Invesigation Of Analytical Method For Bromine Content In Brominated Butyl Rubber

The content of bromine in brominated butyl rubber is an important parameter to evaluating the property of brominated butyl rubber owing to having the direct bearing on the crosslinking density of rubber during vulcanization,and relating to the reactivity of double bonds.Since the theoretical content of bromine is very low,the bromine content of brominated butyl rubber in general industrial grade is about 1.6%-2.0%,which brings a certain degree of difficulty to the inspection work.In order to accurately reflect its performance,it is necessary to select appropriate analytical methods to improve the accuracy of analysis.Among many analytical methods,the measured value of thermogravimetry is generally considered higher than actual value.The equipment of nuclear magnetic method is more than one million,and the maintenance cost is up to 100,000 per year.Therefore,several evaluation methods suitable for bromine content measurement in factories were studied in this paper.The content of bromine in brominated butyl rubber was measuredby oxygen bomb combustionchemical titration,oxygen bottle combustion-chemical titration,oxygen bottle combustion-ion chromatography and X-ray fluorescence spectrometry respectively.The analytical methods were compared and studied,and the uncertainty,precision and economic effects were evaluatedrespectively.The findings show that the test results of oxygen bomb combustion-chemical titration method are stable and reproducible;the test results of oxygen bottle combustion-visual titration method are not suitable for judging rubber grade owing to high uncertainty;the uncertainty of oxygen bomb combustion-ion chromatography method is better than that of visual titration method,but its equipment input and technological level of analysts are high requirment;compared with previous measurements,x-ray fluorescence spectrometry analysis is simple and stable,especially accurate for the analysis of bromine content in liquid colloidal samples,shorter time demand of testing,which has important guiding significance for plant production.