copolymer obtained by emulsion polymerization of acrylonitrile and butadiene.NBR will age under the action of oxygen,ozone,light,heat or metal elements,and its performance will degrade significantly.In general,a certain amount of antioxidant will be added to NBR to delay or prevent its aging.It was found that the residual free nonylphenol(NP)in decomposed trinonylphenyl phosphates(TNPP),an antioxidant commonly used in NBR industry,could lead to the excessive NP content in NBR rubber products.With the increasingly strict environmental protection requirements at home and abroad,the environmental protection of NBR is an inevitable trend in the future.As one of the key additives of NBR,antioxidant has an important influence on the production cost and product quality stability of NBR.In this study,two main compound antioxidants were qualitatively analyzed and the main component information was determined,which provided the experimental basis for the pretreatment of NBR samples and the structure of antioxidant.On this basis,three kinds of typical solid NBR products were selected from abroad,and five kinds of sample pretreatment methods were developed for the extraction,separation,analysis and characterization of antioxidant system,including exploring the best extraction conditions,sample pretreatment,and qualitative and quantitative analysis.The results show that acetone is the best solvent for NBR.The method of freezing grinding extraction was selected for sample pretreatment.Based on the qualitative analysis by gas chromatography-mass spectrometry(GC-MS)and the quantitative analysis by comparing with the self-built standard antioxidant spectrum library,a method for the analysis and characterization of the antioxidant system in solid NBR was established.It is found that the methods for the analysis and characterization of the antioxidant system of solid NBR have good specificity,detection limit,linear range and precision,which can be applied to the analysis and characterization of the antioxidant system of NBR.